Search results for "sites"
showing 10 items of 2851 documents
L'occupation humaine du Grand-Duché de Luxembourg à l'âge du Bronze Final : inventaire des sites et bilan de l'état de la documentation
2017
International audience
Silica as a green exfoliant agent for graphene oxidepolymer nanocomposites prepared in the melt
2017
For the first time, solid-state exfoliant agents were used to hinder the re-aggregation of graphene oxide (GO) during melt processing with polyamide 6 (PA6). This technique drastically reduces the time and difficulty related to solvent (removal, disposal, etc.), and avoids water consumption, since in this case 150 mL of water under mild operative conditions are enough to prepare the amount of GOS necessary for the realization of almost 100 grams of PA6- GOS nanocomposites with outstanding ultimate properties.
Pulicaria glutinosa Extract: A Toolbox to Synthesize Highly Reduced Graphene Oxide-Silver Nanocomposites
2015
A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag) via simultaneous reduction of both graphene oxide (GRO) and silver ions using Pulicaria glutinosa plant extract (PE) as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG) which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs) on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The as-prepared PE-HRG-Ag nanocomposities display excellent surfac…
Fibre fragment distribution in a single-fibre composite tension test
2001
Abstract Single fibre fragmentation tests are performed for brittle fibres with Weibull strength distribution and different surface treatments. The fragmentation process is modelled and closed-form expressions for break spacing distribution are obtained. The model accounts for the effect of finite fibre length on the initial fragmentation as well as for break interaction on the advanced fragmentation stage. It is assumed that the exclusion zone due to fibre–matrix interface failure and stress recovery in the fibre is linearly dependent on the applied load. This assumption is validated experimentally. The derived theoretical average fragment length dependence on applied load is used to deter…
Estimation de la différence de température entre la forêt et les sites ouverts dans le Jura
2017
International audience; Cet article porte sur la modélisation statistique des différences qui apparaissent entre la température observée en forêt et en site ouvert. Pour ce faire, nous utilisons un corpus de 29 couples de stations situées à faible distance l'une de l'autre dans les deux milieux et localisés dans le Jura (France). Les températures minimales (tn) et maximales (tx) ont été acquises de décembre 2014 à octobre 2015. La modélisation est fondée sur un modèle de régression où les variables explicatives sont deux variables temporelles relatives aux conditions atmosphériques (amplitude journalière et écart à la normale 1981-2010 des températures). En moyenne, les tn sont plus élevés …
Refining the preconditions of a social licence to operate (SLO) : reflections on citizens’ attitudes towards mining in two Finnish regions
2016
The debate around the social licence to operate (SLO) has been lively in recent years. In its elementary forms, the SLO is interpreted as the social acceptance granted by a community to mineral exploration and mining activities. Our theoretical assumption is that the SLO as a concept is both case-specific and more general, contingent, among other things, upon public opinion. In this study, acceptance is considered as general and anticipatory in the sense that it can act as a precondition for individual SLOs. Our intention is to contribute especially to recent novel research focusing on the more general background and factors contributing to the SLO. Using survey data (N = 1064), we explore …
The social significance of the Facebook Like button
2015
In this paper we study social aspects of using the Like button for purposes of impression management, identity construction, and maintenance of social ties online. On the theoretical level our investigation combines Goffman’s notion of face-work with concepts of social network analysis, shedding light on what we dub ‘nano-level’ interaction and sociality on social networking sites. Our data come from a 2013 classroom survey in which 26 Finnish university students were asked about their motives for and ways of using the Like button. Our results show that though the Like button was designed to allow users to express their positive evaluations of the contents of Facebook posts, comments, and p…
Bi-2212 and Y123 highly curved single-crystal-like objects: whiskers, bows and ring-like structures
2012
High-temperature superconducting objects of Bi2Sr2CaCu2O8 and Y Ba2Cu3O7 highly curved in the ab-plane, such as curved/kinked whiskers, bows and ring-like structures, were obtained within a solid?liquid?solid (SLS) grass-like growth mechanism. As-grown objects are crystals with three-dimensional epitaxy similar to conventional single crystals: they can be viewed as crystal parts ?cut? from a conventional rectangular crystal. Between our curved objects and conventional crystals, whiskers or thin films there are some differences in the superconducting properties induced only by the shape factors and no new physics is observed. Some details of the growth mechanism are discussed, emphasizing cu…
Sonication-Induced Modification of Carbon Nanotubes: Effect on the Rheological and Thermo-Oxidative Behaviour of Polymer-Based Nanocomposites.
2018
The aim of this work is the investigation of the effect of ultrasound treatment on the structural characteristics of carbon nanotubes (CNTs) and the consequent influence that the shortening induced by sonication exerts on the morphology, rheological behaviour and thermo-oxidative resistance of ultra-high molecular weight polyethylene (UHMWPE)-based nanocomposites. First, CNTs have been subjected to sonication for different time intervals and the performed spectroscopic and morphological analyses reveal that a dramatic decrease of the CNT's original length occurs with increased sonication time. The reduction of the initial length of CNTs strongly affects the nanocomposite rheological behavio…