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17094
01/04/2018

Design and evaluation of a smart insole: application for continuous monitoring of frail people at home

Y.CHARLON, E.CAMPO, D.BRULIN

S4M

Revue Scientifique : Expert Systems with Applications, Vol.95, pp.57-71, Avril 2018, DOI https://doi.org/10.1016/j.eswa.2017.11.024 , N° 17094

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Abstract

The objectives of this work are to develop a technological solution designed to support active aging of frail older individuals and to conduct a first evaluation of the devices. We wish to bring a reflection in the field of connected health by setting up a remote medical follow-up. In this context, the connected object presented in this article aims at implementation a longitudinal follow-up of the walk by a health professional. Continuous remote data analysis applies behavior learning methods by modeling walking habits and allows the detection of deviations by application of thresholds defined by the expert. We propose an instrumented shoe insole to provide such monitoring (number of steps, distance covered and gait speed). In this perspective, we designed a low power microelectronic device integrated into the thickness of an insole in order to demonstrate the technical feasibility of such a device in laboratory and in living conditions. The project called “FOOT-TEST” is funded by the DIRECCTE of the Midi-Pyrenees Region in France. This project brought together a manufacturer who specializes in the design of foot-care systems, geriatricians and our laboratory specialized in electronics to propose a technical solution adapted to frail individuals. Two smart insole prototypes have been produced and a first evaluation of the smart insole in real use conditions has been performed. According to user feedback, the smart insole seems to be much easier to use than commercial connected pedometers. Moreover, in terms of performance, the smart insole provides better results. In this paper, we present specifications of the device, technological choices and the design of two versions of the smart insole, methods used to measure desired settings, a first evaluation of the system and, finally, preliminary conclusions and work in progress.

141595
18069
25/02/2018

Evaporation with the formation of chains of liquid bridges

C.CHEN, P.JOSEPH, S.GEOFFROY, M.PRAT, P.DURU

IMFT, MILE, LMDC

Revue Scientifique : Journal of Fluid Mechanics, Vol.837, pp.703-728, Février 2018 , N° 18069

Lien : https://hal.laas.fr/hal-01701199

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The objective of the present work is to study the drying of a quasi-2D model porous medium, thereafter called micromodel, initially filled with a pure liquid. The micromodel consists of cylinders measuring 50 µm in both height and diameter, radially arranged as a set of neighbouring spirals and sandwiched between two horizontal, flat plates. As drying proceeds, air invades the pore space and elongated liquid films trapped by capillary forces form along the spirals. These films consist of " chains " of liquid bridges connecting neighbouring cylinders. They provide an hydraulic connectivity between the central, bulk liquid cluster and the external rim of the cylinders pattern, where evaporation is taking place during a first constant evaporation-rate drying stage. The first goal of the present paper is to describe experimentally the phase distribution during drying, notably the liquid films evolution, which controls the evaporation kinetics (e.g. the depinning of the films from the external rim signs the end of the constant evaporation rate period). Then, a visco-capillary model for the drying process is presented. It is based on numerical simulations of a liquid film capillary shape and of the viscous flow within a film. The model shows a reasonably good agreement with the experimental data. Thus, the present study is a step towards direct modelling of the films effect on the drying of more complex porous media (e.g. packing of beads) and should be of interest for multiphase flow applications in porous media, involving transport within liquid films.

142845
18017
08/02/2018

Simulation of Single Particle Displacement Damage in Silicon – Part III: First Principles Characterization of Defect Properties

A.JAY, A.HEMERYCK, N.RICHARD, L.MARTIN SAMOS, M.RAINE, A.LE ROCH, N.MOUSSEAU, V.GOIFFON, P.PAILLET, P.PAILLET, M.GAILLARDIN, P.MAGNAN

ISAE, M3, CEA-DAM, UNG, UdeM

Revue Scientifique : IEEE Transactions on Nuclear Science, 8p., Février 2018, DOI 10.1109/TNS.2018.2790843 , N° 18017

Lien : https://hal.archives-ouvertes.fr/hal-01685608

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Abstract

A first principles study of the defects generated by displacement cascades in silicon is performed. This work is particularly focused on two defect configurations; the di-vacancy and the tri-interstitial, both identified in previous Molecular Dynamics (MD) and kinetic Activation Relaxation Technique (k-ART) simulations [1, 2]. By combining structural, energy and migration properties evaluated within the framework of the standard Density Functional Theory (DFT) and electronic properties calculated within the G 0 W 0 approximation, a reconstruction of the corresponding thermally-activated electrical signal generated by each defect is obtained. Their contribution to Dark Current (DC) and Dark Current Random Telegraph Signal (DC-RTS) measured in image sensors is then discussed.

142335
17515
07/02/2018

Lab-on-Chip for DNA Analysis With Resolution Length of 3 bp and Concentration of 10 nM

B.CHAMI, M.SOCOL, R.MALBEC, A.BANCAUD

MILE, MICA

Affiche/Poster : MICROFLUIDICS2017 - Ecole thématique ( ) 2017 du 25 juin au 30 juin 2017, Carcans Maubuisson (France), Février 2018, 1p. , N° 17515

Lien : https://hal.archives-ouvertes.fr/hal-01686185

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142319
18012
30/01/2018

Accelerated transport of particles in confined channels with high roughness amplitude

H.RANCHON, J.CACHEUX, B.REIG, O.LIOT, P.TEERAPANICH, T.LEICHLE, P.JOSEPH, A.BANCAUD

MILE, MEMS, TEAM

Revue Scientifique : Langmuir, Vol.34, N°4, pp.1394-1399, Janvier 2018 , N° 18012

Lien : https://hal.archives-ouvertes.fr/hal-01682628

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We investigate the pressure-driven transport of particles 200 or 300 nm in diameter in shallow microfluidic channels ∼1 μm in height with a bottom wall characterized by a high roughness amplitude of ∼100 nm. This study starts with the description of an assay to generate cracks in hydrophilic thin polymer films together with a structural characterization of these corrugations. Microfluidic chips of variable height are then assembled on top of these rough surfaces, and the transport of particles is assessed by measuring the velocity distribution function for a set of pressure drops. We specifically detect anomalous transport properties for rough surfaces. The maximum particle velocity at the centerline of the channel is comparable to that obtained with smooth surfaces, but the average particle velocity increases nonlinearly with the flow rate. We suggest that the change in the boundary condition at the rough wall is not sufficient to account for our data and that the occurrence of contacts between the particle and the surface transports the particle away from the wall and speeds up its motion. We finally draw perspectives for the separation by field-flow fractionation.

142202
17312
01/01/2018

Growth, stability and decomposition of Mg 2 Si ultra-thin films on Si (100)

B.SARPI, R.ZIRMI, M.PUTERO, M.BOUSLAMA, A.HEMERYCK, S.VIZZINI

IM2NP, LATAGE, LSM, M3

Revue Scientifique : Applied Surface Science, Vol.423, N°Part B, pp.522-527, Janvier 2018 , N° 17312

Lien : https://hal.laas.fr/hal-01583845

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Abstract

Using Auger Electron Spectroscopy (AES), Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Low Energy Electron Diffraction (LEED), we report an in-situ study of amorphous magnesium silicide (Mg2Si) ultra-thin films grown by thermally enhanced solid-phase reaction of few Mg monolayers deposited at room temperature (RT) on a Si(100) surface. Silicidation of magnesium films can be achieved in the nanometric thickness range with high chemical purity and a high thermal stability after annealing at 150 °C, before reaching a regime of magnesium desorption for temperatures higher than 350 °C. The thermally enhanced reaction of one Mg monolayer (ML) results in the appearance of Mg2Si nanometric crystallites leaving the silicon surface partially uncovered. For thicker Mg deposition nevertheless, continuous 2D silicide films are formed with a volcano shape surface topography characteristic up to 4 Mg MLs. Due to high reactivity between magnesium and oxygen species, the thermal oxidation process in which a thin Mg2Si film is fully decomposed (0.75 eV band gap) into a magnesium oxide layer (6–8 eV band gap) is also reported.

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18026
01/01/2018

Ion Transport and Precipitation Kinetics as Key Aspects of Stress Generation on Pore Walls Induced by Salt Crystallization

A.NAILLON, P.JOSEPH, M.PRAT

MILE, IMFT

Revue Scientifique : Physical Review Letters, Vol.120, N°3, 034502p., Janvier 2018 , N° 18026

Lien : https://hal.laas.fr/hal-01700814

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The stress generation on pore walls due to the growth of a sodium chloride crystal in a confined aqueous solution is studied from evaporation experiments in microfluidic channels in conjunction with numerical computations of crystal growth. The study indicates that the stress build-up on the pore walls as the result of the crystal growth is a highly transient process taking place over a very short period of time (in less than 1s in our experiments). The analysis makes clear that what matters for the stress generation is not the maximum supersaturation at the onset of the crystal growth but the supersaturation at the interface between the solution and the crystal when the latter is about to be confined between the pore walls. It is shown that the stress generation can be characterized with a simple stress diagram involving the pore aspect ratio and the Damkhöler number characterizing the competition between the precipitation reaction kinetics and the ion transport towards the growing crystal. This opens up the route for a better understanding of the damage of porous materials induced by salt crystallization, an important issue in earth sciences, reservoir engineering and civil engineering.

142544
16314
11/12/2017

Analysis of DNA replication by optical mapping in nanochannels

J.LACROIX, S.PELOFY, MC.BLATCHE, M.J.PILLAIRE, S.HUET, C.CHAPUIS, J.S.HOFFMAN, A.BANCAUD

MILE, I2C, TOUCAN, Rennes

Revue Scientifique : Small, Vol.12, N°43, pp.5963-5970, Décembre 2017, DOI 10.1002/smll.201503795 , N° 16314

Lien : https://hal.archives-ouvertes.fr/hal-01384735

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Abstract

DNA replication is essential to maintain genome integrity in S phase of the cell division cycle. Accumulation of stalled replication forks is a major source of genetic instability, and likely constitutes a key driver of tumorigenesis. The mechanisms of regulation of replication fork progression have therefore been extensively investigated, in particular with DNA combing, an optical mapping technique that allows the stretching of single molecules and the mapping of active region for DNA synthesis by fluorescence microscopy. DNA linearization in nanochannels has been successfully used to probe genomic information patterns along single chromosomes, and has been proposed to be a competitive alternative to DNA combing. Yet this conjecture remains to be confirmed experimentally. Here, two complementary techniques are established to detect the genomic distribution of tracks of newly synthesized DNA in human cells by optical mapping in nanochannels. Their respective advantages and limitations are compared, and applied them to detect deregulations of the replication program induced by the antitumor drug hydroxyurea. The developments here thus broaden the field of applications accessible to nanofluidic technologies, and can be used in the future as part for molecular diagnostics in the context of high throughput cancer drug screening.

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17097
11/12/2017

Approche méthodologique pluridisciplinaire pour l'observation de la prise en main de technologies numériques par des personnes âgées

N.VIGOUROUX, E.CAMPO, C.GRIMAUD, F.VELLA, E.BOUGEOIS

IRIT-UPS, S4M, AG2R La Mondiale, LERASS

Ouvrage (contribution) : Des services à la personne à la silver économie Comment accompagner le vieillissement de la population à domicile sur les territoires aujourd'hui et demain ?, éditions ems, N°ISBN 9791094033142, Décembre 2017, Chapitre 5, pp.103-120 , N° 17097

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Résumé

Les enjeux liés au vieillissement de la population sont désormais considérables pour notre pays puisque à l’horizon 2060, les personnes de 60 ans et plus pourraient représenter près de 30 % de la population totale selon Blanpain et Chardon (2010), soit plus de 20 millions d’individus. Même si l’espérance de vie et la qualité de vie se sont très fortement améliorées par rapport à l’après-guerre, cela pose et va poser plusieurs questions notamment : comment permettre le maintien à domicile des personnes âgées, de celles qui sont en perte d’autonomie voire dépendantes ? Le secteur des services à la personne se situe à un moment charnière de son évolution, en raison de la mise en oeuvre de la loi relative à l’Adaptation de la Société au Vieillissement (ASV) au cours de l’année 2016, laquelle cherche à apporter des réponses aux transformations démographiques actuellement en cours dans notre pays. Compte tenu de la complexité des enjeux que le vieillissement de la population soulève, il nous a semblé nécessaire de pouvoir croiser différents points de vue, compétences et expérimentations en suscitant un dialogue entre des disciplines scientifiques variées mais aussi avec des praticiens "du domicile". Dans ce sens, nous avons mis en place un comité éditorial qui a réuni 33 enseignants-chercheurs et professionnels, dont l’expertise a permis de couvrir les principales problématiques rencontrées par le secteur des services à la personne et, de manière plus large, la Silver Economie, gage, par là même, de la rigueur et de la qualité des chapitres présentés dans ce livre. Dans cet ouvrage, vous trouverez 8 chapitres qui ont été rédigés par 21 auteurs professionnels, enseignants-chercheurs et/ou docteurs concernant cinq grandes thématiques qui sont : les conditions de travail et la conciliation emploi-famille pour les métiers d’intervention au Québec ; la construction de parcours et la gouvernance de réseaux sur les territoires ; la professionnalisation de l’encadrement et du management des structures de services à la personne ; le recours aux gérontechnologies pour favoriser le maintien à domicile ; les limites d’appropriation voire les questions déontologiques, éthiques et juridiques que pose l’utilisation des gérontechnologies au domicile.

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17438
08/12/2017

Pore cross-talk in colloidal filtration

O.LIOT, S.AKASH, P.BACCHIN, P.DURU, J.MORRIS, P.JOSEPH

MILE, LGC, IMFT, Levich Institute

Rapport LAAS N°17438, Décembre 2017, 7p.

Lien : https://hal.laas.fr/hal-01651843

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Abstract

Blockage of pores by particles is found in numerous industrial and natural processes, including filtration and oil extraction. We present experimental results of filtration through a linear array of ten channels with one dimension which is sub-micron. These silicon-glass nanoslits serve as model pores, through which a dilute dispersion of Brownian polystyrene spheres flows. The clog growth rate at fixed differential pressure is shown to systematically increase with the number of saturated (entirely clogged) pores, indicating that there is an interaction or " cross-talk " between the pores. This observation is interpreted using a model proposed here, based on the concept that the residual permeability allows a clog to act as a filter. A clogged pore is thus the source of a local increase of particle concentration adjacent to the pore, which then diffuses towards other pores. This phenomenon, evidenced and modelled here in one dimension, should be at play in two-dimensional membranes.

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