Search results for "Clima"
showing 10 items of 6069 documents
Impact of red giant/AGB winds on active galactic nucleus jet propagation
2017
Astronomy and astrophysics 606, A40 (2017). doi:10.1051/0004-6361/201630117
On the influence of a hybrid thermal-non-thermal distribution in the internal shocks model for blazars
2017
Internal shocks occurring in blazars may accelerate both thermal and non-thermal electrons. In this paper we examine the consequences that such a hybrid (thermal/non-thermal) EED has on the spectrum of blazars. Since the thermal component of the EED may extend to very low energies. We replace the standard synchrotron process by the more general magneto-bremsstrahlung (MBS). Significant differences in the energy flux appear at low radio frequencies when considering MBS instead of the standard synchrotron emission. A drop in the spectrum appears in the all the radio band and a prominent valley between the infrared and soft X-rays bands when a hybrid EED is considered, instead of a power-law E…
Cosmological shock waves: clues to the formation history of haloes
2012
Shock waves developed during the formation and evolution of cosmic structures encode crucial information on the hierarchical formation of the Universe. We analyze an Eulerian AMR hydro + N-body simulation in a $\Lambda$CDM cosmology focused on the study of cosmological shock waves. The combination of a shock-capturing algorithm together with the use of a halo finder allows us to study the morphological structures of the shock patterns, the statistical properties of shocked cells, and the correlations between the cosmological shock waves appearing at different scales and the properties of the haloes harbouring them. The shocks in the simulation can be split into two broad classes: internal w…
Assessment of Fatigue Effects Induced by Fast Beam Transients in the IFMIF-DONES Li Target
2020
One of the crucial steps toward the commercial exploitation of fusion energy is the availability of a high-intensity neutron source able to test and qualify structural materials to be used in future fusion power reactors. The International Fusion Materials Irradiation Facility-DEMO Oriented NEutron Source (IFMIF-DONES) facility, which is currently being designed within the framework of the EUROfusion Consortium, represents the European effort to develop such a neutron source. It employs a liquid lithium target struck by an accelerated deuteron (D+) beam to produce fusion-like neutrons used to irradiate materials samples. So far, a detailed investigation of the thermomechanical behavior of t…
3D simulations of microquasar jets in clumpy stellar winds
2011
High-mass microquasars consist of a massive star and a compact object, the latter producing jets that will interact with the stellar wind. The evolution of the jets, and ultimately their radiative outcome, could depend strongly on the inhomogeneity of the wind, which calls for a detailed study. The hydrodynamics of the interaction between a jet and a clumpy wind is studied, focusing on the global wind and single clump-jet interplay. We have performed, using the code \textit{Ratpenat}, three-dimensional numerical simulations of a clumpy wind interacting with a mildly relativistic jet, and of individual clumps penetrating into a jet. For typical wind and jet velocities, filling factors of abo…
Laboratory evidence for proton energization by collisionless shock surfing
2021
Charged particles can be accelerated to high energies by collisionless shock waves in astrophysical environments, such as supernova remnants. By interacting with the magnetized ambient medium, these shocks can transfer energy to particles. Despite increasing efforts in the characterization of these shocks from satellite measurements at Earth’s bow shock as well as powerful numerical simulations, the underlying acceleration mechanism or a combination thereof is still widely debated. Here we show that astrophysically relevant super-critical quasi-perpendicular magnetized collisionless shocks can be produced and characterized in the laboratory. We observe the characteristics of super-criticali…
2008
Abstract. Airborne in-situ observations of carbon dioxide (CO2) were made during 7 intensive measurement campaigns between November 2001 and April 2003 as part of the SPURT project. Vertical profiles and latitudinal gradients in the upper troposphere/lowermost stratosphere were measured along the western shore of Europe from the subtropics to high northern latitudes during different seasons. In the boundary layer, CO2 exhibits a strong seasonal cycle with the maximum mixing ratios in winter and minimum values in summer, reflecting the strength of CO2 exchange with vegetation. Seasonal variations are strongest in high latitudes and propagate to the free troposphere and lowermost stratosphere…
Recent benthic foraminiferal assemblages and their relationship to environmental variables on the shoreface and inner shelf off Valencia (Western Med…
2014
The environmental variables that determine the distributions of benthic foraminiferal assemblages on the shoreface and inner shelf of the north of Valencia province (Western Mediterranean) are identified. The possible influence of variables such as water depth, distance from shore, hydrodynamics, substrate type, carbonate content, organic matter content and human activity is evaluated. Multivariate cluster-Q-type analysis and redundancy analysis (RDA) are used to identify the environmental variables that have the greatest influence on the assemblage distribution. The spatial distribution of the assemblages is closely associated with water depth and substrate. The diversity and abundance of …
Discovery of the proton emitting nucleus $^{159}$Re
2007
Fund. para Cienc. Tecnol., FCT, Minist. Cienc. Tecnol.;Fundacao Calouste Gulbenkian;Fundacao Luso-Americana