277 research outputs found
Pluvial flooding: high-resolution stochastic hazard mapping in urban areas by using fast-processing DEM-based algorithms
Climate change and rapid expansion of urban areas are expected to increase pluvial flood hazard and risk in the
near future, and particularly so in large developed areas and cities. Therefore, large-scale and high-resolution
pluvial flood hazard mapping is required to identify hotspots where mitigation measures may be applied to
reduce flood risk. Depressions or low points in urban areas where runoff volumes can be stored are prone to
pluvial flooding. The standard approach based on estimating synthetic design hyetographs assumes, in a given
depression, that the T-year design storm generates the T-year pluvial flood. In addition, urban areas usually
include several depressions even linked or nested that would require distinct design hyetographs instead of using
a unique synthetic design storm. In this paper, a stochastic methodology is proposed to address the limitations of
this standard approach, developing large-scale ~ 2 m-resolution pluvial flood hazard maps in urban areas with
multiple depressions. The authors present an application of the proposed approach to the city of Pamplona in
Spain (68.26 km2)
Sequential and Direct Two-Photon Double Ionization of D₂ at Flash
Sequential and direct two-photon double ionization (DI) of D2 molecule is studied experimentally and theoretically at a photon energy of 38.8 eV. Experimental and theoretical kinetic energy releases of D++D+fragments, consisting of the contributions of sequential DI via the D2+(1sσg) state and direct DI via a virtual state, agree well with each other
Heart rate, net transport cost and stride characteristics of horses exercising at walk and trot on positive and negative gradients
Airflow and nanoparticle deposition in rat nose under various breathing and sniffing conditions—A computational evaluation of the unsteady and turbulent effect
Handedness-dependent quasiparticle interference in the two enantiomers of the topological chiral semimetal PdGa
It has recently been proposed that combining chirality with topological band theory results in a totally new class of fermions. Understanding how these unconventional quasiparticles propagate and interact remains largely unexplored so far. Here, we use scanning tunneling microscopy to visualize the electronic properties of the prototypical chiral topological semimetal PdGa. We reveal chiral quantum interference patterns of opposite spiraling directions for the two PdGa enantiomers, a direct manifestation of the change of sign of their Chern number. Additionally, we demonstrate that PdGa remains topologically non-trivial over a large energy range, experimentally detecting Fermi arcs in an energy window of more than 1.6eV that is symmetrically centered around the Fermi level. These results are a consequence of the deep connection between chirality in real and reciprocal space in this class of materials, and, thereby, establish PdGa as an ideal topological chiral semimetal. Direct visualization of chiral effects in topological chiral semimetals remains elusive. Here, Sessi et al. demonstrate that quasiparticle scattering at impurities in the two enantiomers of PdGa gives rise to handedness dependent quantum interference patterns
Investigating Two-Photon Double Ionization of D₂ by XUV-Pump / XUV-Probe Experiments at FLASH
Using a novel split-mirror set-up attached to a Reaction Microscope at the Free electron LASer in Hamburg (FLASH) we demonstrate an XUV-pump - XUV-probe (ħω - 38 eV) experiment by tracing the ultra-fast nuclear wave-packet motion in the D2+(1sσg-state) with \u3c 10fs time resolution. Comparison with time-dependent calculations yields excellent agreement with the measured vibrational period of 22±4 fs in D2+, points to the importance of the inter-nuclear distance dependent ionization probability and paves the way to control sequential and non-sequential two-photon double ionization contributions
Measurement of the angle between jet axes in PbPb collisions at TeV
International audienceThis letter presents the first measurement of the angle between different jet axes (denoted as ) in PbPb collisions. The measurement is carried out in the 010% most-central events at TeV. Jets are assembled by clustering charged particles at midrapidity using the anti- algorithm with resolution parameters and and transverse momenta in the intervals GeV/ and GeV/, respectively. Measurements at these low transverse momenta enhance the sensitivity to quarkgluon plasma (QGP) effects. A comparison to models implementing various mechanisms of jet energy loss in the QGP shows that the observed narrowing of the PbPb distribution relative to pp can be explained if quark-initiated jets are more likely to emerge from the medium than gluon-initiated jets. These new measurements discard intra-jet broadening as described in a model calculation with the BDMPS formalism as the main mechanism of energy loss in the QGP. The data are sensitive to the angular scale at which the QGP can resolve two independent splittings, favoring mechanisms that incorporate incoherent energy loss
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