HNBR and its MWCNT reinforced nanocomposites : Crystalline morphology and electrical response

Morphology and electrical response of hydrogenated acrylonitrile butadiene rubber (HNBR) and its multiwall carbon nanotube (MWCNT) reinforced nanocomposites were studied by means of x-ray diffraction and broadband dielectric spectroscopy. HNBR systems were found to be semi-crystalline, with their crystallinity to increase with the addition of MWCNTs. In their dielectric spectra, four relaxation processes were detected. Ascending in relaxation time, these were attributed to: (i) interfacial polarization at the interface of crystalline and amorphous regions of HNBR and at the interface between HNBR and MWCNTs, (ii) glass to rubber transition of the amorphous part of HNBR, (iii) rearrangement of polar side groups, such as –CN, and (iv) local motions of small segments of the main elastomer chain. Electrical conductivity increases with MWCNT content and frequency increasing. The effect of temperature, on the electrical response, is more pronounced at low frequencies. The temperature dependence of the electrical conductivity strongly deviates from a pure Arrhenius behavior, signifying that the occurring conductance mechanisms do not correspond to a single thermally activated process. Relaxation dynamics imply that crystalline regions exert motion restrictions to large segments of the macromolecules in the amorphous phase and to polar parts of the systems

Public Narratives and the Construction of Memory Among European Muslims

This chapter draws on group and individual interviews with 735 European Muslims in 5 European countries and explores some key aspects of the politics of memory that form an inextricable component of European Muslim self-definitions, discourses and narratives deployed in the attempt to negotiate their inclusion in European societies

Impact of dietary organic acids and botanicals on intestinal integrity and inflammation in weaned pigs

BACKGROUND: Organic acids, such as citric and sorbic acid, and pure plant-derived constituents, like monoterpens and aldehydes, have a long history of use in pig feeding as alternatives to antibiotic growth promoters. However, their effects on the intestinal barrier function and inflammation have never been investigated. Therefore, aim of this study was to assess the impact of a microencapsulated mixture of citric acid and sorbic acid (OA) and pure botanicals, namely thymol and vanillin, (PB) on the intestinal integrity and functionality of weaned pigs and in vitro on Caco-2 cells. In the first study 20 piglets were divided in 2 groups and received either a basal diet or the basal diet supplemented with OA + PB (5 g/kg) for 2 weeks post-weaning at the end of which ileum and jejunum samples were collected for Ussing chambers analysis of trans-epithelial electrical resistance (TER), intermittent short-circuit current (I(SC)), and dextran flux. Scrapings of ileum mucosa were also collected for cytokine analysis (n = 6). In the second study we measured the effect of these compounds directly on TER and permeability of Caco-2 monolayers treated with either 0.2 or 1 g/l of OA + PB. RESULTS: Pigs fed with OA + PB tended to have reduced I(SC) in the ileum (P = 0.07) and the ileal gene expression of IL-12, TGF-β, and IL-6 was down regulated. In the in vitro study on Caco-2 cells, TER was increased by the supplementation of 0.2 g/l at 4, 6, and 14 days of the experiment, whereas 1 g/l increased TER at 10 and 12 days of treatment (P < 0.05). Dextran flux was not significantly affected though a decrease was observed at 7 and 14 days (P = 0.10 and P = 0.09, respectively). CONCLUSIONS: Overall, considering the results from both experiments, OA + PB improved the maturation of the intestinal mucosa by modulating the local and systemic inflammatory pressure ultimately resulting in a less permeable intestine, and eventually improving the growth of piglets prematurely weaned

The use of augmented reality games in education: a review of the literature

This paper provides a review of the literature about the use of augmented reality in education and specifically in the context of formal and informal environments. It examines the research that has been conducted up to date on the use of those games through mobile technology devices such as mobile phones and tablets, both in primary and secondary education. The review of the relative literature was carried out in the period 2000 to early 2014 in ScienceDirect and ERIC. The outcomes of this review illustrated a set of studies that provide evidence of positive outcomes regarding student learning. These studies, which focused mainly on the natural sciences and took place within informal learning environments, used both qualitative and quantitative data collection methods. The earliest study that was conducted about this topic used personal digital assistants, while the more recent one used smart (mobile) phones and tablets. The services of augmented reality focused on markers/quick response codes, virtual items, global positioning system services as well as on platforms for game creation. The findings of the literature review are discussed in relation to research approaches that are needed for augmented reality games to be played either in formal or informal learning environments. © 2016 International Council for Educational Media