Search results for "copie"
showing 10 items of 113 documents
Color and multispectral image processing for the detection of inflammatory lesions of the stomach
2019
The work presented in this manuscript is part of the ANR project EMMIE. This project aims to develop an innovative multimodal system for the detection of inflammatory lesions in the stomach. To this purpose, a prototype has been developed to be able to acquire NBI endoscopic images and multispectral images during human's antrum exploration. The prototype is made of a standard endoscope and multispectral images.The prototype can acquire two types of data: NBI images and spectra. These two modalities are processed independently. Common image processing features are used to recognize four kind of diseases: active gastritis, chronic gastritis, metaplasia and atrophy. In addition, visual based f…
In Vitro–In Vivo Fluctuation Spectroscopies
2010
Fluorescence correlation spectroscopy (FCS) was first developed for biophysical studies in analogy with photon scattering correlation spectroscopy. Although it is mainly devoted to the study of freely diffusing particles, FCS is actually able to discern between different kinds of motions, such as diffusion, anomalous diffusion, or drift motions. The frontier application of FCS nowadays is in medical studies both within cells and on the cell membranes, and in the investigation of single molecules in solid matrices. In this field, FCS originated also image correlation spectroscopy methods. The whole field can be unified under the name of fluorescence fluctuation spectroscopy (FFS). We present…
Powder metallurgy processing and deformation characteristics of bulk multimodal nickel
2014
cited By 7; International audience; Spark plasma sintering was used to process bulk nickel samples from a blend of three powder types. The resulting multimodal microstructure was made of coarse (average size ∼ 135 μm) spherical microcrystalline entities (the core) surrounded by a fine-grained matrix (average grain size ∼ 1.5 μm) or a thick rim (the shell) distinguishable from the matrix. Tensile tests revealed yield strength of ∼ 470 MPa that was accompanied by limited ductility (∼ 2.8% plastic strain). Microstructure observation after testing showed debonding at interfaces between the matrix and the coarse entities, but in many instances, shallow dimples within the rim were observed indica…
Femtosecond digital lensless holographic microscopy to image biological samples
2013
The use of femtosecond laser radiation in digital lensless holographic microscopy (DLHM) to image biological samples is presented. A mode-locked Ti:Sa laser that emits ultrashort pulses of 12 fs intensity FWHM, with 800 nm mean wavelength, at 75 MHz repetition rate is used as a light source. For comparison purposes, the light from a light-emitting diode is also used. A section of the head of a drosophila melanogaster fly is studied with both light sources. The experimental results show very different effects of the pinhole size on the spatial resolution with DLHM. Unaware phenomena on the field of the DLHM are analyzed.
Development of direct elemental analysis for process control of nuclear materials manufacturing
2019
In order to optimize the quality control processes of uranium and plutonium metals from nuclear industry production lines, laser-induced breakdown spectroscopy (LIBS) appears as an efficient technique: it enables multi-element, fast and remote chemical analysis that require no sample preparation. Thus, the purpose of our work is to develop this technique towards the quantification of metal impurities in nuclear materials, with an analytical development achieved from surrogate materials. It follows another PhD thesis where a particular spectral band, Vacuum UltraViolet, has been chosen for its performance regarding the detection of several light elements in such materials. However, after per…
Polymer-metal plasmonic waveguide : passive and active components for integrated photonics
2009
Dielectric loaded surface plasmon polariton waveguides (DLSPPWs) enable transmission at a sub-wavelength scale of both electrical and plasmonic (optical waves at the interface between a metal and a dielectric) signals in the same circuitry. Moreover, the use of a polymer as the dielectric load enables the functionalization of DLSPPWs. Therefore, this configuration is of great interest for integrated photonic applications. However, DLSPPWs suffer strong losses due to dissipation into the metal film. We address here the possibility of compensating the losses using a configuration analogous to an optical amplifier. We first set theoretical (effective index model), numerical (differential metho…
Contrôle de nano-antennes optiques par une commande électrique : tuner plasmonique et transduction
2011
Optical nano-antennae are the new class of components to control light/matterinteraction at the nanoscale. These devices are operating in the visible to near infraredpart of the spectrum. The properties of these nano objects are controlled by theform, the size and the material.In the radio frequency domain, the tuner changes dynamically the operatingwavelength of the antenna. In this thesis work, we search to transfer this conceptto the nanoscale. The principle is to change the load impedance of the antenna, i.e.changing the optical index of the dielectric medium around the nano-object. Forthat we used anisotropic liquid cristal molecules. The value of the optical index iscontrolled by appl…
Fabrication and characterization of thermo-plasmonic routers for telecom applications
2013
The Dielectric Loaded Surface Plasmon Polariton Waveguides (DLSPPWs) have recently emerged as a possible solution to carry both optical and electrical signals on- chip. However, in the particular context of optical interconnects, advanced functionalities such as filtering, switching, and routing are required in order to replace in the future the equivalent electronic components which are too much power consumer and also to reduce their footprints. After presenting the interest and limitation of the leakage radiation microscopy method used all along this work, we show several active devices using thermo-sensitive polymers as the dielectric load driven electrically by Joule heating. Then we d…
The second round of Critical Assessment of Automated Structure Determination of Proteins by NMR: CASD-NMR-2013
2015
The second round of the community-wide initiative Critical Assessment of automated Structure Determination of Proteins by NMR (CASD-NMR-2013) comprised ten blind target datasets, consisting of unprocessed spectral data, assigned chemical shift lists and unassigned NOESY peak and RDC lists, that were made available in both curated (i.e. manually refined) or un-curated (i.e. automatically generated) form. Ten structure calculation programs, using fully automated protocols only, generated a total of 164 three-dimensional structures (entries) for the ten targets, sometimes using both curated and un-curated lists to generate multiple entries for a single target. The accuracy of the entries could…
L'ornementation des bracelets de l'âge du Bronze européen : analyse descriptive et perspectives
2013
This paper discusses the ornamental patterns of metal bracelets worn on the arms and legs of people during the European Bronze Age. A method has been specially created to study geometric patterns. Some sets of metal bands (bracelets métalliques) of Bronze Age reach a high level of complexity due to the use of combined patterns in an overall structure. This paper deals with an experimental criterion concerning this phenomenon. The methodology, developed for the purpose i.e. the experimental criterion developed for the purpose of this study, was to extract geometric patterns from the original media. The principle is to release the geometrical compositions of the deformations induced by the mo…