
Vicente Pérez-Muñuzuri- PhD Physics
- Professor at University of Santiago de Compostela
Vicente Pérez-Muñuzuri
- PhD Physics
- Professor at University of Santiago de Compostela
About
220
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Introduction
Current institution
Publications
Publications (220)
Background
Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo, often effectively treated with standard canalith repositioning maneuvers (CRMs). However, approximately 12.5% of cases remain refractory, leading to persistent symptoms and increased healthcare burden. Variations in the anatomical orientation of the semicirc...
Cardiovascular diseases are a leading cause of death globally. Among them, some are linked to stenosis, which is an abnormal narrowing of blood vessels, as well as other factors. Smart drug delivery systems based on micro- and nanoparticles are a promising method to offer non/minimal-invasive therapeutic mechanisms. Here we investigate the propensi...
Background
High-field magnetic resonance imaging (MRI) is a powerful diagnostic tool but can induce unintended physiological effects, such as nystagmus and dizziness, potentially compromising the comfort and safety of individuals undergoing imaging. These effects likely result from the Lorentz force, which arises from the interaction between the MR...
Marine plastic litter is an emerging global problem with serious environmental and economic consequences. Once deposited in the ocean, it is transported by currents for long periods of time, making it a transboundary problem. The variety of plastic items makes the study of their transport in the ocean system a challenge. Identifying the sources and...
Plastic fragmentation alters the size distribution of plastic waste in aquatic habitats, which is accelerated by mechanical stress and weathering degradation processes. Microplastic pieces constitute the vast bulk of plastic pollution in terms of quantity. Their size distribution has been shown to follow a power-law for larger fragments. This work...
Objectives:
Canalith repositioning procedures to treat benign paroxysmal positional vertigo are often applied following standardized criteria, without considering the possible anatomical singularities of the membranous labyrinth for each individual. As a result, certain patients may become refractory to the treatment due to significant deviations...
Recent results demonstrated that the use of AI to perform complicated segmentation of medical images becomes very useful when the coronary arteries are considered. Nevertheless, the different segments of the coronary arteries (distal, middle and proximal) exhibit singularities, mostly linked to section changes and image visibility, that point in th...
The Head Impulse Test, the most widely accept test to assess the vestibular function, comprises rotations of the head based on idealized orientations of the semicircular canals, instead of their individual arrangement specific for each patient. In this study, we show how computational modelling can help personalize the diagnosis of vestibular disea...
Cobia (Rachycentron canadum) is a coastal pelagic migratory fish species of tropical and subtropical waters, where it is an important game fish and it has been commercially expanded in offshore aquaculture systems. Understanding population connectivity is of utmost importance to the sustainable use and conservation of aquatic resources, and informa...
Coronary artery segmentation from CT scans is a helpful tool for coronary artery diseases diagnosis, which is frequently characterised by a vessel narrowing (stenosis). This is a highly demanded and high time-consuming process, thus automated procedures are becoming increasingly necessary. In this work, we propose an extremely light computationally...
The onset of viscous fingering in the presence of a viscosity profile is investigated theoretically for two immiscible fluids undergoing a time-dependent injection. Here, we show that the presence of a positive viscosity gradient at the interface between both fluids stabilizes the interface facilitating the spread of the perturbation. This effect i...
A priori, cosmic‐ray measurements offer a unique capability to determine the vertical profile of atmospheric temperatures directly from ground. However, despite the increased understanding of the impact of the atmosphere on cosmic‐ray rates, attempts to explore the technological potential of the latter for atmospheric physics remain very limited. I...
Marine debris is a growing problem in recent years due to population growth around the world. The incorrect management of plastic waste causes these bodies reach the seas and oceans, becoming a worldwide problem. Once they reach the seas and oceans, they begin a long period of degradation, moving from a macro state (plastics whose diameter is great...
Concern about heavy precipitation events has increasingly grown in the last years in southern Europe, especially in the Mediterranean region. These occasional episodes can result in more than 200 mm of rainfall in less than 24 h, producing flash floods with very high social and economic losses. To better understand these phenomena, a correct identi...
A priori, cosmic-ray measurements offer a unique capability to determine the vertical profile of atmospheric temperatures directly from ground. However, despite the increased understanding of the impact of the atmosphere on cosmic-ray rates, attempts to explore the technological potential of the latter for atmospheric physics remain very limited. I...
Wave energy resource assessment is crucial for the development of the marine renewable industry. High-frequency radars (HF radars) have been demonstrated to be a useful wave measuring tool. Therefore, in this work, we evaluated the accuracy of two CODAR Seasonde HF radars for describing the wave energy resource of two offshore areas in the west Gal...
Concern about heavy precipitation events has increasingly grown in the last years in Southern Europe, especially in the Mediterranean region. These occasional episodes can result in more than 200 mm of rainfall in less than 24 h, producing flash floods with very high social and economic losses. To the better understanding of this phenomena, a corre...
Abstract A high time resolution 2 m2 tracking detector, based on timing Resistive Plate Chamber (tRPC) cells, has been installed at the Faculty of Physics of the University of Santiago de Compostela (Spain) in order to improve our understanding of the cosmic rays arriving at the Earth's surface. Following a short commissioning of the detector, a st...
High-frequency (HF) radars are efficient tools for measuring vast areas and gathering ocean parameters in real-time. However, the accuracy of their wave estimates is under analysis. This paper presents a new methodology for analyzing and validating the wave data estimated by two CODAR SeaSonde radars located on the Galician coast (NW Spain). Approx...
A high resolution 2 m$^2$ tracking detector, based on timing Resistive Plate Chamber (tRPC) cells, has been installed at the Faculty of Physics of the University of Santiago de Compostela (Spain) in order to improve our understanding of the cosmic rays arriving at the Earth's surface. Following a short commisioning of the detector, a study of the a...
We present measurements of the full velocity gradient and dissipation rate tensor based on dense fields of fluid particle trajectories in homogeneous turbulence at Rel~270 and ~350 in a von Kármán flow between two counter-rotating propellers. Applying the Shake-The-Box (STB) particle tracking algorithm, we are able to instantaneously track up to ~1...
Seemingly minor details of mathematical and computational models of evolution are known to change the effect of population structure on the outcome of evolutionary processes. For example, birth-death dynamics often result in amplification of selection, while death-birth processes have been associated with suppression. In many biological populations...
A long-term multi-parameter skill assessment of a 5-MHz Coastal Ocean Dynamics Applications Radar (CODAR) SeaSonde High-Frequency radar (HFR) network deployed along the Galician Coast (NW Iberian Peninsula) was attempted for 2014–2016. To this aim, wave estimations from two HFR sites, obtained directly by the CODAR radar proprietary software, were...
Different evolutionary models are known to make disparate predictions for the success of an invading mutant in some situations. For example, some evolutionary mechanics lead to amplification of selection in structured populations, while others suppress it. Here, we use computer simulations to study evolutionary populations moved by flows, and show...
With the aim of gathering oceanographic parameters, among other technologies, a High Frequency (HF) Radar network is deployed on the Galician coast (Lorente et at, 2018.). This consists of four 5 MHz broad-beam radars, which are generating current and wave parameters. This work attempts to design a technique for validating and improving wave parame...
Two Lagrangian tracer tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle, which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle to follow flow path lines exactly. In a different approach, t...
In evolutionary dynamics, the notion of a ‘well-mixed’ population is usually associated with all-to-all interactions at all times. This assumption simplifies the mathematics of evolutionary processes, and makes analytical solutions possible. At the same time the term ‘well-mixed’ suggests that this situation can be achieved by physically stirring t...
The third edition of the international workshop “Nonlinear Processes in Oceanic and Atmospheric Flows” was held at the Institute of Mathematical Sciences (ICMAT) in Madrid from 6 to 8 July 2016. The event gathered oceanographers, atmospheric scientists, physicists, and applied mathematicians sharing a common interest in the nonlinear dynamics of ge...
Two Lagrangian tracers tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle follows flow path lines exactly. In a different approach, the...
Understanding hemodynamics in blood circulation is crucial in order to unveil the mechanisms underlying the formation of stenosis and atherosclerosis. In fact, there are experimental evidences pointing out to the existence of some given vessel configurations that are more likely to develop the above mentioned pathologies. Along this manuscript, we...
The Galician coast (NW Spain) is a region that is strongly influenced by the presence of low pressure systems in the mid-Atlantic Ocean and the periodic passage of storms that give rise to severe sea states. Since its wave climate is one of the most energetic in Europe, the objectives of this paper were twofold. The first objective was to character...
In evolutionary dynamics, well-mixed populations are almost always associated with all-to-all interactions; mathematical models are based on complete graphs. In most cases, these models do not predict fixation probabilities in groups of individuals mixed by flows. We propose an analytical description in the fast-flow limit. This approach is valid f...
Large-scale tropospheric mixing and Lagrangian transport properties have been analyzed for the long-term period 1979–2014 in terms of the finite-time Lyapunov exponents (FTLEs). Wind field reanalyses from the European Centre for Medium-Range Weather Forecasts were used to calculate the Lagrangian trajectories of large ensembles of particles. Larger...
Seasonal forecasts have improved during the last decades, mostly due to an increase in understanding of the coupled ocean–atmosphere dynamics, and the development of models able to predict the atmosphere variability. Correlations between different teleconnection patterns and severe weather in different parts of the world are constantly evolving and...
Models of species coexistence often involve spatial heterogeneity, generated by an interplay of environmental flow and biological dynamics. To characterise this scenario, we consider a finite community of two different species, advected by a chaotic flow. Intrinsic stochasticity eventually leads to the extinction of one species. Contrary to intuiti...
Large-scale tropospheric mixing and Lagrangian transport properties have been analyzed for a long-term period 1979–2014 in terms of the finite-time Lyapunov exponents (FTLE). Wind fields reanalysis from the European Centre for Medium-Range Weather Forecasts were used to calculate Lagrangian trajectories of large ensembles of particles. The FTLE cli...
Cosmic rays originating from extraterrestrial sources are permanently arriving at Earth atmosphere, where they produce up to billions of secondary particles. The analysis of the secondary particles reaching to the surface of the Earth may provide a very valuable information about the Sun activity, changes in the geomagnetic field and the atmosphere...
We present measurements of dense fields of fluid particle trajectories in homogeneous turbulence at Re lambda -270 and -350 in a von Karman flow between two counter-rotating propellers. Applying the Shake-The-Box particle tracking algorithm, we are able to instantaneously track up to 100.000 particles in a volume of 50x50x15mm3. The mean inter-part...
Seasonal forecasts have improved during the last decades, mostly due to an increase of understanding of the coupled ocean-atmosphere dynamics, and the development of models able to predict the atmosphere variability. Correlations between different teleconnection patterns and severe weather in different parts of the world have also evolved during th...
The problem of synchronization of finite-size chemical oscillators described by active inertial particles is addressed for situations in which they are immersed in a reacting nonstationary chaotic flow. Active substances in the fluid will be modeled by Lagrangian particles closely following the fluid streamlines. Their interaction with the active i...
The motion of contracting and expanding bubbles in an incompressible chaotic flow is analyzed in terms of the finite-time Lyapunov exponents. The viscous forces acting on the bubble surface depend not only on the relative acceleration but also on the time dependence of the bubble volume, which is modeled by the Rayleigh-Plesset equation. The effect...
The present study aims to improve the calculus of finite-time Lyapunov
exponents (FTLEs) applied to describe the transport of inertial particles in
a fluid flow. To this aim, the deformation tensor is modified to take into
account that the stretching rate between particles separated by a certain
distance is influenced by the initial velocity of the...
Research on cosmic rays is of big interest either for getting a better understanding about their origin and properties or because they offer very valuable information about the galactic, the solar and the Earth's environment. In order to improve our knowledge of all those fields, a high resolution cosmic ray tracking detector, TRAGALDABAS, is being...
The present study aims to improve the calculus of Finite-Time Lyapunov
Exponents (iFTLEs) applied to describe the transport of inertial
particles in a fluid flow. To this aim, the deformation tensor used to
obtain the iFTLE is modified to take into account that the stretching
rate between particles separated by a certain distance is influenced
by t...
We show that filamentous Atmospheric Rivers (ARs) over the Northern Atlantic Ocean are closely linked to attracting Lagrangian Coherent Structures (LCSs) in the large scale wind field. The detected LCSs represent lines of attraction in the evolving flow with a significant impact on all passive tracers. Using Finite-Time Lyapunov Exponents, we extra...
Clustering of inertial particles is analyzed in chaotic compressible flows. A simplified dynamical model for the motion of inertial particles in a compressible flow has been derived. Clustering enhancement has been observed for intermediate Stokes times and characterized in terms of the number of particles with negative finite-time Lyapunov exponen...
We show that filamentous Atmospheric Rivers (ARs) over the Northern Atlantic
Ocean are closely linked to attracting Lagrangian Coherent Structures (LCSs) in
the large scale wind field. LCSs represent lines of attraction in the evolving
flow with a significant impact on all passive tracers. Using Finite-Time
Lyapunov Exponents (FTLE), we extract LCS...
Cosmic rays of a wide range of energies are arriving permanently to the Earth coming from the Sun or beyond our solar system. Their study is of interest for many fields of research. A high granularity and high time resolution cosmic ray tracking detector, TRAGALDABAS, based on timing RPC cells, has been recently installed at the Faculty of Physics...
The effect of compressibility on the mixing of Lagrangian tracers is analyzed in chaotic stirred flows. Mixing is studied in terms of the finite-time Lyapunov exponents. Mixing and clustering of passive tracers surrounded by Lagrangian coherent structures is observed to increase with compressibility intensity. The role of the stirring rate and comp...
Spatial maps of the finite-time Lyapunov exponent (FTLE) have been used
extensively to study LCS in two-dimensional dynamical systems, in
particular with application to transport in unsteady fluid flows. We use
the time-periodic double-gyre model to compare spatial fields of FTLE
and the path-integrated Eulerian Okubo-Weiss parameter (OW). Both fie...
In the absence of advection, reaction-diffusion systems are able to organize into spatiotemporal patterns, in particular spiral and target waves. Whenever advection is present that can be parametrized in terms of effective or turbulent diffusion D_{*}, these patterns should be attainable on a much greater, boosted length scale. However, so far, exp...
In absence of advection, reaction-diffusion systems are able to organize into
spatiotemporal patterns, in particular spiral and target waves. Whenever
advection is present and can be parameterised in terms of effective or
turbulent diffusion $D_{*}$, these patterns should be attainable on much
greater, boosted lengthscale. However, so far, experime...
Global models are generally capable of reproducing the observed trends in the globally averaged sea surface temperature (SST). However, the global models do not perform as well on regional scales. Here, we present an ocean forecast system based on the Regional Ocean Modelling System (ROMS), the boundary conditions come from the MERCATOR ocean syste...
We study the submesoscale surface transport in the Ria de Vigo, NW
Spain, an estuary with tidal and wind-driven circulation, analyzing the
output of the coastal model MOHID with state-of-the-art Lagrangian
methods, and comparing the results to drifter experiments. We extract
Lagrangian Coherent Structures (LCS) as ridges in fields of the
Finite-Tim...
We study the relation between advection by mesoscale eddies and jets and
the remarkable eastward propagation of the Madagascar plankton bloom.
Analyzing geostrophic velocity fields from altimetry with
state-of-the-art Lagrangian techniques, we find fast coherent zonal jets
in the recently discovered South Indian Ocean Countercurrent (SICC) at
the e...
Based on ten years (1998-2007) of satellite ocean color data we
analyze the spatiotemporal patterns in the seasonal Madagascar plankton
bloom with respect to the advection of the recently discovered Southern
Indian Ocean Countercurrent (SICC). In maps of Finite-time Lyapunov
Exponents (FTLE) and Finite-Time Zonal Drift (FTZD) computed from
altimetr...
ARCOPOL is an ERDF (European Regional Development Fund) funded project framed in the Atlantic Area Transnational Programme that aims at improving the preparedness, response and mitigation capabilities of local and regional responders to accidental coastal pollution; specifically against oil, HNS (Hazardous and Noxious Substances) and inert spills....
The nontrivial dependence of the asymptotic diffusion on noise intensity has been studied for a Hamiltonian flow mimicking the Gulf Jet Stream. Three different diffusion regimes have been observed depending on the noise intensity. For intermediate noise the asymptotic diffusion decreases with noise intensity at a rate which is linearly dependent to...
Traveling wave fronts are considered for a one-dimensional array of Chua's circuits. This solution is obtained analytically and analyzed for the "primary real bifurcation". For diffusion coefficients less than some nonzero critical value it has been observed numerically that the traveling fronts fail to propagate. This nonlinear phenomena is simila...
In this work the dynamics of coupled nonlinear oscillators, which are ubiquitous in biology, is experimentally studied by using electrical relaxation oscillators. The results of this analog computation obtained with two and three coupled oscillators are in agreement with the results known from numerical approaches. Phase death, which is a mutual an...
Spatiotemporal pattern formation occurring in discretely-coupled nonlinear dynamical systems has been studied numerically. Reaction-diffusion systems can be viewed as an assembly of a large number of identical local subsystems which are coupled to each other by diffusion. Here, the local subsystems are defined by a system of nonlinear ordinary diff...
We report the experimental observation of Richardson dispersion and a double cascade in a thin horizontal fluid flow induced by Faraday waves. The energy spectra and the mean spectral energy flux obtained from particle image velocimetry data suggest an inverse energy cascade with Kolmogorov type scaling E(k) ∝ k(γ), γ ≈ -5/3 and an E(k) ∝ k(γ), γ ≈...
ARCOPOL is an European Regional Development Fund (ERDF) funded project framed in the Atlantic Area Transnational Programme that aims to improve the preparedness, response and mitigation capabilities of local and regional responders to accidental coastal pollution; specifically against oil, HNS (Hazardous and Noxious Substances) and inert spills.
Pattern formation in reaction-diffusion systems is an important self-organizing mechanism in nature. Dynamics of systems with normal diffusion do not always reflect the processes that take place in real systems when diffusion is enhanced by a fluid flow. In such reaction-diffusion-advection systems diffusion might be anomalous for certain time and...
Horizontal mixing has been found to play a crucial role in the development of spatial plankton structures in the ocean. We study the influence of time and length scales of two different horizontal two-dimensional (2-D) flows on the growth of a single phytoplankton patch. To that end, we use a coupled model consisting of a standard three component e...
We study the two-dimensional time dependent surface currents at the western coast of Galicia, Spain, including estuarines (Rias Baixas) and off-shore regions (Costa da Morte). Turbulence in ocean currents plays an important role for the mixing of water volumes with different scalar properties. The spatial structures of the current indicate, where t...
We present experiments on the propagation of a wave front in a fluid forced by Faraday waves. The vertical periodical modulation
of the acceleration induces flows in the system that modifies the Belousov-Zhabotinsky (BZ) chemical reaction dynamics. Phase
waves spreading through standing waves with different symmetries results in superdiffusion. The...
Wind measurements from SeaWinds scatterometer on the NASA QuikSCAT satellite and wind forecasts from two different operational numerical models provided by MeteoGalicia were compared for a 4-year period (2002–2005) in Galician coast environment. Available wind data buoy measurements were also used to complement the analysis. A statistical analysis...
Classical Faraday experiments were conducted on the oscillatory chemical Belousov-Zhabotinsky (BZ) reaction. The vertical periodic modulation of the acceleration induces flows in the system that change the BZ dynamics, and thus the patterns exhibited. The resulting reaction-diffusion-advection system exhibits four different types of pattern for inc...
On November 13, 2002, the Prestige tanker, loaded with about 77,000 tonnes of
fuel-oil, had an accident in front of Fisterra (Galicia, NW Spain), sinking six days later with 60,000
tonnes of fuel in the tanks and provoking the longest and most extensive, in
affected area, black tide on the Spanish coast. According to official data, the
Prestige rel...
The effect of a time-periodic chaotic shear flow on an excitable chemical medium is studied numerically. Stirring effects on pattern formation strongly depend on the shear amplitude and the ratio of the advective and chemical time scales (Damköhler number, Da). We have observed that the wave period increases with decreasing Da below some critical v...
We describe experiments on Bénard–Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Bénard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and introducto...
1
Física Teórica, Facultad de Ciencias, Universidad de Salamanca, E-37008 Salamanca, Spain
2
Departamento de Física Aplicada, Universidad de Cantabria, E-39005 Santander, Spain
3
Group of Nonlinear Physics, Faculty of Physics, University of Santiago de Compostela, E-15706 Santiago de Compostela, Spain
The west coast of Iberian Peninsula, surrounded by the Atlantic Ocean, is characterised by complex topography and specific synoptical situations that imply mesoscale circulations development. The main purpose of this work is to analyse how mesoscale circulations induced by topography and/or land use control pollutants dispersion in a coastal region...
The effect of a time-dependent flow in an oscillatory chemical system supporting front propagation is studied. Resonant target patterns depend on the strength and frequency of the time-dependent flow. The flow time scale needed to entrain the system to the resonant target period of oscillation depends on the closeness to the natural oscillation fre...
An integrated system named METEOMOHID, developed by MeteoGalicia in the first stage of the Prestige accident in November 2002 was used successfully in an operational form to support decision making and assist in recovering tasks. Afterwards, METEOMOHID has been enhanced with the aim of developing an operational oceanography system to be used in the...
A wave forecasting system based on the third generation model WAVEWATCH III was developed by MeteoGalicia (Regional Meteorological Office of Galicia). During 2005 two implementations of the wave forecasting system were operational, running daily to perform a wave forecast at different scales for the next 96 h. In the initial implementation, wave ge...
We investigate the self-organization of two-dimensional activator-inhibitor discrete bistable systems in the neighborhood of a nonequilibrium Ising-Bloch bifurcation. The system exhibits an anomalous transition--induced by discretization--whose signature is the coexistence of Ising and Bloch walls for selected values of the spatial coupling. After...
The role of spatially correlated stochastic perturbations on a Morris-Lecar neural network subject to an aperiodic subthreshold signal is analyzed in detail. Our results suggest that optimum signal-to-noise ratios can be obtained for two critical noise intensities due to the interplay of the subthreshold Poisson process and the correlated Gaussian...
The effect of space-discretization in the onset of traveling fronts in symmetrically bistable media is studied. For the FitzHugh–Nagumo model stable standing and propagating front solutions coexist. In the continuum limit this region of coexistence shrinks to a (double-zero eigenvalue) point. The unfolding of this point severely restricts the possi...
Numerical evidence is presented of a coherence-resonant behavior, induced on an atmospheric global circulation model by a white (in time and space) additive Gaussian noise with amplitude A < 1 . Intermediate A values enhance the spatiotemporal regularity of vortical patterns that contribute to the intra-annual variability of the atmospheric compone...