Prediction of the slope discontinuity in stress-strain behaviour of polymeric composites with spherical inclusions

The estimation of the point of discontinuity in the slope of stress-strain curves (commonly referred to as "knee") generally observed with composite polymeric materials could be an important problem for the specific application of the composite items. In this work, we have used the results from classical elasticity theory to calculate the residual thermal stresses and proposed simplifying assumptions to calculate a "lower bound" on the applied stress value at which the "knee" can occur. The theoretical predictions have been then compared with the experimental data on various polymeric composites containing glass beads and the agreement is found to be very sound. The proposed equation can be reliably used in engineering design

A Method for Simple and Precise Measurements of Kinetics of Reactions between SiC and Molten Al

Reinforced aluminum is generally fabricated by liquid metal infiltration. The reinforcement degradation produced by molten matrix is the major problem to be considered. The relationship between conversion and thermal exposure time is an important information. In the present paper a method for measuring the conversion by weight determinations is proposed

Wettability of Copper Coated Carbon Fibers

The wetting kinetics of a solid surface by a molten metal decrease with increase of its roughness. The topography of the growing copper coating, produced on carbon fiber surface by electroplating from a sulphat bath, has been studied by scanning electron microscopy. The smoothes surface is produced after 200÷300 milliampere-hour of plating

Connectivity-, Wiener- and Harary-Type Indices of Dendrimers

Formulas for calculating connectivity-based indices (Randić-type index calculated on vertices, χ, and on edges, ε, Zagreb index, M2, and Bertz index, B ) and distance-based indices (Wiener , W, hyper-Wiener, WW, and Harary-type indices, HWe and HWp) in regular homogeneous dendrimers are derived. Values of the above topological indices for families of dendrimers, with up to 10 orbits, are calculated. Mutual intercorrelation of these indices, in the considered dendrimers, is evaluated

A portable X-ray fluorescence device for in situ analyses of mural paintings

Within the context of a research program for studying with nondestructive methods the preparation and realisation techniques of mural paintings used in the Roman age, a portable ED-XRF device for elemental analysis has been set up. Preliminary tests have been carried out on two Roman mural paintings belonging to the Baia Archaeological Complex (Naples). Datable to different periods, the two paintings show different manufacturing and conservation states, thus representing a good test for verifying the ED-XRF device capability. In situ and laboratory measurements, performed on materials of different origin and nature, have permitted the determination of the pigments and the recognition of pollution traces

A portable X-ray fluorescence device for in situ analyses of mural paintings

Within the context of a research program for studying with nondestructive methods the preparation and realisation techniques of mural paintings used in the Roman age, a portable ED-XRF device for elemental analysis has been set up. Preliminary tests have been carried out on two Roman mural paintings belonging to the Baia Archaeological Complex (Naples). Datable to different periods, the two paintings show different manufacturing and conservation states, thus representing a good test for verifying the ED-XRF device capability. In situ and laboratory measurements, performed on materials of different origin and nature, have permitted the determination of the pigments and the recognition of pollution traces

Neural processing of emotions in traumatized children treated with eye movement desensitization and reprocessing therapy: a hdEEG study

Eye Movement Desensitization and Reprocessing (EMDR) therapy has been proven efficacious in restoring affective regulation in Post-Traumatic Stress Disorder (PTSD) patients. However, its effectiveness on emotion processing in children with complex trauma has yet to be explored. High density Electroencephalography (hdEEG) was used to investigate the effects of EMDR on brain responses to adults\u27 emotions on children with histories of early maltreatment. Ten school-aged children were examined before (T0) and within one month after the conclusion of EMDR (T1). hdEEGs were recorded while children passively viewed angry, afraid, happy, and neutral faces. Clinical scales were administered at the same time. Correlation analyses were performed to detect brain regions whose activity was linked to children\u27s traumatic symptom-related and emotional-adaptive problem scores. In all four conditions, hdEEG showed similar significantly higher activity on the right medial prefrontal and fronto-temporal limbic regions at T0, shifting towards the left medial and superior temporal regions at T1. Moreover, significant correlations were found between clinical scales and the same regions whose activity significantly differed between pre- and post-treatment. These preliminary results demonstrate that, after EMDR, children suffering from complex trauma show increased activity in areas implicated in high-order cognitive processing when passively viewing pictures of emotional expressions. These changes are associated with the decrease of depressive and traumatic symptoms, and with the improvement of emotional-adaptive functioning over time

Theoretical Insights into Vinyl Derivatives Adsorption on a Cu(100) Surface

This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.8b06142Here, we present a thorough theoretical study of the adsorption of acrolein (ACO), acrylonitrile (ACN), and acrylamide (ACA) on Cu(100) surface. For this purpose, we have used the density functional theory, imposing periodic boundary conditions to have a correct description of the electronic band structure of the metal and including dispersion forces through two different schemes: the D2 method of Grimme and the vdW-DF. We have found several adsorption geometries. In all of them, the vinyl group together with the amide (in ACA), ciano (in ACN), and carbonyl (in ACO) groups, is highly involved. The highest adsorption energy is found for acrylamide, followed by acrolein and the lowest for acrylonitrile (depending on the level of theory employed ∼1.2, 1.0, and 0.9 eV, respectively). We show that a strong coupling between the π electronic system (both occupied and virtual orbitals) and the electronic levels of the metal is mainly responsible of the chemisorption. As a consequence, electronic density is transferred from the surface to the molecule, whose carbon atoms acquire a partial sp3 hybridization. Lone-pair orbitals of the cyano, amide, and carbonyl groups also play a role in the interaction. The simulations and following analysis allow to disentangle the nature of the interaction, which can be explained on the basis of a simple chemical picture: donation from the occupied lone pair and π orbitals of the molecule to the surface and backdonation from the surface to the π∗ orbital of the molecule (π-backbonding)This work was partially supported by the project CTQ2016-76061-P of the Spanish Ministerio de Economı́a y Competitividad (MINECO). F.A.G. acknowledges the FPI grant associated with the project CTQ2013-43698-P (MINECO). Financial support from the MINECO through the “Marı́a de Maeztu” Program for Units of Excellence in R&D (MDM-2014-0377) is also acknowledge