Concept

Speed of sound

Related publications (122)

Wind Estimation with Multirotor UAVs

Unmanned Aerial Vehicles (UAVs) have benefited from a tremendous increase in popularity over the past decade, which has inspired their application toward many novel and unique use cases. One of them is the use of UAVs in meteorological research, in particu ...

2022

Micromechanical Modelling of Elastic Wave Velocity Variations for Intact Brittle Rocks

Antoine Guggisberg

Until now, the micromechanical wing crack model of Ashby & Sammis 1990 describing the brittle field of rocks has only been used for failure predictions. However, it gives relevant information regarding the crack opening process, so this model is extended t ...

2021

Nonlinear study on a rigid rotor supported by herringbone grooved gas bearings: Theory and validation

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig, Wanhui Liu

The nonlinear behavior of a rigid rotor supported by herringbone grooved journal gas bearings (HGJBs) was investigated in this study. The two-dimensional narrow groove theory (2D-NGT) was adopted to model the HGJBs. A set of integrated rotor-bearing state ...

2021

Frictional behaviour of carbonate bearing faults at brittle-ductile transition

Marie Estelle Solange Violay, Mathias Alexandre David Lebihain, Carolina Giorgetti, Francesco Figura

One of the most alarming recent findings in geo-science is the dramatic rise in the rate of humaninduced earthquakes in the past decade. This is due to the fluid injection or extraction in deep reservoirs for hydrocarbon production, wastewater and CO2 stor ...

2021

Directional Cross-Correlation for Improved Aberration Phase Estimation in Pulse-Echo Speed-of-Sound Imaging

Jean-Philippe Thiran, Samuel Denys Beuret, Simon Canales

There has been a recent surge in methods targeting the recovery of a speed-of-sound map from pulse-echo ultrasound measurements. We focused in this work on a particular technique and identified a drawback shared by similar methods - namely the necessity of ...

IEEE2021

Unstable tilting motion of flexibly supported gas bearing bushings

Jürg Alexander Schiffmann, Philipp Kaspar Bättig

This paper presents measurements of the motion amplitudes from flexibly supported Herringbone Grooved Journal Bearing bushings. Measurements taken in four locations on the flexibly supported bearing bushing enable the distinction between the radial and the ...

2021

Stiff, Strong, Tough, and Highly Stretchable Hydrogels Based on Dual Stimuli-Responsive Semicrystalline Poly(urethane–urea) Copolymers

Nicolas Candau, Oguzhan Oguz, Adrien Julien Demongeot

There has been a considerable interest in developing stiff, strong, tough, and highly stretchable hydrogels in various fields of science and technology including biomedical and sensing applications. However, simultaneous optimization of stiffness, strength ...

2021

Stability and Unbalance Analysis of Rigid Rotors Supported by Spiral Groove Bearings: Comparison of Different Approaches

Jürg Alexander Schiffmann, Elia Iseli

The dynamic behavior of spiral-grooved gas bearing supported four degrees-of-freedom (DOF) rotors is investigated by means of linearized bearing force coefficients and full time-integrated transient analysis. The transient method consists of a state-space ...

2021

Development of Impact-Echo Multitransducer Device for Automated Concrete Homogeneity Assessment

Bartlomiej Wojciech Sawicki

A combination of multiple nondestructive testing (NDT) methods speeds up the assessmentof concrete and increases the precision. This is why the UIR-Scanner was developed at WarsawUniversity of Technology. The scanner uses an Impact-Echo (IE) method with a ...

2021

The Role of Geometrical Parameters in the Lubrication of the Swiss Lever Escapement

Stefano Mischler

The lubrication regimes of a contact pair escapement-ruby pallet of a Swiss lever escapement have been investigated combining the theory of fluid lubrication with a well-established kinematic and inverse dynamic multibody model. The kinematic analytical re ...

2021

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