A5008239160- Thermography and Photoacoustic Techniques
- Calibration and Measurement Techniques
- Ultrasonics and Acoustic Wave Propagation
- Thermal properties of materials
- Fire effects on concrete materials
- Infrared Thermography in Medicine
- Plant Pathogenic Bacteria Studies
- Plant pathogens and resistance mechanisms
- Non-Destructive Testing Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Structural Health Monitoring Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Near-Field Optical Microscopy
- Photoacoustic and Ultrasonic Imaging
- Plant-Microbe Interactions and Immunity
- Fatigue and fracture mechanics
- Advanced Sensor and Energy Harvesting Materials
- Infrared Target Detection Methodologies
- Ultrasound and Hyperthermia Applications
- Dental materials and restorations
- Spacecraft Design and Technology
- High Temperature Alloys and Creep
- CCD and CMOS Imaging Sensors
- Lubricants and Their Additives
- Ultrasound Imaging and Elastography
Sorbonne Université
2005-2022
ESPCI Paris
2006-2019
Université Paris Sciences et Lettres
2014-2019
Centre National de la Recherche Scientifique
2001-2019
Laboratoire de Physique et d’Étude des Matériaux
2013-2017
ParisTech
2014-2016
Laboratoire d'Optique Appliquée
2007
École Normale Supérieure - PSL
1996
In integrated circuits, most of the heating is produced in active layers below surface, making thermal measurements extremely difficult. The authors demonstrate that near infrared thermoreflectance can provide imaging inside circuit, through its silicon substrate. use an InGaAs camera with a noncoherent illumination 1.1–1.7μm band allows fast diffraction-limited resolution 1.7μm. A solid immersion lens was then used to further improve 440nm, corresponding effective numerical aperture 2.36.
This paper presents a theoretical approach for the quantitative depth evaluation of linear opened surface cracks by using lock-in infrared thermography. In order to simulate heat flow near crack, three-dimensional simulation model has been developed finite element simulation. We show that, under periodic local thermal excitation in vicinity second spatial derivative amplitude image can provide information on this depth. The influence parameters are discussed optimal characterization defects.
Thick (800 μm) polyvinylidene fluoride/trifluoroethylene (P(VDF-TrFE)) copolymer films for transducer applications are poled under applied voltage at elevated temperatures. By using different heat treatments, poling temperatures, and time, we able to prepare a uniformly film with single resonance peak 1.3 MHz, or nonuniformly two resonances (1.3 2.6 MHz), bimorph structure MHz. The nonuniform polarization which arises from charge injection the cathode is checked by pressure wave propagation...
Abstract Accurate thermal simulations require the knowledge of both conductivity and effusivity samples materials. Most time, specific heat have to be measured with two different setups. In this paper, we will show that a combination experiments done same setup - stimulated infrared thermography allows measure absolute value diffusivity get relative or heat, so determine independently all parameters: conductivity, diffusivity. Keywords: diffusivityconductivityeffusivityspecific heatinfrared camera
Recent advances in infrared imaging have made active thermography an interesting non destructive technique for sub-surface defect detection. Here, we present a method the estimation of depth open surface defects by lock-in thermography, based on relation between crack and Laplacian temperature distribution induced local heating using laser. A comparison to numerical finite element modelling different depths allows accurate determination fatigue Inconel alloy test blocks.
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Summary The establishment of Erwinia amylovora harpin‐induced hypersensitive response (HR) in Nicotiana sylvestris was followed by infra‐red thermography (IRT). Three to four hours after elicitation, the temperature decreased harpin‐infiltrated zone associated stomatal opening. marked drop which reached 2°C and preceded necrosis symptoms for several hours, is thus likely caused higher transpiration. Neither these effects observed a respiratory mutant, affected complex I structure function...
The implementation of space charge measurements based on thermal perturbation thin films requires an improvement the temperature distribution estimation at surface and in depth dielectric materials for getting reliable profile measurements. Absolute variations are needed, both time space. present contribution addresses either thermoelectric or bolometric effects. Both responses have been measured coppercoated silicon nitride layers gold-coated polypropylene heated with a Nd:YAG laser pulse....
Purpose Heating is a major cause of failure in integrated circuits. The authors have designed thermoreflectance‐based systems operating at various wavelengths order to obtain temperature images. This paper aims explore the possibilities each wavelength range and detail charge coupled device (CCD)‐based thermal imaging tools dedicated high‐resolution inspection Design/methodology/approach Thermoreflectance non‐contact optical method using local reflectivity variations induced by heating infer...
Two original methods using lock-in thermography with a laser excitation are proposed for the estimation without contact of open crack depths in metal. The first uses modulated punctual thermal source and is well suited study complicated structures. In second, continuous moving allows to scan homogeneous Each method relies on heat diffusion modifications induced by located area synchronised source. signature extracted amplitude surface temperature images various modulation frequencies or...
Abstract The LIMM and PWP methods are well known which allow for non-destructive determination of the homogeneity permanent polarization distribution inside dielectric samples. In this paper, measurements made on PVDF, ceramic copolymer samples reported electronic instrumental corrections presented. We clearly observe a non-polarized area near surfaces different spatial distributions Simulations based data lead to better profile throughout sample, with increased resolution.
The evaluation of a dental restoration in non-invasive way is paramount importance clinical practice. aim this study was to assess the minimum detectable open crack at cavity–restorative material interface by lock-in thermography technique, laser intensities which are safe for living teeth. For analysis interface, 18 box-type class V standardized cavities were prepared on facial and oral surfaces each tooth, with coronal margins enamel apical dentine. preparations restored Giomer Beautifil...
The feasibility of transcranial high-intensity focused-ultrasound (HIFU) therapy within the brain relies on ability to transmit ultrasound through skull bone at relatively high power. Absorption may cause important temperature rises, and is therefore an parameter control. Ultrasonic measurements have shown that beam undergoes a significant attenuation when propagating skull, with values order 10 20 dB/cm/MHz. To predict rise from such values, it fundamental weigh relative role absorption...