Sustainable CO2 adsorbents prepared by coating chitosan onto mesoporous silicas for large-scale carbon capture technology

In this article, we report a new sustainable synthesis procedure for manufacturing chitosan/silica CO2 adsorbents. Chitosan is a naturally abundant material and contains amine functionality, which is essential for selective CO2 adsorptions. It is, therefore, ideally suited for manufacturing CO2 adsorbents on a large scale. By coating chitosan onto high-surface-area mesoporous silica supports, including commercial fumed silica (an economical and accessible reagent) and synthetic SBA-15 and MCF silicas, we have prepared a new family of CO2 adsorbents, which have been fully characterised with nitrogen adsorption isotherms, thermogravimetric analysis/differential scanning calorimetry, TEM, FTIR spectroscopy and Raman spectroscopy. These adsorbents have achieved a significant CO2 adsorption capacity of up to 0.98 mmol g−1 at ambient conditions (P=1 atm and T=25 °C). The materials can also be fully regenerated/recycled on demand at temperatures as low as 75 °C with a >85 % retention of the adsorption capacity after 4 cycles, which makes them promising candidates for advanced CO2 capture, storage and utilisation technology

Electric Vehicle Charging Station Placement: Formulation, Complexity, and Solutions

To enhance environmental sustainability, many countries will electrify their transportation systems in their future smart city plans. So the number of electric vehicles (EVs) running in a city will grow significantly. There are many ways to re-charge EVs' batteries and charging stations will be considered as the main source of energy. The locations of charging stations are critical; they should not only be pervasive enough such that an EV anywhere can easily access a charging station within its driving range, but also widely spread so that EVs can cruise around the whole city upon being re-charged. Based on these new perspectives, we formulate the Electric Vehicle Charging Station Placement Problem (EVCSPP) in this paper. We prove that the problem is non-deterministic polynomial-time hard. We also propose four solution methods to tackle EVCSPP and evaluate their performance on various artificial and practical cases. As verified by the simulation results, the methods have their own characteristics and they are suitable for different situations depending on the requirements for solution quality, algorithmic efficiency, problem size, nature of the algorithm, and existence of system prerequisite.Comment: Submitted to IEEE Transactions on Smart Grid, revise

Growing importance of valvular heart disease in the elderly

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Design, analysis, and testing of high frequency passively damped struts

Objectives of the research are: (1) to develop design requirements for damped struts to stabilize control system in the high frequency cross-over and spill-over range; (2) to design, fabricate and test viscously damped strut and viscoelastically damped strut; (3) to verify accuracy of design and analysis methodology of damped struts; and (4) to design and build test apparatus, and develop data reduction algorithm to measure strut complex stiffness. In order to meet the stringent performance requirements of the SPICE experiment, the active control system is used to suppress the dynamic responses of the low order structural modes. However, the control system also inadvertently drives some of the higher order modes unstable in the cross-over and spill-over frequency range. Passive damping is a reliable and effective way to provide damping to stabilize the control system. It also improves the robustness of the control system. Damping is designed into the SPICE testbed as an integral part of the control-structure technology

Avoid illegal encrypted DRM content sharing with non-transferable re-encryption

Digital rights management (DRM) technology enables valuable electronic media content distribution while preserving content providers' rights and revenues. Traditional DRM system utilizes security techniques to restrict copying of media content or allow only a single copy to be made. However consumers are demanding for the right to make copies for personal use or the right to use content on any device. Several DRM infrastructures have been proposed for secure content sharing. These infrastructures usually require cooperation and participation of both DRM technology providers and content providers; however there is a popular flaw in these schemes: the malicious employees of DRM technology providers can distribute DRM enabled contents to any consumers or make copies of a purchased content accessible to any devices without letting content provider know, thus reducing content providers' benefit. In this paper, we propose a novel DRM infrastructure which is based on a non-transferable re-encryption scheme to solve the above problem inherent in existing DRM infrastructures. In the proposed infrastructure, DRM technology providers and content providers are required to cooperate to make a purchased digital content for a specific device accessible by other different devices, and get extra profit from providing such services. The system preserves DRM technology providers and content providers' security properties while achieving secure and mutual profitable DRM content sharing. Furthermore, we allow content providers to trace the content, and control the content sharing rights. Even when malicious employees in DRM technology providers and DRM agent collude, they cannot re-delegate access rights to any device without permission from content provider, thus preserving content provider's benefit. © 2011 IEEE.published_or_final_versionThe IEEE 13th International Conference on Communication Technology (ICCT 2011), Jinan, China, 25-28 September 2011. In Proceedings of the 13th ICCT, 2011, p. 703-70

Measurement of collective flow in heavy ion collisions using particle pair correlations

We present a new type of flow analysis, based on a particle-pair correlation function, in which there is no need for an event-by-event determination of the reaction plane. Consequently, the need to correct for dispersion in an estimated reaction plane does not arise. Our method also offers the option to avoid any influence from particle misidentification. Using this method, streamer chamber data for collisions of Ar+KCl and Ar+BaI2 at 1.2 GeV/nucleon are compared with predictions of a nuclear transport model