Scattering reflection matrix approach to ultra-deep imaging through biological media (Conference Presentation)

2018 ◽  
Author(s):  
Laura Cobus ◽  
Amaury Badon ◽  
Dayan Li ◽  
Geoffroy Lerosey ◽  
Claude Boccara ◽  
...  
Keyword(s):  
Matrix Approach ◽  
Biological Media ◽  
Deep Imaging ◽  
Reflection Matrix

Reflection matrix approach in a multiple scattering regime: Application to the tracking of a sinking sphere in quicksand

2021 ◽  
Vol 150 (4) ◽  
pp. A195-A195
Author(s):  
Arthur Le Ber ◽  
Flavien Bureau ◽  
Xiaoping Jia ◽  
Arnaud Tourin ◽  
Mathias Fink ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Matrix Approach ◽  
Reflection Matrix

scholarly journals Reflection Matrix Approach for Quantitative Imaging of Scattering Media

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
William Lambert ◽  
Laura A. Cobus ◽  
Mathieu Couade ◽  
Mathias Fink ◽  
Alexandre Aubry
Keyword(s):  
Quantitative Imaging ◽  
Matrix Approach ◽  
Scattering Media ◽  
Reflection Matrix

scholarly journals Deep imaging in highly scattering media by combining reflection matrix measurement with Bessel-like beam based optical coherence tomography

2018 ◽  
Vol 113 (1) ◽  
pp. 011106 ◽  
Author(s):  
Qiang Yang ◽  
Yusi Miao ◽  
Tiancheng Huo ◽  
Yan Li ◽  
Emon Heidari ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Scattering Media ◽  
Deep Imaging ◽  
Reflection Matrix

Passive seismic matrix imaging of La Soufrière of Guadeloupe volcano

2021 ◽  
Author(s):  
Elsa Giraudat ◽  
Arnaud Burtin ◽  
Alexandre Aubry
Keyword(s):  
Seismic Noise ◽  
Seismic Imaging ◽  
Physical Parameters ◽  
Matrix Approach ◽  
Scattering Media ◽  
Reflection Matrix ◽  
Rough Approximation ◽  
Passive Seismic ◽  
Phase Distortions ◽  
Distortion Matrix

<p>Volcanoes are among the most challenging media for seismic imaging given their highly localized and abrupt variations in physical parameters, extreme landforms, fractures, and the presence of magma and other fluids. Because of this high level of heterogeneity and the resulting difficulty to access the wave velocity distribution in the medium, reflection seismic imaging of volcanoes usually suffers from a loss of resolution and contrast. Here, we present a passive seismic imaging technique applied to the case of La Soufrière of Guadeloupe volcano. Inspired by previous works in optics (Badon <em>et al</em>., 2020), in acoustics (Lambert <em>et al</em>., 2020), and recently introduced in seismology (Touma <em>et al</em>., 2020), this technique relies on a matrix approach of passive reflection imaging, which requires only a rough approximation about the medium background velocity. This makes it robust even applied to extreme environments as volcanoes or fault zones. In this approach, the Green’s functions between an array of 76 geophones placed at the surface of the volcano are retrieved by cross-correlation of ambient seismic noise. This set of 2850 inter-element impulse responses forms a reflection matrix. Focusing operations are applied to this reflection matrix at emission and reception to project it in–depth. The focusing process allows to extract body wave components from seismic noise and thus, to retrieve information about reflectivity of in-depth structures. However, at this point, reflectivity images of the subsurface still suffer from phase distortions induced by long-range variations of the seismic velocity. This results in blurred images and hinders appropriate imaging. To overcome these issues, a novel operator is introduced: the distortion matrix. This operator is derived from the focused reflection matrix and connects any point in the medium with the distortion that a wavefront emitted from that point would experience due to heterogeneity. A time-reversal analysis of the distortion matrix allows to retrieve aberrations phase laws and hence to compensate for phase distortions. This correction enables to recover 3D-images of the volcano’s subsurface for the first 10km below the summit with optimized contrast and with an increased resolution. Interestingly, the restored resolution is even at least one half below the diffraction limit imposed by the geophone array angular aperture at the surface. The obtained gain in resolution and contrast allows to unveil internal structures of La Soufrière as hypothetical volcanic vents, magma reservoirs and lateral drainage conduits.</p><p><strong>References</strong></p><p>[Badon <em>et al</em>., 2020] Badon, A., Barolle, V., Irsch, K., Boccara, A. C., Fink, M., and Aubry, A. (2020). Distortion matrix concept for deep optical imaging in scattering media. <em>Science Advances,</em> 6(30).</p><p>[Lambert <em>et al.</em>, 2020] Lambert, W., Cobus, L. A., Frappart, T., Fink, M., and Aubry, A. (2020). Distortion matrix approach for ultrasound imaging of random scattering media. <em>Proceedings of the National Academy of Sciences,</em> 117(26):14645-14656.</p><p>[Touma<em> et al.</em>, 2020] Touma, R., Blondel, T., Derode, A., Campillo, M., & Aubry, A. (2020). A Distortion Matrix Framework for High-Resolution Passive Seismic 3D Imaging: Application to the San Jacinto Fault Zone, California.<em> arXiv preprint arXiv</em>:2008.01608.</p>

DIAGNOSTICS AND TREATMENT OF POISONING WITH THALLIUM

2018 ◽  
pp. 9-15 ◽  
Author(s):  
L. B. Zavaliy ◽  
A. Yu. Simonova ◽  
M. M. Potskhveriya ◽  
Yu. N. Ostapenko ◽  
M. G. Gadzhieva ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Clinical Picture ◽  
Clinical Guidelines ◽  
The Body ◽  
Biological Media ◽  
Pathophysiological Mechanisms ◽  
Thallium Poisoning ◽  
The World

Cases of thallium poisonings are regularly reported in media. In the present work, the world experience in diagnostics and treatment of victims with thallium poisoning has been compiled and summarized, search for clinical guidelines for the diagnostics, treatment and rehabilitation of patients has been carried out. The toxicokinetics and toxicodynamics, as well as pathophysiological mechanisms of thallium influence on the body are described in detail. Toxic and lethal concentrations of poison in biological media, as well as its tropicity to various tissues and body systems were determined. The clinical picture depending on the timing of poisoning and the dose of poison is described in detail. Difficulties of the differential diagnosis are defined. The most interesting cases of criminal and household poisonings with various terms of establishment of the diagnosis, doses of poisoning and outcomes are presented.

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