Search results for "ASIS"
showing 10 items of 4190 documents
Comparative Theoretical Analysis of BN Nanotubes Doped with Al, P, Ga, As, In, and Sb
2013
SUMMARY AND CONCLUDING REMARKS We have performed large-scale first-principles calculations ofthe electronic structure of (5,5) boron nitride nanotubescontaining the following substitutional impurity atoms: Al, P,Ga, As, In, and Sb. Calculations have been performed using thetwo methods: (i) linear combination of atomic orbitals(LCAO) with the atomic-centered Gaussian-type functions asa basis set and (ii) linearized augmented cylindrical wave(LACW) accompanied with the local density functional andmuffin-tin approximations for the electronic potential. In arelatively good qualitative agreement, both methods predict lowformation energies and, thus, relative stability of point defectsthat are assoc…
Custom measurement system for memristor characterisation
2021
Abstract A cheap, compact and customisable characterisation system for memristor devices, working between ± 10 V, is presented. SPICE (Simulation Program with Integrated Circuit Emphasis) simulations are performed to verify the circuit feasibility and a proper software is developed to drive the system. The potentiality of the realised system is tested by performing several electrical measurements on both Cu/HfO2/Pt memristors and two-terminals commercial devices.
Conic optical fiber probe for generation and characterization of microbubbles in liquids
2021
Abstract A novel optical fiber probe has been developed to provide mechanical stability to microbubbles generated in fluids, the tip of the fiber is etched with hydrofluoric acid to pierce a truncated horn that fastens the microbubbles to the fiber tip and prevents misalignment or detachment caused by convection currents, vibrations or shocks in the liquid. Microbubbles are photo-thermally generated on the etched fiber and used as Fabry-Perot cavity sensor. Two methods were used to interrogate the probe: the first one, in the wavelength domain, is suitable for calibration in static or quasi static situations; the second one, in the time domain, can be used in dynamic environments. Experimen…
Enabling partially reconfigurable IP cores parameterisation and integration using MARTE and IP-XACT
2012
International audience; This paper presents a framework which facilitates the parameterization and integration of IP cores into partially reconfigurable SoC platforms, departing from a high-level of abstraction. The approach is based in a Model-Driven Engineering (MDE) methodology, which exploits two widely used standards for Systems-on-Chip specification, MARTE and IP-XACT. The presented work deals with the deployment level of the MDE approach, in which the abstract components of the platform are first linked to the lower level IP-XACT counterparts. At this phase, information for parameterization and integration is readily available, and a synthesizable model can be obtained from the gener…
Quasi-static behaviour and damage assessment of flax/epoxy composites
2015
Experimental investigations were conducted on flax and E-glass fibres reinforced epoxy matrix composites subjected to quasi-static loadings. Flax/epoxy samples having [0]12, [90]12, [0/90]3S and [±45]3S stacking sequences, with a fibre volume fraction of 43% have been tested under tension, compression and in-plane shear loadings. Overall, the compression strength of glass/epoxy was 76% greater than for the flax/epoxy composite. The damage evolution of flax/epoxy of [0/90]3S and [±45]3S samples has been evaluated in terms of transverse crack densities with respect to the load increment. The crack density exhibited a classical “S” shaped pattern for [0/90]3S and linearly for [±45]3S specimens…
On the ‘expanded local mode’ approach applied to the methane molecule: isotopic substitution CH2D2←CH4
2011
On the basis of a compilation of the ‘expanded local mode’ model and the general isotopic substitution theory, sets of simple analytical relations between different spectroscopic parameters (harmonic frequencies, ωλ, anharmonic coefficients, x λμ, ro-vibrational coefficients, , different kinds of Fermi- and Coriolis-type interaction parameters) of the CH2D2 molecule are derived. All of them are expressed as simple functions of a few initial spectroscopic parameters of the mother, CH4, molecule. Test calculations with the derived isotopic relations show that, in spite of a total absence of initial information about the CH2D2 species, the numerical results of the calculations have a very good…
Coupled-Cluster study of ‘no-pair’ bonding in the tetrahedral Cu4 cluster
2011
Abstract Ab initio Coupled-Cluster calculations with single and double excitations and perturbative correction to the triple, CCSD(T), have been carried out for the high-spin electronic state, ( 5 A 2 ) , of the copper cluster Cu 4 in its tetrahedral arrangement. Like alkali metals clusters, tetrahedral Cu 4 presents a bound quintet state, i.e., a situation where all the valence electrons are unpaired. This rather exotic wavefunction, also known as no-pair bonding state, is examined in detail. The influence of the basis set is also analyzed, as well as the importance of the core correlation and the effect of the basis-set superposition errors.
Towards highly accurate ab initio thermochemistry of larger systems: benzene.
2011
The high accuracy extrapolated ab initio thermochemistry (HEAT) protocol is applied to compute the total atomization energy (TAE) and the heat of formation of benzene. Large-scale coupled-cluster calculations with more than 1500 basis functions and 42 correlated electrons as well as zero-point energies based on full cubic and (semi)diagonal quartic force fields obtained with the coupled-cluster singles and doubles with perturbative treatment of the triples method and atomic natural orbital (ANO) triple- and quadruple-zeta basis sets are presented. The performance of modifications to the HEAT scheme and the scaling properties of its contributions with respect to the system size are investiga…
Multiple vibrational resonances in the Raman spectra of liquid ethanes
1990
The Raman spectra of liquid ethane, ethane-d3 and ethane-d6 were recorded and analysed. The CH3 and CD3 stretching regions were computer resolved using Cauchy-Gaussian and Voigt functions to account for asymmetric band shapes. Multiple vibrational resonances were investigated using the wavenumbers and observed intensities in these regions. The developed basis functions show strong mixing of the levels in these regions. In general the resonances appear to be less strong in the liquid phase than reported in previous studies of the gaseous state. Some new assignments in the liquid-state spectra of ethanes could be suggested.
Multi-scale multireference configuration interaction calculations for large systems using localized orbitals: Partition in zones
2012
A new multireference configuration interaction method using localised orbitals is proposed, in which a molecular system is divided into regions of unequal importance. The advantage of dealing with local orbitals, i.e., the possibility to neglect long range interaction is enhanced. Indeed, while in the zone of the molecule where the important phenomena occur, the interaction cut off may be as small as necessary to get relevant results, in the most part of the system it can be taken rather large, so that results of good quality may be obtained at a lower cost. The method is tested on several systems. In one of them, the definition of the various regions is not based on topological considerati…