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Smith, Caitlin (author), Shepherd, Jami (author), Renaud, G.G.J. (author), van Wijk, Kasper (author)We present a technique called photoacoustic vector-flow (PAVF) to quantify the speed and direction of flowing optical absorbers at each pixel from acoustic-resolution PA images. By varying the receiving angle at each pixel in post-processing, we obtain multiple estimates of the phase difference between consecutive frames. These are used to...journal article 2024
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- Renaud, G.G.J. (author), Minonzio, Jean Gabriel (author) journal article 2023
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Dia, Amadou Sall (author), Renaud, G.G.J. (author), Nooghabi, Aida Hejazi (author), Grimal, Quentin (author)Decreased thickness of the bone cortex due to bone loss in the course of ageing and osteoporosis is associated with reduced bone strength. Cortical thickness measurement from ultrasound images was recently demonstrated in young adults. This requires the identification of both the outer (periosteum) and inner (endosteum) surfaces of the bone...journal article 2023
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Mozaffarzadeh, M. (author), Verweij, M.D. (author), de Jong, N. (author), Renaud, G.G.J. (author)While transcranial ultrasound imaging is a promising diagnostic modality, it is still hindered due to phase aberration and multiple scattering caused by the skull. In this paper, we compare near-field phase-screen modeling (PS) to a geometry-based phase aberration correction technique (GB) when an ultrafast imaging sequence (five plane waves...journal article 2022
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Spiekhout, Sander (author), Voorneveld, J.D. (author), Van Elburg, Benjamin (author), Renaud, G.G.J. (author), Segers, Tim (author), Lajoinie, Guillaume P.R. (author), Versluis, Michel (author), Verweij, M.D. (author), de Jong, N. (author), Bosch, Johannes G. (author)Ultrasound (US) contrast agents consist of microbubbles ranging from 1 to 10 μm in size. The acoustical response of individual microbubbles can be studied with high-frame-rate optics or an "acoustical camera"(AC). The AC measures the relative microbubble oscillation while the optical camera measures the absolute oscillation. In this article,...journal article 2022
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Renaud, G.G.J. (author), Salles, Sébastien (author)In this chapter, we first review the reasons why conventional ultrasonography fails to image the interior of bones. Next we show our recent work on imaging a cortical bone layer with ultrasound. Revealing the shape of the cortex of a bone, in particular its thickness, is of interest for evaluating bone strength. In addition we describe how...journal article 2022
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Mozaffarzadeh, M. (author), Verschuur, D.J. (author), Verweij, M.D. (author), de Jong, N. (author), Renaud, G.G.J. (author)In a recent study, we proposed a technique to correct aberration caused by the skull and reconstruct a transcranial B-mode image with a refraction-corrected synthetic aperture imaging (SAI) scheme. Given a sound speed map, the arrival times were calculated using a fast marching technique (FMT), which solves the Eikonal equation and, therefore...journal article 2022
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Mozaffarzadeh, M. (author), Verschuur, D.J. (author), Verweij, M.D. (author), Daeichin, V. (author), de Jong, N. (author), Renaud, G.G.J. (author)Transcranial ultrasound imaging (TUI) is a diagnostic modality with numerous applications, but unfortunately, it is hindered by phase aberration caused by the skull. In this article, we propose to reconstruct a transcranial B-mode image with a refraction-corrected synthetic aperture imaging (SAI) scheme. First, the compressional sound...journal article 2022
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Smith, C.G. (author), Shepherd, Jami (author), Renaud, G.G.J. (author), van Wijk, Kasper (author)By changing the ultrasonic receiving angle in post-processing, we can obtain flow vectors from a photoacoustic experiment on a blood vessel phantom by solving the photoacoustic Doppler equation using a least-squares optimisation approach.conference paper 2022
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Salles, Sebastien (author), Shepherd, Jami (author), Vos, Hendrik J. (author), Renaud, G.G.J. (author)Intraosseous blood circulation is thought to have a critical role in bone growth and remodeling, fracture healing, and bone disorders. However, it is rarely considered in clinical practice because of the absence of a suitable noninvasive in vivo measurement technique. In this work, we assessed blood perfusion in tibial cortical bone...journal article 2021
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Kuruma, Kazuhiro (author), Pingault, B.J. (author), Chia, Cleaven (author), Renaud, Dylan (author), Hoffmann, Patrick (author), Iwamoto, Satoshi (author), Ronning, Carsten (author), Lončar, Marko (author)We demonstrate optical coupling between a single tin-vacancy (SnV) center in diamond and a free-standing photonic crystal nanobeam cavity. The cavities are fabricated using quasi-isotropic etching and feature experimentally measured quality factors as high as ∼11 000. We investigate the dependence of a single SnV center's emission by...journal article 2021
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Mozaffarzadeh, M. (author), Verweij, M.D. (author), Daeichin, V. (author), de Jong, N. (author), Renaud, G.G.J. (author)Transcranial ultrasound imaging is a suitable technology for diagnosis of strokes as it is safe, portable, relatively inexpensive and available in emergency medicine services, however it currently offers poor image quality due to the phase aberration caused by the human skull. In this work, we evaluate an approach for two-dimensional...conference paper 2021
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Mozaffarzadeh, M. (author), Minonzio, C.G. (author), de Jong, N. (author), Verweij, M.D. (author), Hemm, Simone (author), Renaud, G.G.J. (author), Daeichin, V. (author)In the above article [1], we mentioned that the superposition of the different symmetric (S) modes in the frequencywavenumber (f-k) domain results in a high-intensity region where its slope corresponds to the longitudinal wave speed in the slab. However, we have recently understood that this highintensity region belongs to the propagation of...journal article 2020
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Kirkwood, N.R.M. (author), De Backer, Annick (author), Longo, Alessandro (author), Geuchies, J.J. (author), Mulder, J.T. (author), Renaud, N. (author), Bals, Sara (author), Manna, L. (author), Houtepen, A.J. (author)Zinc is routinely employed in the synthesis of InP quantum dots (QDs) to improve the photoluminescence efficiency and carrier mobility of the resulting In(Zn)P alloy nanostructures. The exact location of Zn in the final structures and the mechanism by which it enhances the optoelectronic properties of the QDs are debated. We use synchrotron X...journal article 2020
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Maheswari, S. (author), Patwardhan, Sameer (author), Schatz, George C. (author), Renaud, Nicolas (author), Grozema, F.C. (author)We present ab initio calculations (DFT and SOC-G0W0) of the optoelectronic properties of different hybrid-halide perovskites, namely X-PbI3 (X = methylamonimum, formamidinium, guanidinium, hydrazinium, and hydroxylammonium). These calculations shed new light on how the substitution of different organic cations in the material influences its...journal article 2019
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Grimaldi, G. (author), Crisp, R.W. (author), Ten Brinck, Stephanie (author), Zapata, Felipe (author), van Ouwendorp, M. (author), Renaud, N. (author), Kirkwood, N.R.M. (author), Evers, W.H. (author), Kinge, S.S. (author), Infante, Ivan (author), Siebbeles, L.D.A. (author), Houtepen, A.J. (author)Thermalization losses limit the photon-to-power conversion of solar cells at the high-energy side of the solar spectrum, as electrons quickly lose their energy relaxing to the band edge. Hot-electron transfer could reduce these losses. Here, we demonstrate fast and efficient hot-electron transfer between lead selenide and cadmium selenide...journal article 2018
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Whelchel, Adam W. (author), Reguero, Borja G. (author), van Wesenbeeck, B (author), Renaud, Fabrice G. (author)By the later part of the 21st Century, our planet will be faced with compelling climatic circumstances requiring tradeoffs to maintain viable environmental conditions and standards of living. The prognosis for people near coastlines and waterways is particularly dire without decisive actions that capitalize on shared strengths such as...journal article 2018
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Maheswari, S. (author), Savenije, T.J. (author), Renaud, N. (author), Grozema, F.C. (author)Two-dimensional (2D) halide perovskites are a class of materials in which 2D layers of perovskite are separated by large organic cations. Conventionally, the 2D perovskites incorporate organic cations as spacers, but these organic cations also offer a route to introduce specific functionality in the material. In this work, we demonstrate, by...journal article 2018
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Gelvez Rueda, M.C. (author), Hutter, E.M. (author), Cao, Duyen H. (author), Renaud, N. (author), Stoumpos, Constantinos C. (author), Hupp, Joseph T. (author), Savenije, T.J. (author), Kanatzidis, Mercouri G. (author), Grozema, F.C. (author)The optoelectronic properties of hybrid perovskites can be easily tailored by varying their components. Specifically, mixing the common short organic cation (methylammonium (MA)) with a larger one (e.g., butyl ammonium (BA)) results in 2-dimensional perovskites with varying thicknesses of inorganic layers separated by the large organic cation...journal article 2017
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Gelvez Rueda, M.C. (author), Renaud, N. (author), Grozema, F.C. (author)The fundamental opto-electronic properties of organic-inorganic hybrid perovskites are strongly affected by their structural parameters. These parameters are particularly critical in formamidinium lead iodide (FAPbI<sub>3</sub>), in which its large structural disorder leads to a non-perovskite yellow phase that hinders its photovoltaic...journal article 2017
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