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Concept

Gravité artificielle

Publications associées (24)

Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces

François Gallaire, Shahab Eghbali, Simeon Vladimirov Djambov

We study the drainage of a viscous liquid film coating the outside of a solid horizontal cylinder, where gravity acts vertically. We focus on the limit of large Ohnesorge numbers Oh, where inertia is negligible compared to viscous effects. We first study t ...

Amer Physical Soc2024

Microgravity induces overconfidence in perceptual decision-making

Davide Scaramuzza, Christian Pfeiffer, Leyla Loued-Khenissi

Does gravity affect decision-making? This question comes into sharp focus as plans for interplanetary human space missions solidify. In the framework of Bayesian brain theories, gravity encapsulates a strong prior, anchoring agents to a reference frame via ...

Nature Portfolio2023

An Unbiased Method of Measuring the Ratio of Two Data Sets

Jean-Paul Richard Kneib, Huanyuan Shan

In certain cases of astronomical data analysis, the meaningful physical quantity to extract is the ratio R between two data sets. Examples include the lensing ratio, the interloper rate in spectroscopic redshift samples, and the decay rate of gravitational ...

IOP Publishing Ltd2023

Biomechanics at the workplace under hypogravity conditions

Tatiana Maillard

The main goal of my research is to establish guidelines for workplace design based on human biomechanics: specifically sitting workplaces and handling areas in 1/6G-1/3G (Moon, Mars) conditions. Such a workplace could be used in long-term space missions in ...

EPFL2022

Coupling metric-affine gravity to a Higgs-like scalar field

Sebastian Zell

General relativity (GR) exists in different formulations. They are equivalent in pure gravity but generically lead to distinct predictions once matter is included. After a brief overview of various versions of GR, we focus on metric-affine gravity, which a ...

American Physical Society2022

Ultra-high voltage, low power and energy recovering electronics for dielectric elastomer actuators

Raphaël Johannes Charles Mottet

Heart failure is a cardiovascular disease affecting between 1 and 2% of the population of developed countries alone - more than 10 million people - with this number bound to increase due to the ageing of the population. This condition starts to develop its ...

EPFL2022

Matter matters in Einstein-Cartan gravity

Mikhail Chapochnikov, Andrey Shkerin, Georgios Karananas, Sebastian Zell

We study scalar, fermionic and gauge fields coupled nonminimally to gravity in the Einstein-Cartan formulation. We construct a wide class of models with nondynamical torsion whose gravitational spectra comprise only themassless graviton. Eliminating nonpro ...

American Physical Society2021

Characterizing human mobility patterns in rural settings of sub-Saharan Africa

Andrea Rinaldo, Francisco Javier Perez Saez, Theophile Mande

Human mobility is a core component of human behavior and its quantification is critical for understanding its impact on infectious disease transmission, traffic forecasting, access to resources and care, intervention strategies, and migratory flows. When m ...

eLIFE SCIENCES PUBL LTD2021

Thin Liquid Film Dynamics on a Spinning Spheroid

Edouard Boujo

The present work explores the impact of rotation on the dynamics of a thin liquid layer deposited on a spheroid (bi-axial ellipsoid) rotating around its vertical axis. An evolution equation based on the lubrication approximation was derived, which takes in ...

MDPI2021

Manufacturing and Tests of a Tubular Multilayer Dielectric Elastomer Actuator for an Impedance Pump

Yves Perriard, Yoan René Cyrille Civet, Thomas Guillaume Martinez, Jonathan André Jean-Marie Chavanne, Armando Matthieu Walter, Francesco Clavica, David Moser

During the last three decades, the field of electro active polymers (EAP) has seen a rapidly growing interest worldwide. These materials can exhibit many advantages, such as elasticity, high energy density, high dynamics and are often nicknamed artificial ...

2020

Experimental results of gravity currents travelling over a fissured bed

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sara Venuleo

Gravity currents are geophysical flows having large impact on human life and on the environment. The need to prevent and mitigate their negative consequences justifies the multitude of studies carried out to understand their physics. However little has bee ...

2019

Surface tension and viscosity of liquid Pd43Cu27Ni10P20 measured in a levitation device under microgravity

Roland Logé, Antonia Neels, Alex Dommann

Here we present measurements of surface tension and viscosity of the bulk glass-forming alloy Pd43Cu27Ni10P20 performed during containerless processing under reduced gravity. We applied the oscillating drop method in an electromagnetic levitation facility ...

Springer2019

Gravity-Independent Oscillate Boiling

Mohamed Farhat, Outi Supponen

Heat transfer in nucleate boiling relies on the detachment and rise of the boiling bubble, in which gravity plays the dominant role. Previous studies showed that in the absence of gravity, the bubble fails to rise, causing the dryout of the heater and sign ...

SPRINGER2019

Experimental investigation of steel building gravity framing systems under strong earthquake shaking

Dimitrios Lignos

Hybrid simulations were conducted to evaluate the system-level seismic response of a 4-story steel moment frame building and its gravity framing system through various levels of ground motion shaking. The experimental substructure examined in detail corres ...

2019

Potential erosion capacity of gravity currents created by changing initial conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan

We investigate to what extent the initial conditions (in terms of buoyancy and geometry) of saline gravity currents flowing over a horizontal bottom influence their runout and entrainment capacity. In particular, to what extent the effect of the introducti ...

2019

Testing gravity with galaxy-galaxy lensing and redshift-space distortions using CFHT-Stripe 82, CFHTLenS, and BOSS CMASS datasets

Jean-Paul Richard Kneib, Huanyuan Shan

The combination of galaxy-galaxy lensing (GGL) and redshift space distortion of galaxy clustering (RSD) is a privileged technique to test general relativity predictions and break degeneracies between the growth rate of structure parameter f and the amplitu ...

EDP Sciences2019

Image processing and laser measurements for determination of the erosion and deposition of fine sediments by a gravity current

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez, Jessica Zordan

This paper reports a high-resolution, non-intrusive, low-cost technique to measure volumes of erosion and deposition of fine sediments. The combination of two techniques, photography and laser scanning, gives the advantage of simultaneous quantitative esti ...

IOP Publishing2018

Erythrocyte's aging in microgravity highlights how environmental stimuli shape metabolism and morphology

Giovanni Dietler, Giovanni Longo

The determination of the function of cells in zero-gravity conditions is a subject of interest in many different research fields. Due to their metabolic unicity, the characterization of the behaviour of erythrocytes maintained in prolonged microgravity con ...

Nature Research2018

Structure of a dense release produced by varying initial conditions

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan

Buoyancy driven flows such as gravity currents, present in nature and human made applications, are conveyors of particles or dissolved substances for long distances with clear implications for the environment. This transport depends on the triggering condi ...

2018

Gravity-Insensitive Flexure Pivot Oscillators

Simon Nessim Henein, Ilan Vardi, Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan, Lennart Rubbert

Classical mechanical watch plain bearing pivots have frictional losses limiting the quality factor of the hairspring-balance wheel oscillator. Replacement by flexure pivots leads to a drastic reduction in friction and an order of magnitude increase in qual ...

2018