arXiv subjects

G. Daniel

Publications and source records attributed to G. Daniel.

3 recordsLinked to original sources

arXiv2020

Microtomography on the ANATOMIX beamline at Synchrotron SOLEIL

The ANATOMIX beamline at Synchrotron SOLEIL, operational since 2018, is dedicated to hard X-ray full-field tomography techniques. Operating in a range of photon energies from approximately 5 to 50 keV, it offers both parallel-beam projection microtomography, in absorption and phase contrast, and nanotomography using a zone-plate transmission X-ray microscope. With these methods, the beamline covers a range of spatial resolution from 20 nm to 20 $\mu$m, expressed in terms of useful pixel size. The variable beam size of up to 40 mm allows users to image large objects. Here we describe the microtomography instrumentation of the beamline.

physics.ins-det↗

arXiv2019

Model reduction methodology for computational simulations of endovascular repair

Endovascular aneurysm repair (EVAR) is a current alternative treatment for thoracic and abdominal aortic aneurysms, but is still sometimes compromised by possible complications such as device migration or endoleaks. In order to assist clinicians in preventing these complications, finite element analysis (FEA) is a promising tool. However, the strong material and geometrical nonlinearities added to the complex multiple contacts result in costly finite-element models. To reduce this computational cost, we establish here an alternative and systematic methodology to simplify the computational simulations of stent-grafts (SG) based on FEA. The model reduction methodology relies on equivalent shell models with appropriate geometrical and mechanical parameters. It simplifies significantly the contact interactions but still shows very good agreement with a complete reference finite-element model. Finally, the computational time for EVAR simulations is reduced of a factor 6 to 10. An application is shown for the deployment of a SG during thoracic endovascular repair, showing that the developed methodology is both effective and accurate to determine the final position of the deployed SG inside the aneurysm.

physics.med-ph↗

arXiv2008

Econophysics: historical perspectives

Econophysics embodies the recent upsurge of interest by physicists into financial economics, driven by the availability of large amount of data, job shortage in physics and the possibility of applying many-body techniques developed in statistical and theoretical physics to the understanding of the self-organizing economy. This brief historical survey emphasizes that Econophysics has many historical precursors, and is in fact rooted in a continuous cross-fertilization between economics and physics that has been active in the last centuries.

q-fin.GN↗