Exploració per tema "Heli"
Ara es mostren els items 1-19 de 19
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A rockoon closed helium buoyancy system; a first assessment
(British Interplanetary Society, 2023-03-30)
Article
Accés restringit per política de l'editorialIt is believed that the use of rockoons will revolutionize the space industry by giving priority service to microsatellite developers that now are secondary payloads for large rocket companies. However, stratospheric ... -
Development of flow regime maps for lead lithium eutectic–helium flows
(2020-09-01)
Article
Accés obertnstitute for Plasma Research (IPR), Gandhinagar (India) is currently involved in the design and development of its Lead-Lithium Ceramic Breeder (LLCB) module for testing in the International Thermo-nuclear Experimental ... -
Estudi i disseny del xassís d’un dron sustentat amb gas heli
(Universitat Politècnica de Catalunya, 2023-07-05)
Treball Final de Grau
Accés restringit per acord de confidencialitatL'objectiu d'aquest projecte és crear un dron sostingut amb heli que potenciï i millori l'autonomia i l'adaptabilitat dels drons comercials. El dron pot volar durant períodes més llargs utilitzant heli com a agent d'elevació, ... -
Excitonic insulator to superconductor phase transition in ultra-compressed helium
(2023-07-25)
Article
Accés obertHelium, the second most abundant element in the universe, exhibits an extremely large electronic band gap of about 20 eV at ambient pressures. While the metallization pressure of helium has been accurately determined, thus ... -
First-principles modeling of three-body interactions in highly compressed solid helium
(2015-12-31)
Article
Accés obertWe present a set of three-body interaction models based on the Slater-Kirkwood (SK) potential that are suitable for the study of the energy, structural, and elastic properties of solid He4 at high pressure. Our effective ... -
Henry's constant of helium in liquid alkali metals
(2024-02)
Article
Accés obertThe determination of the solubility of helium in liquid lithium and in lead-lithium eutectic systems is of crucial importance for the assessment of the reliability, safety and efficiency of future nuclear reactor plants ... -
High altitude balloon mission design and implementation for a mini-launcher
(Universitat Politècnica de Catalunya, 2011-04-08)
Treball Final de Grau
Accés obertDurante muchos años, las sondas estratosféricas han sido usadas para experimentos atmosféricos. Los nuevos globos de LATEX de bajo coste permiten poner hasta 4 kilogramos de carga de pago en el espacio cercano. Típicamente, ... -
Layering transition in superfluid helium adsorbed on a carbon nanotube mechanical resonator
(American Institute of Physics (AIP), 2019-04-23)
Article
Accés obertHelium is recognized as a model system for the study of phase transitions. Of particular interest is the superfluid phase in two dimensions. We report measurements on superfluid helium films adsorbed on the surface of a ... -
Microscopic approach to the response of 3 - 4 He mixtures
(American Physical Society (APS), 1996-10-01)
Article
Accés obertCorrelated-basis-function perturbation theory is used to evaluate the zero-temperature response S(q,¿) of 3-4He mixtures for inelastic neutron scattering, at momentum transfers q ranging from 1.1 to 1.8 A°-1. We adopt a ... -
Neutron Ionization of Helium near the Neutron-Alpha Particle Collision Resonance
(IOP, 2020-09-10)
Article
Accés obertNeutron-impact single and double ionization cross sections of the He atom are calculated near the neutron-alpha particle collision resonance. Calculations using the time-dependent close-coupling method for total and ... -
Nucleation of helium in liquid lithium at 843 K and high pressures
(Multidisciplinary Digital Publishing Institute (MDPI), 2022-04-13)
Article
Accés obertFusion energy stands out as a promising alternative for a future decarbonised energy system. In order to be sustainable, future fusion nuclear reactors will have to produce their own tritium. In the so-called breeding ... -
Nucleation of helium in pure liquid lithium
(American Institute of Physics (AIP), 2023-07-14)
Article
Accés obertTritium self-sufficiency in fusion nuclear reactors will be based on the neutron capture by lithium in the so-called breeding blankets of the reactor, a nuclear reaction that will produce helium along with tritium. The low ... -
On the stability of small vacancy clusters in solid 4He
(2011-03)
Article
Accés restringit per política de l'editorialWe study numerically properties of multiple vacancies in solid 4He at zero temperature. Up to four vacancies were introduced into the solid through incommensuration between the number of available lattice sites and the ... -
Partially Diffusive Helium-Silica Compound under High Pressure
(Institute of Physics (IOP), 2022-06-01)
Article
Accés obertHelium is the second most abundant element in the universe, and together with silica, they are important components of giant planets. Exploring the reactivity and state of helium and silica under high pressure is crucial ... -
Quantum halo states in helium tetramers
(2017-01-12)
Article
Accés obertThe universality of quantum halo states enables a comparison of systems from different fields of physics, as demonstrated in two- and three-body clusters. In the present work, we studied weakly bound helium tetramers in ... -
Quantum phase transition with a simple variational ansatz
(2014-12-11)
Article
Accés obertWe study the zero-temperature quantum phase transition between liquid and hcp solid He-4. We use the variational method with a simple yet exchange-symmetric and fully explicit wave function. It is found that the optimized ... -
Structure of halo and quasi-halo helium–helium–alkali trimers
(2017-05-01)
Article
Accés obertWe report a diffusion Monte Carlo study of A4He2 and A4He3He trimers’ structural properties, were A is one of the alkali atoms 6,7Li, 23Na, 39K, 85Rb or 133Cs. Some of them are in a pure halo state, characterized by large ... -
The limit of mechanical stability in quantum crystals: a diffusion Monte Carlo study of solid He-4
(2015-07-01)
Article
Accés obertWe present a first-principles study of the energy and elastic properties of solid helium at pressures below the range in which it is energetically stable. We find that the limit of mechanical stability in hcp He is bar, ...