Thermal properties comparison of hybrid CF/FF and BF/FF cyanate ester-based composites

[EN] Insights within thermal expansion, conductivity, and decomposition dependencies with temperature on symmetrical and unsymmetrical layered carbon (CF) or basalt (BF) fabrics in combination with flax fibers (FF) were approached. Driven by commercial application and environmental concerns, the paper draws attention on a modified formula of cyanate ester with a common epoxy resin under an optimized ratio of 70:30 (vol%) as well as on the hybrid reinforcements stacking sequences. Synergetic effects were debated in terms of the CF and BF stacking sequences and corresponding volume fraction followed by comparisons with values predicted by the deployment of hybrid mixtures rules (RoHM/iRoHM). CF hybrid architectures revealed enhanced effective thermophysical properties over their BF counterparts and both over the FF-reinforced polymer composite considered as a reference. Thermal conductivities spread between 0.116 and 0.299 W m-1 K-1 from room temperature up to 250 C on all hybrid specimens, giving rise to an insulator character. Concerning the coefficient of thermal expansion, CF hybrid architectures disclosed values of 1.236 10-6 K-1 and 3.102 10-6 K-1 compared with BF affine exhibiting 4.794 10-6 K-1 and 6.245 10-6 K-1, respectively, with an increase in their volume fraction.The corresponding author gratefully acknowledges the financial assistance of German Academic Exchange Service-DAAD that enabled and supported the internship with Fraunhofer Research Institution for Polymeric Materials and Composites-PYCO, Germany. Many thanks go to Dr. Christian Dreyer and Dr. Maciej Gwiazda for the resin formula and access to the composite manufacturing technology.Motoc, DL.; Ferrándiz Bou, S.; Balart, R. (2018). Thermal properties comparison of hybrid CF/FF and BF/FF cyanate ester-based composites. 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Low-energy particle events associated with sector boundaries

Onsets of some 40 to 45 low-energy proton events during the years 1957–1969 coincided in time with transits of well-defined sector boundaries across the Earth. These events can be interpreted as long-lived proton streams filling up some of the magnetic sectors, indicating an acceleration of protons which is not associated with typical proton-producing flares. The sharp onsets of these particle streams, as well as a deficiency of flare-associated particle events shortly before the boundary transit, indicate that in some cases magnetic sector boundaries can inhibit transverse propagation of low-energy particles in the solar corona or in interplanetary space.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43744/1/11207_2004_Article_BF00155310.pd

Increased epithelial cell proliferation in the ileal pouch mucosa of patients with familial adenomatous polyposis

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Interaction management between social agents and human

In this paper we address the problem of managing social interactions between a human user and a set of social agents in structured environments. These agents have to regulate a measurable characteristic of the user. Our study focuses mainly therapeutic, caring for elderly people and assessment applications. The agent concept considered in this study is suitable for multi-robot systems (physical, service, mobile or not), but also to virtual agents (avatars) in a virtual reality (VR) application. The proposed approach has been adapted for an application of social phobia treatment using virtual reality. Thus, we conducted a case study to show the effectiveness of our contribution

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