Searched for: subject:"attenuation"
(1 - 20 of 58)

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Hedayati, R. (author), Lakshmanan, Sandhya (author)
Metamaterials are periodic structures which offer physical properties not found in nature. Particularly, acoustic metamaterials can manipulate sound and elastic waves both spatially and spectrally in unpreceded ways. Acoustic metamaterials can generate arbitrary acoustic bandgaps by scattering sound waves, which is a superior property for...
journal article 2020
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Meles, G.A. (author), Zhang, L. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
Seismic images provided by reverse time migration can be contaminated by artefacts associated with the migration of multiples. Multiples can corrupt seismic images, producing both false positives, that is by focusing energy at unphysical interfaces, and false negatives, that is by destructively interfering with primaries. Multiple prediction...
journal article 2020
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Willemsen, Pim W.J.M. (author), Borsje, Bas W. (author), Vuik, V. (author), Bouma, Tjeerd J. (author), Hulscher, Suzanne J.M.H. (author)
Foreshores consisting of both bare tidal flats and vegetated salt marshes are found worldwide and they are well studied for their wave attenuating capacity. However, most studies only focus on the small scale: just some isolated locations in space and only up to several years in time. In order to stimulate the implementation of foreshores...
journal article 2020
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Armstrong, Michael (author), Ravasio, Matteo (author), Versteijlen, W.G. (author), Verschuur, D.J. (author), Metrikine, A. (author), van Dalen, K.N. (author)
Determination of soil material damping is known to be difficult and uncertain, especially in the offshore environment. Using an advanced inversion methodology based on multichannel spectral analysis, Scholte and Love wave measurements are used to characterize subsea soil from a North Sea site. After normalization, a determinant-based objective...
journal article 2020
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Phan Khanh, L. (author)
This study explores the influence of the wave characteristics on the attenuation process of waves through coastal mangroves, which are threatened by the coastal mangrove squeeze phenomenon. Coastal mangrove squeeze is the phenomenon where coastal regions, even when sediment availability is sufficient, are eroding due to a lack of accommodation...
doctoral thesis 2019
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Thouement, H.A.A. (author), Kuder, Tomasz (author), Heimovaara, T.J. (author), van Breukelen, B.M. (author)
Back-diffusion of chlorinated ethenes (CEs) from low-permeability layers (LPLs) causes contaminant persistence long after the primary spill zones have disappeared. Naturally occurring degradation in LPLs lowers remediation time frames, but its assessment through sediment sampling is prohibitive in conventional remediation projects. Scenario...
journal article 2019
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Phan Khanh, L. (author), Stive, M.J.F. (author), Zijlema, M. (author), Truong, H.T.X. (author), Aarninkhof, S.G.J. (author)
Wave attenuation through mangrove forests has received more and more attention, especially in the context of increasing coastal erosion and sea-level-rise. Numerous studies have focused on studying the reduction of wave height in a mangrove forest. However, the understanding of this attenuation process is still in its infancy. In order to obtain...
journal article 2019
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Taş, Neslihan (author), Brandt, Bernd W. (author), Braster, Martin (author), van Breukelen, B.M. (author), Röling, Wilfred F.M. (author)
Microbial communities in groundwater ecosystems can develop the capacity to degrade complex mixtures of chemicals resulting from pollution by landfill leachate. Monitoring this natural attenuation requires insight into the metabolic potential and activity of microbial communities. We contrasted the metagenomes and metatranscriptomes from a...
journal article 2018
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Vuik, V. (author), van Vuren, S. (author), Borsje, Bas W. (author), van Wesenbeeck, B.K. (author), Jonkman, Sebastiaan N. (author)
Vegetated foreshores adjacent to engineered structures (so-called hybrid flood defenses), are considered to have high potential in reducing flood risk, even in the face of sea level rise and increasing storminess. However, foreshores such as salt marshes and mangrove forests are generally characterized by relatively strong temporal and...
journal article 2018
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Vuik, V. (author), Suh Heo, H.Y. (author), Zhu, Zhenchang (author), Borsje, Bas W. (author), Jonkman, Sebastiaan N. (author)
One of the services provided by coastal ecosystems is wave attenuation by vegetation, and subsequent reduction of wave loads on flood defense structures. Therefore, stability of vegetation under wave forcing is an important factor to consider. This paper presents a model which determines the wave load that plant stems can withstand before...
journal article 2018
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Ghafaryasl, B. (author), Vermeer, K.A. (author), Kalkman, J. (author), Dore-Callewaert, T.W.J. (author), de Boer, J.F. (author), van Vliet, L.J. (author)
The attenuation coefficient (AC) is a property related to the microstructure of tissue on a wavelength scale that can be estimated from optical coherence tomography (OCT) data. Since the OCT signal sensitivity is affected by the finite spectrometer/detector resolution called roll-off and the shape of the focused beam in the sample arm,...
conference paper 2018
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Gnanadesigan, Muthukaruppan (author), Hussain, Ali S. (author), White, Stephen (author), Scoltock, Simon (author), Baumbach, Andreas (author), van der Steen, A.F.W. (author), Regar, E.S. (author), Johnson, Thomas W. (author), van Soest, G. (author)
Lipid-core atherosclerotic plaques are associated with disease progression, procedural complications, and cardiac events. Coronary plaque lipid can be quantified in optical coherence tomography (OCT) pullbacks by measurement of lipid arcs and lipid lengths; parameters frequently used in clinical research, but labor intensive and subjective to...
journal article 2017
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Liu, Shengnan (author), Sotomi, Yohei (author), Eggermont, Jeroen (author), Nakazawa, Gaku (author), Torii, Sho (author), Ijichi, Takeshi (author), Onuma, Yoshinobu (author), Serruys, Patrick W. (author), Lelieveldt, B.P.F. (author), Dijkstra, J. (author)
An important application of intravascular optical coherence tomography (IVOCT) for atherosclerotic tissue analysis is using it to estimate attenuation and backscatter coefficients. This work aims at exploring the potential of the attenuation coefficient, a proposed backscatter term, and image intensities in distinguishing different...
journal article 2017
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Weemstra, C. (author), Draganov, D.S. (author), Ruigrok, E.N. (author), Hunziker, J.W. (author), Gomez, Martin (author), Wapenaar, C.P.A. (author)
Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, the SI responses are retrieved by simple crosscorrelation of recordings made by separate receivers: one of the receivers acts as a ‘virtual source’ whose response is retrieved at the other receivers.When SI is applied...
journal article 2017
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van Breukelen, B.M. (author), Thouement, H.A.A. (author), Stack, Philip E. (author), Vanderford, Mindy (author), Philp, Paul (author), Kuder, Tomasz (author)
Reactive transport modeling of multi-element, compound-specific isotope analysis (CSIA) data has great potential to quantify sequential microbial reductive dechlorination (SRD) and alternative pathways such as oxidation, in support of remediation of chlorinated solvents in groundwater. As a key step towards this goal, a model was developed...
journal article 2017
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Barnhoorn, A. (author), Jackson, I. (author), Fitz Gerald, J. D. (author), Kishimoto, A. (author), Itatani, K. (author)
Torsional forced-oscillation experiments on a suite of synthetic MgO polycrystals, of high-purity and average grain sizes of 1–100 µm, reveal strongly viscoelastic behavior at temperatures of 800–1300°C and periods between 1 and 1000 s. The measured shear modulus and associated strain energy dissipation both display monotonic variations with...
journal article 2016
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Mangimbulude, Jubhar C. (author), Goeltom, Mangihot T. (author), van Breukelen, B.M. (author), van Straalen, NM (author), Roling, WFM (author)
The hydrochemistry of landfill leachate and groundwater is affected by not only waste degradation processes, but also by external factors such as the geography of the landfilling site. Knowledge on the fate of landfill leachate in tropical countries will be beneficial for monitoring and regulatory purposes. We studied the Keputih landfill close...
journal article 2016
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Slob, E.C. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author)
We present a scheme for Marchenko imaging in a dissipative heterogeneous medium. The scheme requires measured reflection and transmission data at two sides of the dissipative medium. The effectual medium is the same as the dissipative medium, but with negative dissipation. We show how the measured double-sided data can be combined to obtain the...
conference paper 2016
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Novosel, J. (author), Wang, Ziyuan (author), de Jong, Henk (author), Vermeer, K.A. (author), van Vliet, L.J. (author)
Optical coherence tomography (OCT) is used to produce high-resolution three-dimensional images of the retina, which permit the investigation of retinal irregularities. In dry age-related macular degeneration (AMD), a chronic eye disease that causes central vision loss, disruptions such as drusen and changes in retinal layer thicknesses occur...
conference paper 2016
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Vuik, V. (author), Jonkman, S.N. (author)
Salt marshes are a characteristic feature of estuaries and coastal seas. They are found in the upper coastal intertidal zones between land and water, which are regularly flooded by tides and surges. They are covered with salt-tolerant vegetation types, such as herbs and grasses. Sheltering from continuous intense hydrodynamic forcing by waves...
abstract 2016
Searched for: subject:"attenuation"
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