Grenoble Institute of Technology

About: Grenoble Institute of Technology is a education organization based out in Grenoble, France. It is known for research contribution in the topics: Hyperspectral imaging & Geology. The organization has 3427 authors who have published 5345 publications receiving 137158 citations. The organization is also known as: Grenoble INP.

Preparation of aqueous anionic poly-(urethane-urea) dispersions: Influence of the nature and proportion of the urethane groups on the dispersion and polymer properties

Abstract: Aqueous poly(urethane‐urea) dispersions were prepared by the prepolymer mixing technique without the use of any organic solvent. Most of the work focused on the use of two aliphatic diisocyanates (α,α, α', α'‐tetramethyl‐1,3‐xylylene diisocyanate and isophorone diisocyanate) and two macrodiols (α,ω‐poly(propylene glycol) (Mn = 1000) and α,ω‐poly(caprolactone) (Mn = 530)) in conjunction with a fixed proportion of emulsifying agent (dimethylol propionic acid, neutralized with triethyl amine) and the same chain extender (1,2‐ethylene diamine). The properties of both the dispersions and the dried polymer films, as well as those of some model prepolymers, were characterized as a function of the initial composition to establish criteria leading to the optimized performance in terms of dispersion stability and particle size and polymer properties. The most important parameter in this search was found to be the [NCO]/[OH] ratio, which gave the best results when it approached a value of 2.

Design options for hetero-junction tunnel FETs with high on current and steep sub-threshold voltage slope

Abstract: This work presents a systematic design study of nanowire Tunnel-FETs at LG=17nm employing a 3D Poisson-NEGF solver based on a 8×8 k·p Hamiltonian and including phonon scattering. In particular: (a) we revisit the design of GaSb-InAs based hetero-junction tunnel-FETs showing that this system is unlikely to yield a broken bangap profile at the very narrow features necessary for a good sub-VT slope value; (b) we propose new design options for hetero-junction tunnel-FETs, relying on the use of strain and of a graded molar fraction (xM) in AlxMGa(1-xM)Sb, which improve remarkably on current preserving optimal sub-VT slopes; (c) we show that interface defects can frustrate any design strategy aiming at sub-VT slope values below 60mV/dec.

Rigidity-Patterned Polyelectrolyte Films to Control Myoblast Cell Adhesion and Spatial Organization

Abstract: In vivo, cells are sensitive to the stiffness of their microenvironment and to the spatial organization of the stiffness. In vitro studies of this phenomenon can help to better understand the mechanisms of the cell response to spatial variations of the matrix stiffness. Here, polelyelectrolyte multilayer films made of poly(l-lysine) and a photoreactive hyaluronan derivative are designed. These films can be photo-crosslinked through a photomask to create spatial patterns of rigidity. Quartz substrates incorporating a chromium mask are prepared to expose selectively the film to UV light (in a physiological buffer), without any direct contact between the photomask and the soft film. It is shown that these micropatterns are chemically homogeneous and flat, without any preferential adsorption of adhesive proteins. Three groups of pattern geometries differing by their shape (circles or lines), size (from 2 to 100 μm), or interspacing distance between the motifs are used to study the adhesion and spatial organization of myoblast cells. The results pave the way for the study of the different steps of myoblast fusion in response to matrix rigidity in well-defined geometrical conditions.

A Global Study of a Contactless Energy Transfer System: Analytical Design, Virtual Prototyping, and Experimental Validation

Abstract: This paper presents a design methodology dedicated to a two-winding transformer with large air gap and magnetic cores. To design this kind of components, it is necessary to consider the influence of inductive parameters on electrical magnitudes and the converter, which supplies this magnetic device. Indeed, this kind of a magnetic device has a large leakage inductance and a small magnetizing inductance. Therefore, to transfer the desired power, the transformer needs important reactive energy to magnetize magnetic core and to provide leakage flux. Like inductive parameters can be determined only when geometry is known, sizing has to be iterative. Moreover, resonant converters can be used to compensate inductive behavior, but modify electrical constraints of the transformer. A robust algorithm of design and all necessary tools are presented in order to make it easier to size such components. After the analytical design, 3-D FEM simulations and experimental measurements have been carried out in order to validate the theoretical study. Moreover, the power electronics converter has been optimized in order to improve the efficiency of power transfer. A prototype of 1.6 kW 100 kHz with an air gap of 6 mm has been realized with its converter. The global efficiency is 93.3%.

Automatic fish sounds classification

Abstract: The work presented in this paper focuses on the use of acoustic systems for passive acoustic monitoring of ocean vitality for fish populations. Specifically, it focuses on the use of acoustic systems for passive acoustic monitoring of ocean vitality for fish populations. To this end, various indicators can be used to monitor marine areas such as both the geographical and temporal evolution of fish populations. A discriminative model is built using supervised machine learning (random-forest and support-vector machines). Each acquisition is represented in a feature space, in which the patterns belonging to different semantic classes are as separable as possible. The set of features proposed for describing the acquisitions come from an extensive state of the art in various domains in which classification of acoustic signals is performed, including speech, music, and environmental acoustics. Furthermore, this study proposes to extract features from three representations of the data (time, frequency, and cepstral domains). The proposed classification scheme is tested on real fish sounds recorded on several areas, and achieves 96.9% correct classification compared to 72.5% when using reference state of the art features as descriptors. The classification scheme is also validated on continuous underwater recordings, thereby illustrating that it can be used to both detect and classify fish sounds in operational scenarios.