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Pulsed Electromagnetic Excitation of a Narrow Slot Between Two Dielectric Halfspaces

Stumpf, Martin (author), Antonini, Giulio (author), Lager, I.E. (author)

The transient electromagnetic (EM) excitation of a narrow slot in a perfectly electrically conducting (PEC) screen that separates two homogeneous dielectric halfspaces, a simplified model of a typical feeding structure of leaky lens antennas, is analyzed numerically in the time domain (TD). The problem is formulated using the TD reciprocity...

journal article 2024

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OpenFOAM design sensitivity analysis on a homogeneous low-crested structure with concrete elements seaward of a vertical seawall to reduce overtopping

Jonker, R. G. (author), AlYousif, A.Y. (author), Hofland, Bas (author), Antonini, A. (author), Zoon, Arthur (author), Smith, Gregory (author)

This study treats a detached homogenous low-crested structure (HLCS) made of Cubipod concrete elements placed seaward of a vertical wall (forming a basin in between) to reduce overtopping. Assessing the complex hydrodynamics and effects of changing the geometry of such a system in relation to overtopping reduction is challenging. The...

journal article 2024

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On the spectral wave climate of the French Atlantic Ocean

Sartini, Ludovica (author), Antonini, A. (author)

The accurate description of wave climate at different spatio-temporal scales requires the application of advanced statistical models together with a good knowledge of geophysical processes. Furthermore, accurate modelling of multimodal sea states is of primary importance for most of offshore and coastal activities, such as wave energy device...

journal article 2024

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Wolf Rock Lighthouse Long-Term Monitoring

Brownjohn, James (author), Raby, Alison (author), Bassitt, James (author), Antonini, A. (author), Zhu, Zuo (author), Dobson, Peter (author)

Wolf Rock Lighthouse is a Victorian era masonry structure located in an extreme environment facing the fiercest Atlantic storms off the southwest coast of England whose dynamic behaviour has been studied since 2016. Initially, a modal test was used to determine modal parameters; then, in 2017, a monitoring system was installed that has...

journal article 2024

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Initial tests on reversed open filters on sand-covered rock mounds

van de Ven, Daan (author), Hofland, Bas (author), van Kester, Dennis (author), Smith, Greg (author), Antonini, A. (author)

When constructing land reclamations, often sand is placed on top of the coarse rock of the bund surrounding the reclamation. The use of a geometrically open filter between the interface of sand and rock could be cost effective. It is expected that even a geometrically open filter with sand on top of gravel might be stable due to the arching...

conference paper 2023

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Embedded rocking measurement of single layer armour units: Development and first results

Houtzager, Daan (author), Hofland, Bas (author), Caldera, Ganga (author), van der Lem, Cock (author), van Gent, M.R.A. (author), Bakker, Pieter (author), Antonini, A. (author)

Randomly placed breakwater armour units under wave loading can sometimes start rocking, which can lead to breakage of armour units. This failure mechanism can especially become important for single layer randomly placed armour units for which full displacement of units will only happen at higher stability numbers compared to older types of units...

conference paper 2023

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Rocking of single-layer armour units measured by embedded sensors

Hofland, Bas (author), Houtzager, Daan (author), Caldera, Ganga (author), Antonini, A. (author), van Gent, M.R.A. (author), Bakker, Pieter (author), van der Lem, Cock (author)

Single layer randomly placed armour units are used in many rubble mound breakwaters around the world. For these armour layers first extraction of units starts at high loads and can then progress quickly. Before the first extraction of a unit, typically no quantitative description of damage can be given. But additional to extraction, breakage of...

journal article 2023

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Implications of second-order wave generation for physical modelling of force and run-up on a vertical wall using wave groups

Mortimer, William (author), Calvert, R. (author), Antonini, A. (author), Greaves, Deborah (author), Raby, Alison (author), van den Bremer, T.S. (author)

Experiments are contaminated by second-order error waves at sub- and super-harmonic frequencies when first-order wave generation is used. Herein, we investigate by experiment the implications of second-order wave generation theory for dynamic wave force and run-up on a vertical wall in shallow to intermediate water depth (k₀d=0.5−1...

journal article 2023

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Perspectives on Compound Flooding in Chinese Estuary Regions

Xu, H. (author), Ragno, E. (author), Tan, Jinkai (author), Antonini, A. (author), Bricker, J.D. (author), Jonkman, Sebastiaan N. (author), Liu, Qing (author), Wang, Jun (author)

Extreme surges and rainfall represent major driving factors for compound flooding in estuary regions along the Chinese coast. The combined effect of extreme surges and rainfall (that is, compound floods) might lead to greater impacts than if the drivers occurred in isolation. Hence, understanding the frequency and severity of compound...

journal article 2023

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Investigating extreme sea level components and their interactions in the Adriatic and Tyrrhenian Seas

Ragno, E. (author), Antonini, A. (author), Pasquali, Davide (author)

Coastal hazards represent an existential threat to Italian coastal regions since they host important economic centers related to manufacturing and tourism. Knowledge of potential extreme sea levels (ESL), their component, and their interactions are essential to better evaluate potentially hazardous future extreme events in a changing climate...

journal article 2023

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Time-Domain Analysis of Thin-Wire Structures Based on the Cagniard-DeHoop Method of Moments

Stumpf, Martin (author), Lager, I.E. (author), Antonini, Giulio (author)

Thin-wire structures in the presence or absence of a ground plane are analyzed numerically in the time domain (TD) with the aid of the Cagniard-DeHoop method of moments (CdH-MoM). It is demonstrated that the TD solution of such problems can be cast into the form of discrete time-convolution equations. Under the assumption of piecewise linear...

journal article 2022

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Correct generation of the bound set-down for surface gravity wave groups in laboratory experiments of intermediate to shallow depth

Mortimer, William (author), Raby, Alison (author), Antonini, A. (author), Greaves, Deborah (author), van den Bremer, T.S. (author)

Using linear (first-order) wave generation theory in laboratory experiments, leads to significant contamination of the wave field by free non-linear (second-order) error waves, increasingly so at shallower depths. Second-order wave generation theory has previously been established, and so has correct generation of the bound set-down, made up...

journal article 2022

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Computation of Time Domain Scattering Parameters Through the Numerical Inversion of the Laplace Transform

Loreto, Fabrizio (author), Pettanice, Giuseppe (author), Romano, Daniele (author), Stumpf, Martin (author), Lager, I.E. (author), Antonini, Giulio (author)

Time-domain (TD) methods for the solution of Maxwell's equations are particularly appealing for their ability to provide the overall characteristics of an electrical system in a single simulation run. In many situations, such TD methods require computing the system's impulse response and using it in a convolution-based solver. In this work, we...

conference paper 2022

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Evaluation of Convolution Integrals at Late-times Revisited

Lager, I.E. (author), Stumpf, Martin (author), Vandenbosch, Guy A.E. (author), Antonini, Giulio (author)

The late-time evaluation of electromagnetic (EM) field quantities yielded by convolution integrals that combine Green's functions available at discrete time samples and strictly causal excitations is critically revisited. A typical situation is used for tracing the causes of the divergent late-time behavior that is often experienced. A...

journal article 2022

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Developing a framework for the assessment of current and future flood risk in Venice, Italy

Schlumberger, J. (author), Ferrarin, Christian (author), Jonkman, Sebastiaan N. (author), Diaz-Loaiza, Andres (author), Antonini, A. (author), Fatorić, Sandra (author)

Flooding causes serious impacts on the old town of Venice, its residents, and its cultural heritage. Despite this existence-defining condition, limited scientific knowledge on flood risk of the old town of Venice is available to support decisions to mitigate existing and future flood impacts. Therefore, this study proposes a risk assessment...

journal article 2022

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Preserving Causality in Time Domain Integral Equation-Based Methods

Loreto, Fabrizio (author), Romano, Daniele (author), Antonini, Giulio (author), Stumpf, Martin (author), Lager, I.E. (author), Vandenbosch, Guy A.E. (author)

The critical relevance of ensuring the excitation's causality in electromagnetic (EM) simulations is exploited by the computation of strictly causal time domain interaction integrals as they occur in the partial element equivalent circuit (PEEC) method. Under the hypothesis of thin, almost zero thickness objects, the presented formulas represent...

conference paper 2022

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A Multidisciplinary Computational Framework for Topology Optimisation of Offshore Helidecks

Khosroshahi, Siamak Farajzadeh (author), Masina, M. (author), Antonini, A. (author), Ransley, Edward (author), Brownjohn, James Mark William (author), Dobson, Peter (author), D’Ayala, Dina (author)

Maintaining offshore steel structures is challenging and not environmentally friendly due to the frequent visits for inspection and repairs. Some offshore lighthouses are equipped with carbon steel helidecks fixed onto their lantern galleries in the 1970s to provide easy and safe access to maintenance staff and inspectors. Even though the...

journal article 2022

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Variations in Monthly Maximum Gust Speed at St Mary's, Isles of Scilly (UK)

Masina, M. (author), D’Ayala, Dina (author), Antonini, A. (author)

Long-term variations in maximum gust speeds have been analyzed using wind measurements recorded at St Mary's, Isles of Scilly, UK, and possible drivers of recent changes have been investigated. A rigorous homogenization procedure has been applied to the wind records to remove discontinuities mainly caused by non-climatic changes. Trends in...

journal article 2022

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Pulsed Electromagnetic Field Signal Transfer Across a Thin Magneto-Dielectric Sheet

Štumpf, Martin (author), Antonini, Giulio (author), Lager, I.E. (author), Vandenbosch, Guy A.E. (author)

Closed-form time-domain (TD) analytical expressions describing the electromagnetic (EM) signal transfer between two vertical dipoles through a thin, highly contrasting layer with combined magneto-dielectric properties are derived via the Cagniard–DeHoop (CdH) technique with the TD saltus-type conditions. The TD EM-field coupling between the...

journal article 2021

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Crownwall Failure Analysis through Finite Element Method

Dermentzoglou, Dimitrios (author), Castellino, Myrta (author), De Girolamo, Paolo (author), Partovi, Maziar (author), Schreppers, Gerd-Jan (author), Antonini, A. (author)

Several failures of recurved concrete crownwalls have been observed in recent years. This work aims to get a better insight within the processes underlying the loading phase of these structures due to non-breaking wave impulsive loading conditions and to identify the dominant failure modes. The investigation is carried out through an offline one...

journal article 2021