Search results for "VIT"

Ternary transition metals sulfides in hydrotreating catalysis.

2007

International audience; Pure microcrystalline barium molybdate BaMoO4 and barium tungstate BaWO4 materials were prepared by molten flux reaction using alkali metal nitrates as reaction media. The obtained crystals have rhombic shape and expose mostly (111) crystallographic planes. Their mean size depends on the flux temperature and the nature of the alkali metal cation. Monomeric molybdate and tungstate used as precursors yield target products already at 673 K whereas if polymerized ammonium oxosalts were used, then higher temperatures were necessary to obtain barium salts. The optimal temperature for the preparation of pure crystals with well defined shape was found to be near 773 K. UV–vi…

Relative $n$-isoclinism classes and relative nilpotency degree of finite groups

2013

The impact of visual working memory capacity on the filtering efficiency of emotional face distractors.

2018

Emotional faces can serve as distractors for visual working memory (VWM) tasks. An event-related potential called contralateral delay activity (CDA) can measure the filtering efficiency of face distractors. Previous studies have investigated the influence of VWM capacity on filtering efficiency of simple neutral distractors but not of face distractors. We measured the CDA indicative of emotional face filtering during a VWM task related to facial identity. VWM capacity was measured in a separate colour change detection task, and participants were divided to high- and low-capacity groups. The high-capacity group was able to filter out distractors similarly irrespective of its facial emotion. …

Phosphorous doping and drawing effects on the Raman spectroscopic properties of O=P bond in silica-based fiber and preform.

2012

International audience; We report an experimental study of the doping and drawing effects on the Raman activities of phosphorus (P)-doped silica-based optical fiber and its related preform. Our data reveal a high sensitivity level in the full width at half maximum value of the 1330 cm−1 (O = P) Raman band to the P-doping level. Its increase with the P doping level does not clash with an increase in the disorder of the O = P surrendering matrix. In addition, we observe that in the central core region of the sample (higher doping level), the drawing process decreases the relative band amplitude. We tentatively suggest that this phenomenon is due to the change in the first derivate of the bond…

Chemical Composition and Biological Activities of Prangos ferulacea Essential Oils

2022

Prangos ferulacea (L.) Lindl, which belongs to the Apiaceae family, is a species that mainly grows in the eastern Mediterranean region and in western Asia. It has been largely used in traditional medicine in several countries and it has been shown to possess several interesting biological properties. With the aim to provide new insights into the phytochemistry and pharmacology of this species, the essential oils of flowers and leaves from a local accession that grows in Sicily (Italy) and has not yet been previously studied were investigated. The chemical composition of both oils, obtained by hydrodistillation from the leaves and flowers, was evaluated by GC-MS. This analysis allowed us to …

Magneto Gravitational Modes Driven by the Modulated Gravitational Field of Compact Collapsing Binaries*

2019

A new theoretical process [1], to create high energy particle populations during the collapse of neutron star - neutron star or black hole - black hole binaries, has been identified. The oscillatory gravitational potential that is associated with the rotating binary is characterized by two frequencies, in the case where the masses of the two components are not equal, that reduce to one (the main) when the two masses are equal. Consequently the gravitationally confined plasma surrounding the considered binary will oscillate with the same frequencies. When one of these (e.g. the main) will become about equal to the frequency (about that of the compressional Alfvén wave) of a newly identified …

Vacancy-like Dressed States in Topological Waveguide QED

2020

We identify a class of dressed atom-photon states formingat the same energy of the atom at any coupling strength. As a hallmark, their photonic component is an eigenstate of the bare photonic bath with a vacancy in place of the atom. The picture accommodates waveguide-QED phenomena where atoms behave as perfect mirrors, connecting in particular dressed bound states (BS) in the continuum or BIC with geometrically-confined photonic modes. When applied to photonic lattices, the framework provides a general criterion to predict dressed BS in lattices with topological properties by putting them in one-to-one correspondence with photonic BS. New classes of dressed BS are thus predicted in the pho…

Colloquium: Nonequilibrium effects in superconductors with a spin-splitting field

2018

This Colloquium discusses the recent progress in understanding the properties of spin-split superconductors under nonequilibrium conditions. Recent experiments and theories demonstrate a rich variety of transport phenomena occurring in devices based on such materials that suggest direct applications in thermoelectricity, low-dissipative spintronics, radiation detection, and sensing. This text discusses different experimental situations and presents a theoretical framework based on quantum kinetic equations. This framework provides an accurate description of the nonequilibrium distribution of charge, spin, and energy, which are the relevant nonequilibrium modes, in different hybrid structure…

Superconducting size effect in thin films under electric field: Mean-field self-consistent model

2019

We consider effects of an externally applied electrostatic field on superconductivity, self-consistently within a BCS mean field model, for a clean 3D metal thin film. The electrostatic change in superconducting condensation energy scales as $\mu^{-1}$ close to subband edges as a function of the Fermi energy $\mu$, and follows 3D scaling $\mu^{-2}$ away from them. We discuss nonlinearities beyond gate effect, and contrast results to recent experiments.

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…