Viscoelastic dynamics of a soft strip subject to a large deformation.

To produce sounds, we adjust the tension of our vocal folds to shape their properties and control the pitch. This efficient mechanism offers inspiration for designing reconfigurable materials and adaptable soft robots. However, understanding how flexible structures respond to a significant static strain is not straightforward.

Soft elastomers: A playground for guided waves.

Mechanical waves propagating in soft materials play an important role in physiology. They can be natural, such as the cochlear wave in the inner ear of mammalians, or controlled, such as in elastography in the context of medical imaging. In a recent study, Lanoy, Lemoult, Eddi, and Prada [Proc.

Dirac cones and chiral selection of elastic waves in a soft strip.

We study the propagation of in-plane elastic waves in a soft thin strip, a specific geometrical and mechanical hybrid framework which we expect to exhibit a Dirac-like cone. We separate the low frequencies guided modes (typically 100 Hz for a 1-cm-wide strip) and obtain experimentally the full dispersion diagram. Dirac cones are evidenced together with other remarkable wave phenomena such as negative wave velocity or pseudo-zero group velocity (ZGV).

A PDMS-based broadband acoustic impedance matched material for underwater applications.

Having a material that is matched in acoustic impedance with the surrounding medium is a considerable asset for many underwater acoustic applications. In this work, impedance matching is achieved by dispersing small, deeply subwavelength sized particles in a soft matrix, and the appropriate concentration is determined with the help of Coherent Potential Approximation and Waterman & Truell models. We show experimentally the validity of the models using mixtures of Polydimethylsiloxane (PDMS) and TiO particles.

[Cervical aortic arch. Apropos of a case].

A new case of left cervical aorta is described, affecting a 12-year-old girl. Haemodynamic, CT scan and radiological investigations are described. The only associated abnormality in the present case was hypoplasia of the left vertebral artery.

Medically equipped emergency ambulance units at "Hôpital Civil de Charleroi". Four years' activity.

In narrow collaboration with the so-called "900 Service", the civil Hospital of Charleroi provides, since 1971, medical attendance for two emergency medical aid flying squads. Five hospital doctors belonging to this "900 Service" alternately assume, night and day, such responsibilities. Their background is reanimation anesthesia.