Search results for "Sor"
showing 10 items of 22772 documents
"Libero ed eloquente". La Vista alla Scuola di De Sanctis
2015
Analisi del rapporto tra parola e azione nella teoria del primo De Sanctis e nella personalità di Luigi La Vista. The essay focuses on the connection between the concepts of word and action in the thought of jung De Sanctis and in that of his pupil, Luigi La Vista.
TripAdvisor reviews as a teaching tool in the Tourism Spanish Classroom
2021
RESUMEN: Este artículo tiene como objetivo señalar la importancia de incluir y aprovechar en el aula de español con fines profesionales (Efp) los nuevos materiales del ámbito del turismo que han surgido en los últimos años. El trabajo parte del análisis pragmalingüístico de un corpus de elaboración propia de comentarios negativos de TripAdvisor. Después se señalan sus posibilidades didácticas para su implementación en el aula de español del turismo. ABSTRACT: The purpose of this article is to point out the importance of including and taking advantage of the new materials in the field of tourism that have emerged in recent years in the Spanish classroom for professional purposes (Efp). The w…
Comparative theoretical study of the Ag–MgO (100) and (110) interfaces
1999
We have calculated the atomic and electronic structures of Ag–MgO(100) and (110) interfaces using a periodic (slab) model and an ab initio Hartree–Fock approach with a posteriori electron correlation corrections. The electronic structure information includes interatomic bond populations, effective charges, and multipole moments of ions. This information is analyzed in conjunction with the interface binding energy and the equilibrium distances for both interfaces for various coverages. There are significant differences between partly covered surfaces and surfaces with several layers of metal, and these can be understood in terms of electrostatics and the electron density changes. For complet…
Color Sensitive Response of Graphene/Graphene Quantum Dot Phototransistors
2019
We present the fabrication and characterization of all-carbon phototransistors made of graphene three terminal devices, coated with atomically precise graphene quantum dots (GQD). Chemically synthesized GQDs are the light absorbing materials, while the underlying chemical vapor deposition (CVD)-grown graphene layer acts as the charge transporting channel. We investigated three types of GQDs with different sizes and edge structures, having distinct and characteristic optical absorption in the UV–vis range. The photoresponsivity exceeds 106 A/W for vanishingly small incident power (<10–12 W), comparing well with state of the art sensitized graphene photodetectors. More importantly, the photor…
High-pressure characterization of multifunctional CrVO4
2020
[EN] The structural stability and physical properties of CrVO(4)under compression were studied by x-ray diffraction, Raman spectroscopy, optical absorption, resistivity measurements, andab initiocalculations up to 10 GPa. High-pressure x-ray diffraction and Raman measurements show that CrVO(4)undergoes a phase transition from the ambient pressure orthorhombic CrVO4-type structure (Cmcm space group, phase III) to the high-pressure monoclinic CrVO4-V phase, which is proposed to be isomorphic to the wolframite structure. Such a phase transition (CrVO4-type -> wolframite), driven by pressure, also was previously observed in indium vanadate. The crystal structure of both phases and the pressure …
“Sweet” ionic liquid gels: materials for sweetening of fuels
2018
The search for new materials to be used in desulfurisation (sweetening) of fuels is one of the main topics of current research. In this paper, we explored the possibility of using supramolecular gels obtained from the gelation of ionic liquid binary mixtures. Indeed, some ionic liquids are generally known as efficient extraction phases for desulfurisation of fuels. In rare cases, one of their main drawbacks is their partial solubility in the fuel, leading to contamination. Then, their immobilisation due to the formation of a gelatinous network may be a challenge. Ionic liquid gels were obtained by mixing certain [NTf2]−-based ionic liquids (solvents) with the ones of gluconate-based ionic l…
Energy transfer in LH2 of Rhodospirillum Molischianum, studied by subpicosecond spectroscopy and configuration interaction exciton calculations.
2001
Two color transient absorption measurements were performed on a LH2 complex from Rhodospirillum molischianum by using several excitation wavelengths (790, 800, 810, and 830 nm) and probing in the spectral region from 790 to 870 nm at room temperature. The observed energy transfer time of ∼1.0 ps from B800 to B850 at room temperature is longer than the corresponding rates in Rhodopseudomonas acidophila and Rhodobacter sphaeroides. We observed variations (0.9-1.2 ps) of B800-850 energy transfer times at different B800 excitation wavelengths, the fastest time (0.9 ps) was obtained with 800 nm excitation. At 830 nm excitation the energy transfer to the B850 ring takes place within 0.5 ps. The m…
Random Tensor Theory: Extending Random Matrix Theory to Mixtures of Random Product States
2012
We consider a problem in random matrix theory that is inspired by quantum information theory: determining the largest eigenvalue of a sum of p random product states in $${(\mathbb {C}^d)^{\otimes k}}$$ , where k and p/d k are fixed while d → ∞. When k = 1, the Marcenko-Pastur law determines (up to small corrections) not only the largest eigenvalue ( $${(1+\sqrt{p/d^k})^2}$$ ) but the smallest eigenvalue $${(\min(0,1-\sqrt{p/d^k})^2)}$$ and the spectral density in between. We use the method of moments to show that for k > 1 the largest eigenvalue is still approximately $${(1+\sqrt{p/d^k})^2}$$ and the spectral density approaches that of the Marcenko-Pastur law, generalizing the random matrix…
Determination of an empirical law of aluminium and magnesium alloys absorption coefficient during Nd :YAG laser interaction
2007
International audience; Welding laser modelling requires knowledge about relative changes of many thermo-physical parameters involved in the interaction. The absorptivity of the material is one of the most important. In this study, experimental measurements of absorptivity with an integrating sphere on two alloys (aluminium and magnesium) were made. These results were compared with an analytical calculation that takes into account the trapping of the beam by multiple reflections inside the keyhole. Based on a statistical method, an empirical law is proposed connecting absorptivity with the peak power of the laser and the duration of interaction. During the interaction, two distinct phenomen…
Generalised bisection method for optimum ultrasonic ray tracing and focusing in multi-layered structures
2021
Ultrasonic testing has been used for many decades, proving itself very efficient for detecting defects in many industrial sectors. The desire to apply ultrasonic testing to geometrically complex structures, and to anisotropic, inhomogeneous materials, together with the advent of more powerful electronics and software, is constantly pushing the applicability of ultrasonic waves to their limits. General ray tracing models, suitable for calculating the proper incident angle of single element probes and the proper time delay of phased array, are currently required. They can support the development of new imaging techniques, as Full Matrix Capture and Total Focusing Method, and the execution of …