861 research outputs found
Overview on Classification of Flame-Retardant Additives for Polymeric Matrix
No full textPlastic additives are among the most relevant assets in the polymer industry for improving the properties of polymeric materials. The improvement of flame resistance is a major issue for the safe use of plastics for industrial and civilian purposes. For this reason, flame-retardant (FR) additives represent a very relevant class of compounds that are gaining further importance year by year. In this chapter, we report a general overview of the main FR additives, focusing on their action mechanisms together with the most significant achievements reported in the literature. We aim to provide a comprehensive description of the wide realm of FR additives that will represent a reference point for newcomers and a guide for experts in the field
Recent Advances in Biochar Polymer Composites
No full text“Biochar” (BC) is the solid residue recovered from the thermal cracking of biomasses in an oxygen-poor atmosphere. Recently, BC has been increasingly explored as a sustainable, inexpensive, and viable alternative to traditional carbonaceous fillers for the development of polymer-based composites. In fact, BC exhibits high thermal stability, high surface area, and electrical conductivity; moreover, its main properties can be properly tuned by controlling the conditions of the production process. Due to its intriguing characteristics, BC is currently in competition with high-performing fillers in the formulation of multi-functional polymer-based composites, inducing both high mechanical and electrical properties. Moreover, BC can be derived from a huge variety of biomass sources, including post-consumer agricultural wastes, hence providing an interesting opportunity toward a “zero waste” circular bioeconomy. This work aims at providing a comprehensive overview of the main achievements obtained by combining BC with several thermoplastic and thermosetting matrices. In particular, the effect of the introduction of BC on the overall performance of different polymer matrices will be critically reviewed, highlighting the influence of differently synthesized BC on the final performance and behavior of the resulting composites. Lastly, a comparative perspective on BC with other carbonaceous fillers will be also provided
Phytic acid and biochar: an effective all bio-sourced flame retardant formulation for cotton fabrics
No full textFlame retardant systems based on bio-sourced products combine quite high fire performances with the low environmental impact related to their synthesis and exploitation. In this context, this work describes a new all bio-sourced flame retardant system designed and applied to cotton fabrics. In particular, it consists of phytic acid (PA), a phosphorus-based naturally occurring molecule extracted from dierent plant tissues, in combination with biochar (BC), a carbon-rich solid product obtained from the thermo-chemical conversion of biomasses in an oxygen-limited environment. PA and BC were mixed together at a 1:1 weight ratio in an aqueous medium, and applied to cotton at dierent loadings. As revealed by flammability and forced combustion tests, this bio-sourced system was able to provide significant improvements in flame retardance of cotton, even limiting the final dry add-on on the treated fabrics at 8 wt.% only. The so-treated fabrics were
capable to achieve self-extinction in both horizontal and vertical flame spread tests; besides, they did not ignite under the exposure to 35 kW/m2 irradiative heat flux. Conversely, the proposed flame retardant treatment did not show a high washing fastness, though the washed flame retarded fabrics still exhibited a better flame retardant behavior than untreated cotton
Fine morphology of the myrmecophilous larva of Paussus kannegieteri (Coleoptera: Carabidae: Paussinae: Paussini). Corresponding author
No full textFIGURES 13–18. Paussus kannegieteri third instar larva: 13, thorax, left lateral view; 14, thorax, dorsal view; 15, mesothoracic spiracle; 16, metathoracic spiracle-like structure; 17, mesothoracic leg, anterolateral view; 18, apex of metathoracic leg with lanceolate setae, posterolateral view. CO = coxa, ls = lanceolate setae, m = membrane, ME = mesonotum, MT = metanotum, pe = peritreme, PR = pronotum, un = claw. Scale bars: Figs. 13–14 = 500 µm; Fig. 15 = 10 µm; Fig. 16 = 20 µm; Fig. 17 = 200 µm; Fig. 18 = 50 µm.Published as part of Giulio, Andrea Di, 2008, Fine morphology of the myrmecophilous larva of Paussus kannegieteri (Coleoptera: Carabidae: Paussinae: Paussini), pp. 37-50 in Zootaxa 1741 on page 44, DOI: 10.5281/zenodo.18152
Structure–Property Relationships in Polyethylene-Based Composites Filled with Biochar Derived from Waste Coffee Grounds
No full textIn this work, biochar (BC) derived from spent coffee grounds has been incorporated into high density polyethylene (PE) through melt mixing. The influence of the filler content on the rheological and thermal behavior of the obtained composites was assessed. In particular, a rheological study was performed systematically using different flow fields, including linear and nonlinear dynamic shear flow, revealing that the dynamics of PE macromolecules in the composite materials are slowed down because of the confinement of the polymer chains onto the filler surface and/or within the BC porous structure. Oscillatory amplitude sweep tests indicated that composites show weak strain overshoot behavior in the nonlinear regime: This finding clearly proves the formation of weak structural complexes, which cause a retardation of the macromolecular chains dynamics. Furthermore, the embedded BC particles were able to improve the thermo-oxidative stability of PE-based composites, remarkably increasing the PE decomposition temperatures
GIULIO TARRA TRADUTTORE DAL FRANCESE
No full textCon Il Libro pel bambino, Don Giulio Tarra risultò il vincitore di due concorsi indetti dal Congresso Pedagogico Italiano nel 1861: quello per un libro di lettura destinato ai bambini sordomuti e l’altro per un libro destinato alle scuole rurali. Fra le opere del Tarra pubblicate da Paolo Carrara è menzionato il volumetto “Lezioni in famiglia, versione da M. Carraud”. Questo contributo intende offrire alcuni elementi d’informazione su Zulma Carraud, autrice delle Historiettes véritables pour les enfants de quatre à huit ans, titolo originale della raccolta di racconti tradotta da Don Giulio. Il libro era uscito a Parigi nel 1864 per i tipi di Hachette. In precedenza lo stesso editore aveva accolto le prime opere di Zulma nelle collane destinate alla scuola primaria. A pochi anni di distanza l’uno dall’altra, la Carraud nella Francia del II Impero e il Tarra nell’Italia postunitaria, entrambi hanno contribuito con i loro “libri di lettura” allo sviluppo dell’editoria per la scuola e per l’infanzia.
Giulio Tarra translator from French
With the volume entitled Il Libro pel bambino, Don Giulio Tarra won two literary competitions held in 1861 by the Congresso Pedagogico Italiano: the first was dedicated to books for deaf-mute chidren, the second to books for rural schools. Among Tarra’s works published by Paolo Carrara we find “Lezioni in famiglia, versione da M. Carraud”. This article provides some information about Zulma Carraud, the author of the collection of novels entitled: Historiettes véritables pour les enfants de quatre à huit ans published by Hachette in 1864 and translated into Italian by Don Giulio. Previously the same publisher had collected Zulma’s first works in a series to be used in primary schools. Carraud, during the Second Empire period in France, and Tarra, in post-Unity Italy, both contributed to the development of the publishing industry for schools and children with their educational and entertaining books
Effect of the ingestion in the WRF model of different Sentinel-derived and GNSS-derived products: analysis of the forecasts of a high impact weather event
No full textThis paper presents the first experimental results of a study on the ingestion in the Weather Research and Forecasting (WRF) model, of Sentinel satellites and Global Navigation Satellite Systems (GNSS) derived products. The experiments concern a flash-floodevent occurred in Tuscany (Central Italy) in September 2017. The rationale is that numerical weather prediction (NWP) models are presently able to produce forecasts with a km scale spatial resolution, but the poor knowledge of the initial state of the atmosphere may imply an inaccurate simulation of the weather phenomena. Hence, to fully exploit the advances in numerical weather modelling, it is necessary to feed them with high spatiotemporal resolution information over the surface boundary and the atmospheric column. In this context, the Copernicus Sentinel satellites represent an important source of data, because they can provide a set of high-resolution observations of physical variables (e.g. soil moisture, land/sea surface temperature, wind speed) used in NWP models runs. The possible availability of a spatially dense network of GNSS stations is also exploited to assimilate water vapour content. Results show that the assimilation of Sentinel-1 derived wind field and GNSS-derivedwater vapour data produce the most positive effects on the performance of the forecast
TWIGA project activities for the enhancement of heavy rainfall predictions in Africa: low-cost GNSS network deployment and NWP model parameterization
No full textPreparation and characterization of UV-LED curable acrylic films containing biochar and/or multiwalled carbon nanotubes: effect of the filler loading on the rheological, thermal and optical properties.
No full textUV-LED curable coatings represent an up-to-date attractive field due to the high curing eciency even in the presence of high filler loadings, as well as to the absence of infrared wavelengths that may negatively impact on heat-sensitive substrates. The addition of carbonaceous materials, such as biochar (BC) and/or multiwalled carbon nanotubes (MWCNTs) could positively improve both the rheological and thermal properties. In this study we report on the synthesis and characterization of carbon-reinforced films containing nanometric (MWCNTs) and micrometric (BC) carbon-based
materials. We analyze the rheological properties of the UV-LED curable dispersions, as well as the thermal and optical properties of the resulting films, establishing some correlations between filler dispersion/loading with the main observed properties
Barocco italiano; Giovan Battista Basile
No full textSi tratta di due capitoli del volume Letteratura curato da Giulio Ferroni, in cui si definiscono le coordinate del Barocco in una chiave originale e si rivede l'opera del Basile, considerando non soltanto il Cunto de li Cunti, ma anche le opere volgari.These are two chapters of the volume titled Letteratura, ed. by Giulio Ferroni; the first is dedicated to a reassessment of the concept of Baroque in a new perspective; the second is a little monograph about the author of Lo Cunto de li Cunti, considering also his literary production in italian language
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