Search results for " Composite"
showing 10 items of 1884 documents
Electrochemical Fingerprint of Archeological Lead Silicate Glasses Using the Voltammetry of Microparticles Approach
2016
9 págs.; 14 figs.; 1 tab.
Efficient ultraviolet-light energy dissipation by an aromatic ketone.
2010
Experimental evidence on the efficiency of 2,2'4,4'-tetramethoxybenzil for UV-light energy dissipation is provided. This non-phenolic aromatic ketone has a low energy triplet which quickly decays to the ketone ground state, thus avoiding the generation of undesirable reactive species. El Moncef, Abdelkarim, elmonab@alumni.uv.es ; Cuquerella Alabort, Maria Consuelo, Chelo.Cuquerella@uv.es ; Zaballos Garcia, Elena, Elena.Zaballos@uv.es ; Ramirez de Arellano Sanchez, Maria del Carmen, Carmen.Ramirezdearellano@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es
Modeling of Point Defects in Corundum Crystals
1994
Several different approaches including Hartree-Fock ab initio cluster calculations, semiempirical INDO calculations, and atom-atom potentials were used for modeling of the spatial and electronic structure as well as migration mechanisms of both intrinsic defects (self-trapped and defect-trapped holes, O and Al vacancies) and impurities (transition-metal ions like Co, Fe, Mg, Mn, Ti). The atomic structure of all hole centers is found to be similar to V[sub K] centers in alkali halides (two-site model); their formation is energetically favorable. The energy required for 60[degree] hole reorientations inside the basic oxygen triangles is found to be similar to both the energy for hops between …
Dipolar and orientational glass formation in two-dimensional films of CO mixtures
2002
Heat-capacity and dielectric measurements have been performed to study orientational and dipolar order and disorder phenomena in submonolayer films of CO and binary mixtures of CO physisorbed on graphite and boron nitride (BN). With both methods transitions to quadrupolar and dipolar ordered low-temperature phases have been found for pure CO. Calorimetric measurements revealed that the dipolar transition of CO on graphite belongs to the universality class of the two-dimensional (2D) Ising model. It will be shown that in dilute mixtures of CO with CH 4 molecules a dramatic suppression of this phase transition occurs. This effect turned out to be much stronger than that previously observed in…
Temperature dependance of the generation and decay of E’ centers induced in silica by 4.7eV laser radiation
2009
We report a study of the generation of silicon dangling bonds (E' centers) induced in fused silica by 4.7 eV laser irradiation in the 10 200 K the induced defects undergo a post-irradiation decay due to their reaction with mobile H(2). The interplay between generation and annealing gives rise to a bell-shaped temperature dependence of the concentration of induced E' centers, peaking at 250 K
Structural Health Monitoring Procedure for Composite Structures through the use of Artifcial Neural Networks
2015
In this paper different architectures of Artifcial Neural Networks (ANNs) for structural damage detection are studied. The main objective is to investigate an ANN able to detect and localize damage without any prior knowledge on its characteristics so as to serve as a real-time data processor for Structural Health Monitoring (SHM) systems. Two different architectures are studied: the standard feed-forward Multi Layer Perceptron (MLP) and the Radial Basis Function (RBF) ANNs. The training data are given, in terms of a Damage Index =D, properly defined using a piezoelectric sensor signal output to obtain suitable information on the damage position and dimensions. The electromechanical respons…
On the use of artificial intelligence tools for fracture forecast in cold forming operations
2006
Abstract The design of cold forming processes requires the availability of a procedure able to deal with the prevention of ductile fracture. In fact, the ability to predict fracture represents a powerful tool to improve the production quality in mechanical industry. In this paper, artificial intelligence (AI) techniques are applied to ductile fracture prediction in cold forming operations. The main advantage of the application of AI tools and in particular, of artificial neural networks (ANN), is the possibility to obtain a predictive tool with a wide applicability. The prediction results obtained in this paper fully demonstrate the usefulness of the proposed approach.
Arundo Donax particles as reinforcement for PLA based composites
2015
Aim of this work was to use particles obtained by grinding the culms of Arundo Donax used as reinforcement for PLA based composites. The influence of the content (10 wt% and 20 wt%) and size (150-300 μm and 300-500 μm) of Arundo Donax filler (ADF) on the morphology and on the properties of PLA-ADF composites was evaluated. The composites were prepared by melt compounding the PLA with ADF using a co-rotating modular twin screw extruder. For comparison, neat PLA was processed under the same conditions. Both the neat PLA and the composites were characterized by SEM, DSC, tensile and flexural measurements.
Multitemporal Mosaicing for Sentinel-3/FLEX Derived Level-2 Product Composites
2020
The increasing availability of remote sensing data raises important challenges in terms of operational data provision and spatial coverage for conducting global studies and analyses. In this regard, existing multitemporal mosaicing techniques are generally limited to producing spectral image composites without considering the particular features of higher-level biophysical and other derived products, such as those provided by the Sentinel-3 (S3) and Fluorescence Explorer (FLEX) tandem missions. To relieve these limitations, this article proposes a novel multitemporal mosaicing algorithm specially designed for operational S3-derived products and also studies its applicability within the FLEX…
Aurophilicity as a cofactor in crystal engineering. Dicyanoaurate(I) anion as a building block in a novel Co(II)–Au(I) bimetallic assembly
2002
A 2D grid-shaped cyanide-bridged Co(II)–Au(I) bimetallic coordination polymer, [Co(DMF)2{Au(CN)2}2], has been prepared from the [Au(CN)2]2 building block; sheets associate pair-wise by aurophilic interactions and the compound exhibits zeolite-like properties. Lloret Pastor, Francisco, Francisco.Lloret@uv.es