Publications associées à An X-ray computed tomography-based index to characterize the quality of cataclastic carbonate rock samples

A review of materials used in tomographic volumetric additive manufacturing

Christophe Moser, Jorge Andres Madrid Wolff, Riccardo Rizzo

Volumetric additive manufacturing is a novel fabrication method allowing rapid, freeform, layer-less 3D printing. Analogous to computer tomography (CT), the method projects dynamic light patterns into a rotating vat of photosensitive resin. These light pat ...

SPRINGER HEIDELBERG2023

Mechanics of Physical Knots: From Filaments in Contact to Surgical Suturing

Paul Johanns

In this thesis, we study the mechanics of tight physical knots. Knots are omnipresent in surgery, climbing, and sailing, with disastrous consequences when the filament or the rope fails to perform its function. Even if the importance of mechanical analysis ...

EPFL2023

Catalyst Aggregate Size Effect on the Mass Transport Properties of Non-Noble Metal Catalyst Layers for PEMFC Cathodes

Yen-Chun Chen, Vasiliki Tileli, Robin Pierre Alain Girod, Michele Bozzetti, Secil Unsal

Non-noble metal catalysts (NNMCs) are regarded as a promising alternative to the costly Pt-based materials required to catalyze the oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC) cathodes. However, the large diversity of NNMC ...

ELECTROCHEMICAL SOC INC2023

Well-posedness Issues For the Half-Wave Maps Equation With Hyperbolic And Spherical Targets

Yang Liu

This thesis is a study of the global well-posedness of the Cauchy problems for half-wave maps from the Minkowski space of dimension n+1 to the 2-dimensional sphere and the hyperbolic plane. The work is mainly based on the results from Krieger-Sire 17' in ...

EPFL2023

Cross verified independent measurements of correlated bubble property distributions as part of the scale-up of a catalytic bubbling fluidized bed reactor

Philipp Fedor Riechmann

Methanation can be applied as part of a Power-to-Gas (PtG) concept to store renewable electricity. Using a catalytic bubbling fluidized bed (BFB) methanation reactor allows a flexible and economic operation. Properties of bubbles rising through the fluidiz ...

EPFL2022

Bragg edge tomography characterization of additively manufactured 316L steel

Christian Leinenbach, Roland Logé, Nikola Kalentics, Efthymios Polatidis, Markus Strobl

In this work we perform a neutron Bragg edge tomography of stainless steel 316L additive manufacturing samples, one as built via standard laser powder bed fusion, and one using the novel three-dimensional (3D) laser shock peening technique. First, we consi ...

AMER PHYSICAL SOC2022

Exploring the inner workings of the clove hitch knot

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We perform a combined experimental and computational investigation of the clove hitch knot. We develop a physical model for the clove hitch by tying an elastic rod onto a rigid cylinder. In the experiments, we characterize the mechanical performance, geome ...

ELSEVIER2022

The new X-ray/visible microscopy MAXWELL technique for fast three-dimensional nanoimaging with isotropic resolution

Giorgio Margaritondo, Lin Yang

Microscopy by Achromatic X-rays With Emission of Laminar Light (MAXWELL) is a new X-ray/visible technique with attractive characteristics including isotropic resolution in all directions, large-volume imaging and high throughput. An ultrathin, laminar X-ra ...

Nature Portfolio2022

High resolution and three-dimensional printing in complex photosensitive materials

Christophe Moser, Jorge Andres Madrid Wolff, Antoine Vincent Boniface

The present invention is related to a method of volumetric manufacturing a three-dimensional object or article by illuminating a non-transparent and/or absorptive photo-sensitive material with light patterns from multiple angles, comprising the steps of ca ...

2022

A simplified modeling method for multi-particle damper: Validation and application in energy dissipation analysis

Qianqing Wang

Particle dampers have received considerable attention in recent years as a novel damping technique. However, due to its high degree of nonlinearity, no mature damping model has been constructed. This article proposes an equivalent raft model that takes int ...

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD2022

Relative, local and global dimension in complex networks

Alexis Arnaudon

Dimension is a fundamental property of objects and the space in which they are embedded. Yet ideal notions of dimension, as in Euclidean spaces, do not always translate to physical spaces, which can be constrained by boundaries and distorted by inhomogenei ...

Nature Portfolio2022

New Reliability Assessment of MEMS Components under Accumulative Testing for Space Applications

Maxime Auchlin

This dissertation proposes a novel accumulative test method for MEMS-based, commercial off-the-shelves inertial measure units (IMUs) from the automotive field. The need for clarification and augmentation of the corpus of knowledge on MEMS reliability for s ...

EPFL2021

Polarization-sensitive optics diffraction tomography

Demetri Psaltis, Ahmed Ayoub, Joowon Lim, Elizabeth Elena Antoine, Amirhossein Saba Shirvan

Polarization of light has been widely used as a contrast mechanism in two-dimensional (2D) microscopy and also in some three-dimensional (3D) imaging modalities. In this paper, we report the 3D tomographic reconstruction of the refractive index (RI) tensor ...

2021

Three-Dimensional Cubic Barcodes

Martin Vetterli, Golnooshsadat Elhami, Adam James Scholefield

We consider three-dimensional cubic barcodes, consisting of smaller cubes, each built from one of two possible materials and carry one bit of information. To retrieve the information stored in the barcode, we measure a 2-D projection of the barcode using a ...

2022

The shapes of physical trefoil knots

John Maddocks, Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We perform a compare-and-contrast investigation between the equilibrium shapes of physical and ideal trefoil knots, both in closed and open configurations. Ideal knots are purely geometric abstractions for the tightest configuration tied in a perfectly fle ...

2021

Method and system for generating a three-dimensional model based on spherical photogrammetry

Pierre-André Mudry, Frédéric Kaplan, Nils Hamel, Albane Bénédicte Descombes

A computer-implemented method is proposed for creating a three-dimensional model of the environment. The method comprises the steps of planning (105) a trajectory for a moving system carrying an omnidirectional camera comprising a first image sensor facing ...

2021

In-operando dynamic visualization of flow through porous preforms based on X-ray phase contrast imaging

Véronique Michaud, Baris Çaglar, Helena Luisa Teixido Pedarros

Direct visualization is often sought to elucidate flow patterns and validate models to predict the filling kinetics during processes whereby a liquid resin infiltrates a textile porous preform. Here, X-ray phase contrast interferometry is evaluated to imag ...

2021

Method and apparatus for volumetric additive manufacturing of cell-loaded resins

Christophe Moser, Damien Claude-Marie Loterie, Paul Delrot

The present invention is related to a method and apparatus for the volumetric fabrication of three-dimensional objects or articles from photoresponsive materials loaded with scattering particles, by adjusting the refractive index of said photoresponsive ma ...

2021

How to weave a perfect sphere with curved strips

Mark Pauly, Francis Julian Panetta, Pedro Miguel Nunes Pereira de Almeida Reis, Yingying Ren, Tian Chen, Samuel Jean Bernard Poincloux

Triaxial weaving, a craft technique that enables the generation of surfaces with tri-directional arrays of initially straight elastic strips, has long been loved by basket makers and artists seeking a combination of practical and aesthetically-pleasing str ...

American Physical Society2020

Finite Element Modeling of Tight Elastic Knots

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We present a methodology to simulate the mechanics of knots in elastic rods using geometrically nonlinear, full three-dimensional (3D) finite element analysis. We focus on the mechanical behavior of knots in tight configurations, for which the full 3D defo ...

2020