Search results for " Materiali"
showing 10 items of 710 documents
Polysaccharide nanocrystals as fillers for PLA based nanocomposites
2016
The development of green nanocomposites based on biopolymers and bio-based nanofillers has attracted over the recent years the attention of academic and industrial research. Indeed, these nanocomposites could replace some oil-derived polymers and thus helping to overcome environmental problems. In this regard, PLA as matrix and polysaccharide nanocrystals as fillers are the most promising components to obtain high-performance green bio-nanocomposites suitable for different applications, particularly for packaging and biomedical applications. Indeed, at present, due to its processability, mechanical and biological properties, as well as its commercial availability, poly(lactic acid) (PLA) po…
Effect of Sheep Wool Fibers on Thermal Insulation and Mechanical Properties of Cement-Based Composites
2019
The use of sheep wool as a filler of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, it is considered as a waste and, therefore, its use is characterized by low cost. The aim of this paper is to evaluate the influence of wool fibers on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibers, obtained from a breed of Sicilian sheep, with three different lengths (i.e., 1, 6, and 20 mm). Furthermore, in order to evaluate the influence of fiber content, the samples were prepared by varying the fiber weight fraction. The thermal conductivity of the samples was analyzed by using a heat flo…
Valorisation of industrial iron oxide waste to produce magnetic barium hexaferrite
2016
Barium M-type hexagonal ferrite (BaM, BaFe12O19) is an immensely important magnetic material, which we have successfully made from the simple valorisation of Fe-rich industrial waste from steel wire drawing, with addition of BaCO3 and heating in air to 1000 degrees C. The optimum ratio of Fe. Ba (producing 86 wt% BaM) was found to be 11: 1 (non-stoichiometric), and secondary phases of alpha-Fe2O3 (non-magnetic) and ZnFe2O4 (poorly antiferromagnetic) were always present. This material consisted of small submicron platelets. A hard magnetic ferrite was produced with Ms=48.6 A m(2) kg(-1) and H-c=211.5 kA m(-1). The highest density was achieved by sintering samples with Fe: Ba ratios of 11: 1 …
New Lignocellulosic Aristida adscensionis Fibers as Novel Reinforcement for Composite Materials: Extraction, Characterization and Weibull Distributio…
2019
In this research, the Aristida adscensionis fibers (AAFs) were taken out from the plants and its fundamental properties anlayzed for the first time. The AAFs were characterized and compared with other natural fibers by the use of physico-chemical analysis and various characterization techniques such as FT-IR, XRD, NMR, TGA, SEM and AFM. Chemical analysis showed that A. adscensionis fibers have a high cellulose content of 70.78% whereas the contents of lignin and wax are equal to 8.91% and 2.26%, respectively. The FT-IR, XRD and NMR analysis confirmed that AAFs are rich in cellulose content with CI and CS equal to 58.9% and 11.5 nm, respectively. Pycnometer analysis allowed to estimate a den…
La tradizione costruttiva degli edifici di culto in legno lituani tra XVIII e XIX secolo
2014
Lithuania is situated in a highly forested Northern Europe area and has a variety of wooden buildings. These buildings are still mostly prevalent in villages and towns as well as in large cities, intimately related with landscape and nature, most of which had been realized in 18th and 19th centuries. Among the wooden structures we enumerate the religious buildings, churches and bell towers, rich of historic values, presenting different forms and sizes, a complex design and stratified construction phases. The wooden buildings realized in the 18th century are rich of historical and stylistic references with the other European countries: in these churches we can find the perfect representative…
La hermenéutica materialista
2014
Adorno formula per la prima volta il programma della Teoria Critica come "ermeneutica materialista". Dopo la "svolta ermeneutica" della filosofia nella seconda metà del ventesimo secolo, questo saggio cerca di stabilire il profilo dell’ermeneutica di Adorno. Come una critica dell’idealismo semantico e di tutti gli idealismi, questa ermeneutica fissa un nuovo statuto per la filosofia dopo Hegel, in un dialogo critico con le scienze, con la "genealogia" di Nietzsche, con l’"inconscio" di Freud, e con un importante re-interpretazione dell’undicesima tesi su Feuerbach di Marx.
Carboxylated-xyloglucan and peptide amphiphile co-assembly in wound healing.
2021
Abstract Hydrogel wound dressings can play critical roles in wound healing protecting the wound from trauma or contamination and providing an ideal environment to support the growth of endogenous cells and promote wound closure. This work presents a self-assembling hydrogel dressing that can assist the wound repair process mimicking the hierarchical structure of skin extracellular matrix. To this aim, the co-assembly behaviour of a carboxylated variant of xyloglucan (CXG) with a peptide amphiphile (PA-H3) has been investigated to generate hierarchical constructs with tuneable molecular composition, structure, and properties. Transmission electron microscopy and circular dichroism at a low c…
The durability of basalt fibres reinforced polymer (BFRP) panels for cladding
2015
The study focuses on two basalt composite laminate panels for cladding, produced by means of vacuum bagging technique. In particular, unidirectional and random basalt fabrics, with different areal weights, using epoxy resin as matrix, were used. According to the ISO 15686 methodology for the evaluation of durability, samples were subjected to cycles of artificial aging in climatic chamber and outdoor exposure, carrying out mechanical (i.e. quasi-static and dynamic) and calorimetric tests. The results show the effectiveness over time of produced basalt composite laminates and the initial increase of the mechanical performances after the first steps of accelerated aging.
Using Taguchi method for the optimization of processing variables to prepare porous scaffolds by combined melt mixing/particulate leaching
2017
Synthetic biopolymers have made significant inroads into the development of devices for tissue regeneration. In this context, a challenge is the achievement of appropriate properties mimicking the natural extracellular matrix by fabricating scaffolds presenting mechanical properties, specific surface, porosity and pore interconnection adequate for the final application. This study involved a systematic procedure based on Taguchi method for parameters optimization of melt mixing/particulate leaching combined processes aiming to enhance the performance of the scaffolds. In particular, it was evaluated the effect of time and temperature of melt mixing of the poly(lactic acid) matrix with two w…
Microwave response properties of epoxy resin composites filled with graphitic fillers
2014
Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite (EG), natural graphite, and coarse, medium and fine artificial graphites have been prepared. The dielectric permittivity strongly increases with graphite particle size. This effect is related to the distance of the investigated filler concentrations to the composites' percolation threshold. Microwave experiments show that exfoliated graphite is, out of investigated graphite particles, the only one being a really effective additive for producing electromagnetic (EM) interference (EMI) shielding: 2 wt.% epoxy/EG is absolutely opaque to electromagnetic radiation at 30 GHz.