Search results for "composite"
showing 10 items of 4584 documents
Health-Improved Textiles Obtained by Heat Surface Ecodyeing Treatments
2015
The central idea of the present research aims at achieving textile substrates through an efficient inclusion of a wild black cherry extract into the grafting agent-monochlorotriazinyl-β-cyclodextrin (MCT-β-CD). The methodology consists in a permanent/irreversible entrapment onto the fibres surface of the natural extract through inclusion mechanism. Exhaustion and sonication dyeing procedures were used alternatively. The obtained materials were characterized, by FT-IR and BET analysis. The experimental results reveal good adsorptive feature of the samples, due to a higher specific surface created by the inclusion complex (MCT-β-CD-dye pigment). An efficient blocking of the natural dye pigmen…
Evaluation of dermal toxicity of antibacterial cotton textile coated by sol-gel technology
2017
AbstractThis paper reports about cotton textile modification by sol-gel technology with the purpose of obtaining antibacterial properties, evaluation of antibacterial properties and dermal toxicity tests of cotton textile with Zn and Si coating. Antibacterial properties evaluation against pathogenic microorganisms Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli made using the Parallel streak method in accordance with ATCC147 standard. For more specific evaluation of the coated textile, in vitro cytotoxicity test with epidermal HaCat cells was done. It is concluded that the coatings containing Zn and Si obtained by the sol-gel technology can impart antibacterial propertie…
Narrativa dei Caraibi nel nuovo millennio
2020
L’etichetta “Letterature franco-caraibica” utilizzata, per convenzione, dalla critica per indicare unitariamente la produzione letteraria in lingua francese della regione centrale del Continente americano è assai impropria. La regione dei Caraibi abbraccia, infatti, sia alcune delle isole dell’arcipelago delle Piccole Antille (Martinica, Guadalupa), sia l’isola di Haïti, che fa parte delle Grandi Antille, che la Guiana incastonata sulla costa orientale dell’America meridionale. Pur nella diversità dei movimenti ideologici e degli avvenimenti storici che si sono succeduti nella regione, le opere letterarie degli scrittori caraibici francofoni, nel loro insieme, hanno oscillato, e continuano …
Caraibi: un "archipel inachevé"
2018
L’etichetta “Letterature franco-caraibica” utilizzata, per convenzione, dalla critica per indicare unitariamente la produzione letteraria in lingua francese della regione centrale del Continente americano è assai impropria. La regione dei Caraibi abbraccia, infatti, sia alcune delle isole dell’arcipelago delle Piccole Antille (Martinica, Guadalupa), sia l’isola di Haïti, che fa parte delle Grandi Antille, che la Guiana incastonata sulla costa orientale dell’America meridionale. Pur nella diversità dei movimenti ideologici e degli avvenimenti storici che si sono succeduti nella regione, le opere letterarie degli scrittori caraibici francofoni, nel loro insieme, hanno oscillato, e continuano …
Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids
2014
Multiple Crack Localization and Debonding Mechanisms for Thin Thermal Coating Films
2020
Experimental tests, carried out on small scale alloy specimens covered on one side with a thin thermal coating, have shown complex failure mechanisms. The failure mechanisms observed are due to the competition between two fracture mechanisms. The two mechanisms are: (i) Vertical tensile coating surface cracks and (ii) debonding shear decohesion mechanisms along the interface between the coating and the substrate. The present paper analyzes the mechanical problem of the nonlinear behavior thin film on a stiff substrate adopting a computational approach. Namely, incremental 2D nonlinear finite element simulations. The stiff superalloy substrate is modeled as a thermo-elastic material. The coa…
Dependence of thermal conductivity on structural parameters in porous samples
2012
The in-plane thermal conductivity of porous sintered bronze plates was studied both experimentally and numerically. We developed and validated an experimental setup, where the sample was placed in vacuum and heated while its time-dependent temperature field was measured with an infrared camera. The porosity and detailed three-dimensional structure of the samples were determined by X-ray microtomography. Lattice-Boltzmann simulations of thermal conductivity in the tomographic reconstructions of the samples were used to correct the contact area between bronze particles as determined by image analysis from the tomographic reconstructions. Small openings in the apparent contacts could not be de…
Biomass-based composite catalysts for catalytic wet peroxide oxidation of bisphenol A : preparation and characterization studies
2019
Abstract The wet granulation process was used to prepare new, efficient, and cost-effective granular biomass-based composite catalysts for catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA). The most stable composite granules was prepared by mixing biomass-based carbon residue (CR) with metakaolin (MK) combined with calcium oxide (CaO) or cement and a solvent (NaOH or KOH). For all the prepared composite granules, the optimized binding agents to carbon ratio was 0.3, the solvent to carbon ratio 1.2, and the agitation rate 1200 rpm. The specific surface area of the prepared catalysts was 152–205 m2/g. The composite granular catalyst (CR + MK + CaO + NaOH) had the most durable and s…
Active colloidal suspensions: Clustering and phase behavior
2014
We review recent experimental, numerical, and analytical results on active suspensions of self-propelled colloidal beads moving in (quasi) two dimensions. Active colloids form part of the larger theme of active matter, which is noted for the emergence of collective dynamic phenomena away from thermal equilibrium. Both in experiments and computer simulations, a separation into dense aggregates, i.e., clusters, and a dilute gas phase has been reported even when attractive interactions and an alignment mechanism are absent. Here, we describe three experimental setups, discuss the different propelling mechanisms, and summarize the evidence for phase separation. We then compare experimental obse…
Aging effects in simple models for glassy relaxation
2006
Aging effects in the two-time correlation function and the response function after a quench from a high temperature to some low temperature are considered for a simple kinetic random energy model exhibiting stretched exponential relaxation. Because the system reaches thermal equilibrium for long times after the quench, all aging effect are of a transient nature. In particular, the violations of the fluctuation-dissipation theorem are considered and it is found that the relation between the response and the two-time correlation function depends on another function, the so-called asymmetry. This asymmetry vanishes in equilibrium but cannot be neglected in the aging regime. It is found that pl…