Stephane Serfaty

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Multi-turn split-conductor transmission-line resonators (MSTR) can be designed to operate over a wide range of NMR operating frequencies without lumped tuning capacitors. This architecture constitutes an alternative solution to recent designs proposed for high-Q, thin-film, high-temperature superconducting NMR probes. An advantage is that the resonant(More)
Laser ultrasonic detection is a versatile and highly sensitive tool for the observation of surface waves. In the following study, laser ultrasonic detection is used for the experimental study of spurious normal vibration modes of a disk quartz sensor excited by a voltage pulse. The AT cut crystal (cut of the crystal relative to the the main crystallographic(More)
The behavior of weak gels during their formation singularly attracts attention of dairy products factories. In our study we investigate acidified pre-heated milk gels formation that are fairly often used to product yoghurts. The gel formation requires a tight control of the first step of micelles modification process and the kinetics reaction parameters.(More)
For several years, the Réunion des musées nationaux - Grand-Palais has produced polyester resin reproductions in order to replace marble sculptures that have weakened by outdoor exposure. These objects are made of a complex multilayered polyester composite material including reinforcements to ensure the mechanical strength of the final structure and mineral(More)
The last decades have seen the development of sol-gel (SG) process currently used to develop new materials in a wide range of scientific applications. The SG process leads to an oxide macromolecular network through a sol (liquid phase) to gel transition. To optimize this process, the control of the kinetic of the chemical reaction is required. This kinetic(More)
The paper reports on an original wireless inductive radiofrequency probe dedicated to the distant sensing of the dielectric properties of biological tissues, with noninvasive, non-contact, and easy-to-implement diagnosis of tissues in view. The sensing technique lies on the distant monitoring of a high-quality factor radiofrequency resonator(More)
Class I hybrid poly(N-isopropylacrylamide)/silica hydrogels, PNIPAM/SiO2, were prepared by a new one shot synthesis. In this approach, the free-radical polymerization of vinyl groups of N-isopropylacrylamide (NIPAM) and the hydrolysis-condensation of alkoxy groups of tetramethoxysilane (TMOS) are performed concomitantly using sodium persulfate and(More)
Gelation is a complex reaction that transforms a liquid medium into a solid one: the gel. In gel state, some gel materials (DMAP) have the singular property to ring in an audible frequency range when a pulse is applied. Before the gelation point, there is no transmission of slow waves observed; after the gelation point, the speed of sound in the gel rapidly(More)
This paper deals with a study of the conversion of a Lamb wave at the loaded edge of a plate. An experimental study is performed to know the interaction of surface waves with a viscoelastic material. A Lamb wave is generated by a wedge. At the end of the plate, this wave gives rise to several reflected waves. A first study makes it possible qualitatively to(More)
Laser detection methods allow the investigation of ultrasonic transient phenomena in both space and time dimensions. Used for the experimental investigation of surface wave propagation along a 2D surface, laser ultrasonic leads to three dimensional (3D) space-time signal collections. The classical high resolution signal processing methods or 3D Fourier(More)