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Electron-scale shear instabilities: magnetic field generation and particle acce...

WOS:000333714500001 (Nº de Acesso Web of Science) ; Strong shear flow regions found in astrophysical jets are shown to be important dissipation regions, where the shear flow kinetic energy flow is converted into electric and magnetic field energy via shear instabilities. The emergence of these self-consistent fields makes shear flows significant sites for radiation emission and particle acceleration. We focus ...

dc-Magnetic-Field Generation in Unmagnetized Shear Flows

WOS:000321278300010 (Nº de Acesso Web of Science) ; The generation of dc magnetic fields in unmagnetized electron-ion shear flows is shown to be associated to either initial thermal effects or the onset of electron-scale shear instabilities, in particular the cold Kelvin-Helmholtz instability. This mechanism, intrinsic to shear gradients on the electron scale, is described through a kinetic model that predicts...

Blistering of W–Ta composites at different irradiation energies

Pure tungsten and tantalum plates and tungsten–tantalum composites produced via mechanical alloying and spark plasma sintering were bombarded with He+ and D+ energetic ion beams and deuterium plasmas. The aim of this experiment is to study the effects caused by individual helium and deuterium exposures and to evidence that the modifications induced in the composites at different irradiation energies could be fo...

Synergistic helium and deuterium blistering in tungsten–tantalum composites

Tungsten–tantalum composites with 10 and 20 at.% Ta were prepared by ball milling W powder with Ta fibers and by consolidating the milled materials with spark plasma sintering. The composites were implanted at room temperature with He+ (30 keV with a fluence 5 1021 at/m2) and/or D+ (15 keV with a fluence 5 x 1021 at/m2) ion beams. The materials were studied by scanning and high-resolution transmission electron ...

Effects of helium and deuterium irradiation on SPS sintered W–Ta composites at ...

Energetic He+ and D+ ions were implanted into different W–Ta composites in order to investigate their stability under helium and deuterium irradiation. The results were compared with morphological and chemical modifications arising from exposure of pure W and Ta. Special attention was given to tantalum hydride (Ta2H)formation due to its implications for tritium inventory. Three W–Ta composites with 10 and 20 at...

CdTe nano-structures for photovoltaic devices

CdTe nano-structures with diameter of ∼100 nm and variable length (200–600 nm) were fabricated on glass substrates covered with conductive buffer layers such as NiCr, ZAO (ZnO:Al2O3 + Ta2O5) or TiPd alloys. The fabrication process consisted of the starting vapour deposition of metal catalyst dropped layer followed by the isothermal catalyst-prompted vapour growth of CdTe nano-structured layer of controllable sh...

Avaliação de necessidades parentais em unidades de cuidados intensivos neonatais

Utilização do diagnóstico genético pré-implantação por portadores de paramiloidose

Properties of tantalum oxynitride thin films produced by magnetron sputtering: ...

The main purpose of this work is to present and to interpret the change of structure and physical properties of tantalum oxynitride (TaNxOy) thin films, produced by dc reactive magnetron sputtering, by varying the processing parameters. A set of TaNxOy films was prepared by varying the reactive gases flow rate, using a N2/O2 gas mixture with a concentration ratio of 17:3. The different films, obtained by this p...

The role of composition, structure and morphology on the electrical, optical an...

Metallic (Me) oxynitrides (MeNxOy) are an attractive class of materials due to a unique set of versatile properties in different technological domains such as protective applications (wear, diffusion and corrosion-resistance), decorative coatings, gas barriers, microelectronics, optoelectronics, solar cells, etc. Among the group of oxynitrides, aluminium oxynitride (AlNxOy) presents some interesting characteris...