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

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

Factors affecting quality and safety of fresh-cut produce

The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail