Search results for "numerical [Methods]"
showing 10 items of 500 documents
Observed versus simulated mountain waves over Scandinavia – improvement of vertical winds, energy and momentum fluxes by enhanced model resolut…
2017
Abstract. Two mountain wave events, which occurred over northern Scandinavia in December 2013 are analysed by means of airborne observations and global and mesoscale numerical simulations with horizontal mesh sizes of 16, 7.2, 2.4 and 0.8 km. During both events westerly cross-mountain flow induced upward-propagating mountain waves with different wave characteristics due to differing atmospheric background conditions. While wave breaking occurred at altitudes between 25 and 30 km during the first event due to weak stratospheric winds, waves propagated to altitudes above 30 km and interfacial waves formed in the troposphere at a stratospheric intrusion layer during the second event. Global an…
Unconventional phases of attractive Fermi gases in synthetic Hall ribbons
2017
An innovative way to produce quantum Hall ribbons in a cold atomic system is to use M hyperfine states of atoms in a one-dimensional optical lattice to mimic an additional "synthetic dimension." A notable aspect here is that the SU(M) symmetric interaction between atoms manifests as "infinite ranged" along the synthetic dimension. We study the many-body physics of fermions with SU(M) symmetric attractive interactions in this system using a combination of analytical field theoretic and numerical density-matrix renormalization-group methods. We uncover the rich ground-state phase diagram of the system, including unconventional phases such as squished baryon fluids, shedding light on many-body…
Application of a 1-D numerical model to estimate the sediment transported along a river
2006
Natural rivers tend to adjust their plane shape and longitudinal profile in order to assume a configuration compatible with the changing hydraulic and man-made constraints. The causes of these bed variations are related to changes in independent river channel variables (increase in water discharge, decrease in sediment discharge, etc..) or to changes in river slope. River bed degradation and aggradation, often occurring as result of river morphological changes, modify the longitudinal bed profile of the river and the amount of sediment transported along the river until to reach the outlet. As an example, the construction of river dams produces large morphological consequences: when the stre…
HR3DHG version 1: modeling the spatiotemporal dynamics of mercury in the Augusta Bay (southern Italy)
2020
The biogeochemical dynamics of Hg, and specifically of its three species Hg0, HgII, and MeHg (elemental, inorganic, and organic, respectively), in the marine coastal area of Augusta Bay (southern Italy) have been explored by the high-resolution 3D Hg (HR3DHG) model, namely an advection–diffusion–reaction model for dissolved mercury in the seawater compartment coupled with a diffusion–reaction model for dissolved mercury in the pore water of sediments in which the desorption process for the sediment total mercury is taken into account. The spatiotemporal variability of the mercury concentration in both seawater ([HgD]) and the first layers of bottom sediments ([HgDsed] and [HgTsed]), as well…
A time evolution model for total-variation based blind deconvolution
2007
Departamento Matematica Aplicada, Universidad de Valencia, Burjassot 46100, Spain.We propose a time evolution model for total-variation based blind deconvolution consisting of two evolution equations evolv-ing the signal by means of a nonlinear scale space method and the kernel by using a diffusion equation starting from the zerosignal and a delta function respectively. A preliminary numerical test consisting of blind deconvolution of a noiseless blurredimage is presented.
Tsunami Vulnerability Evaluation for a Small Ancient Village on Eastern Sicily Coast
2022
The Ionian sea is prone to tsunamis due to its proximity to the Calabrian subduction zone, which is one of the major tsunamigenic areas of the Mediterranean. The tsunami disaster risk is, nowadays, significantly higher due to the increased exposure of buildings as a result of the economic and touristic growth of the Mediterranean coastal areas. This study focuses on Marzamemi, a small village in the western coast of Sicily, since its morphology and human presence amplify the need to assess its buildings’ vulnerability. The main objective of this research is to quantify the building vulnerability to tsunami hazards using a physical and realistic tsunami scenario. For this purpose, the relati…
Use of fiber-section beam elements for modelling the monotonic flexural response of RC jacketed columns
2021
Abstract The use of reinforced concrete (RC) jacketing is a common technique for retrofitting existing RC columns with poor structural performances. Literature studies highlighted that the relative slip occurring at the interface between the new and the old concrete can affect substantially the flexibility and the strength of the retrofitted member. For this reason, several interface treatments are usually applied, aiming to induce a monolithic behaviour to the column. However, despite the commonness of RC jacketing, a limited number of studies investigated numerical modelling strategies for including these phenomena, especially with reference to the development of numerical models for desi…
Study of the performances of a fluidynamic actuator
2018
Aim of this paper is presented a new methodology to study how different geometric parameters affect the performance of a hydraulic actuator. Preliminarily, the real working conditions of a hydraulic machine have been simulated by means of a CFD module. After, to test the reliability of the simulations, the obtained numerical results have been compared with the experimental data of a real prototype. This comparison demonstrates a good level of agreement between numerical and experimental results. Different simulations have been setup by modifying the actuator geometry and evaluating the efficiency of every analysed configuration. The results of this study give useful guidelines for the choic…
Numerical-Analytical Model for Nanotube-Reinforced Nanocomposites
2013
A novel numerical model able to predict the elastic properties of carbon nanotube/polymer composites containing a random distribution of CNTs has been developed. The new technique, which takes into account of the curvature that the nanotubes show when immersed in the polymer, is based on a numerical-analytical approach that has significant advances over micromechanical modeling and can be applied to several kinds of nanostructured composites. The nature of carbon nanotube/polymer bonding has arisen as key factor in the efficacy of the carbon nanotubes to actually provide any enhanced stiffness or strength to the composite. Here the effects of carbon nanotube interface interaction with the m…
New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica
2008
A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of alpha-quartz are well-reproduced, showing th…