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Fast-rising population and economic growth are inducing a rapid increase in the energy demand. To date, fossil fuels constitute the primary energy source, but their combustion emits greenhouse gases responsible of global warming. Therefore, developing environment-friendly energy sources is critical. For instance, pyrolysis converts biomass into valuable compounds such as syngas, biochar, and bio-oil, yet produced bio-oil and biogas require further upgrading processes before their use. Current processes include gasification, purification, separation, and catalytic pyrolysis. For syngas synthesis, applying one or a couple of these processes leads to low product yields since they favor the production of bio-oil or biogas. Moreover, tar formation during biomass pyrolysis remains a major technological issue in reactor design. Catalytic reforming is an attractive and efficient method for tar removal via tar oxidation into valuable gases. More importantly, catalytic reforming of pyrolysis volatile products constitutes a promising approach for both tar removal and biogas conversion into syngas. Here, we review the two major catalytic approaches of biomass valorization: catalytic pyrolysis and pyrolysis-catalytic reforming. We demonstrate that the catalytic pyrolysis mainly upgrades bio-oil, while pyrolysis-catalytic efficiently converts biomass into syngas. We analyze the effects of temperature and steam-to-carbon ratio on the products derived from coupling the pyrolysis of agricultural biomass waste to catalytic reforming. Increasing the temperature and steam-to-carbon ratio enhances hydrogen yield. A complete conversion of pyrolysis volatile products into syngas was obtained at 600 °C with steam-to-carbon ratio of 4 for pinewood biomass and nickel catalyst. The use of nickel catalyst supported on lanthana–alumina Ni/La2O3-αAl2O3 for the steam reforming of raw bio-oil produced from pine sawdust pyrolysis enhanced the yields of hydrogen and carbon monoxide, reaching 95% and 93%, respectively, at 700 °C and steam-to-carbon of 15.

International audience; Many sources of heat can emanate from the operation of a rotating machine, and one of which is the friction among the different parts of the ball bearings. Over time, these frictions may lead to a tearing of matter of the rings or on the rolling elements that cause some type of degradation by flaking. Flaking, in turn, produces a repetitive shock as a new source of thermal energy. This work proposes a physical model for the study of the thermal heating of a ball bearing during operation. The resolution of the energy balance is achieved by the Nodal method where both the heating due to friction and the heat induced by the passage of the balls on defect are taken into account. The proposed thermal model is validated through an experimental thermal analysis. The obtained results show that the temperature increases in the position of defect ball ring with increasing rotational speed. The same results are obtained for the influence of radial load.

Resume Objectifs Poser les bases d’une modelisation theorique visant a determiner une loi d’evolution de la temperature cutanee d’un sujet au cours d’une seance de cryotherapie en corps entier. La validation de la demarche scientifique mise en place et l’obtention d’une loi d’evolution thermique temporelle sur la temperature cutanee au cours du choc thermique ouvre une voie large a une modelisation numerique de grande ampleur. Methodes L’etude s’est deroulee dans une prechambre de cryotherapie a −60 °C, sur une duree de trois minutes. Un sujet sportif masculin (1,75 m, 67 kg, IMG 11 %) a participe a cette etude de faisabilite. L’analyse des resultats montre que le corps humain, qui est considere comme un systeme thermique complexe, est regi au cours d’un choc thermique par un ensemble de constantes de temps, pouvant etre considerees comme des valeurs propres a chaque individu. Les lois de comportement obtenues seront utilisees comme conditions aux limites thermiques et implementees dans un code numerique 3D convectoradiatif. L’ambition etant de permettre de donner en tout point du corps humain et a un instant desire sa temperature cutanee, l’objectif a terme est la mise en place de protocoles de cryotherapie personnalises.

Hidradenitis suppurativa (HS) is a chronic, inflammatory, and recurrent skin disease. Surgical excision of wounds appears to be the only curative treatment for the prevention of recurrence of moderate to severe stages. Magnetic resonance imaging (MRI) is a standard reference examination for the detection of HS peri-anal inflammatory fistula. In this case study, the use of real-time medical infrared thermography, in combination with MRI as appropriate imaging, is proposed. The aim is to assist surgeons in the pre- and peri-surgical management of severe perianal hidradenitis suppurativa with the intent to ensure that all diseased lesions were removed during surgery and therefore to limit recurrence. The results show that medical infrared thermography (MIT), coupled with MRI, could be highly effective strategy to address thermally distinguished health tissues and inflammatory sites during excision, as characterised by differential increases in temperature. Medical infrared thermography could be used to check the total excision of inflammatory lesions as a noninvasive method that is not painful, not radiant, and is easily transportable during surgery. Ultimately, this method could be complementary with MRI in providing clinicians with objective data on the status of tissues below the perianal skin surface in the pre- and per-operating management of severe hidradenitis suppurativa.

This article establishes the basics of a theoretical model for the constitutive law that describes the skin temperature and thermolysis heat losses undergone by a subject during a session of whole-body cryotherapy (WBC). This study focuses on the few minutes during which the human body is subjected to a thermal shock. The relationship between skin temperature and thermolysis heat losses during this period is still unknown and have not yet been studied in the context of the whole human body. The analytical approach here is based on the hypothesis that the skin thermal shock during a WBC session can be thermally modelled by the sum of both radiative and free convective heat transfer functions. The validation of this scientific approach and the derivation of temporal evolution thermal laws, both on skin temperature and dissipated thermal power during the thermal shock open many avenues of large scale studies with the aim of proposing individualized cryotherapy protocols as well as protocols intended for target populations. Furthermore, this study shows quantitatively the substantial imbalance between human metabolism and thermolysis during WBC, the explanation of which remains an open question.

In the past decades, the FPA technology has completely and definitively supplanted the scanning infrared cameras; however, if these devices allow better spatial resolution, they induce several calibration problems due to the non-uniformity of the detectors array. For several applications considering the temperature field and not only a mean value (e.g. to realise maps of dissipative sources in thermomechanical engineering, to determine local thermophysical properties…), one can not only consider the global calibration proposed by the manufacturers, and some home-made specific procedure must be developed. Moreover, these built-in calibration are often associated to Non-uniformity correction (NUC) and Bad pixel replacement procedures, that induce a local correlation between pixels, that is incompatible with any data treatment including spatial derivatives (gradient, Laplacian); then, pixel to pixel calibration is the only solution for these kind of applications. In order to help the users needing such a mea...

A detailed understanding of heat transfer and flow is critically important for the pyrolysis of carbonaceous feedstock in fixed bed reactors. In this paper, multimode transport phenomena are simulated by direct pore level simulation on representative digitized samples to retrieve the heat-transfer and pressure-drop properties of highly porous fixed beds of oak-wood chips, which exhibit anisotropic solid-phase tortuosity. A comparison of the direct pore level simulation and simple models of porous media with simple morphologies shows that simple models cannot be used to determine the transport properties of a material with a complex morphology, such as fixed beds of wood chips. Because of drying and devolatilization, the effective thermal conductivity of wood chips decreases with increasing temperature. Heat conduction passes preferentially through the fluid because wood chips have very low thermal conductivity. This study also shows that the shrinking and cracking phenomena resulting from pyrolysis lead to a decrease in the porosity and solid-phase tortuosity and an increase in the specific area. At a high Reynolds number, the pyrolysis also diminishes the permeability but increases the inertial resistance to flow and the interfacial heat transfer.

This article deals with the influence of both morphology and amount of Typha on hygrothermal behavior of a Typha–clay composite for building application. An agromaterial containing the fiber mix of Typha Australis and clay was made in three samples: three fiber mixtures were prepared with different amounts Typha and cut type (transversal or longitudinal). The physical properties of these materials were studied in terms of porosity, apparent and absolute density, thermal conductivity, and hygric properties. Results show a real impact of the Typha fraction type and its volume content on hygrothermal properties of the studied material due to the porosity. The transversal fraction of Typha (80% in volume weight) seems to be the optimal composition for a better hygrothermal behavior.

In the present paper, an application of infrared thermography to inverse heat conduction problems is presented. The study involves the identification of conductive losses at the jaws of a tensile testing machine, which must be assessed in situ, because of variable fastening conditions of the specimen, inducing variable thermal resistances at the jaws. For this purpose, a photo-thermal technique has been developed to identify all the heat exchanges of the sample. An optical excitation, based on a halogen lamp projector, illuminates the specimen in situ on the tensile machine, while the radiative flux excitation is measured using a photodiode. The conductive fluxes are identified, transient and steady, then the equivalent exchange coefficients at the jaws. For this purpose, a direct numerical model by finite differences and an inverse procedure allow to estimate these exchange coefficients. The resolution of the inverse problem is based on the optimization by the conjugate gradient method, of a least square criterion between the temperatures measured by infrared thermography and the temperatures calculated from the direct model.

The pressure ulcers are injuries caused by a constant pressure and without slackening, which damage skin and the subcutaneous flesh, because of the lack of mobility and blood circulation. The injur...

Champagne cork popping out of standard 75 cL bottles was examined through high-speed infrared imaging for three various champagne temperatures (namely, 4, 12, and 18 °C). The cloud of gaseous CO 2 gushing out of the bottleneck while cork popping (invisible in the visible light spectrum) was visualized. Both the volume of gaseous CO 2 gushing out of the bottleneck, and its overall dynamic behavior were found to depend on the champagne temperature. The velocity of the cork popping out of the bottleneck was also measured, and found to logically increase with the champagne temperature. By considering that gases under pressure in the bottleneck experience adiabatic expansion while cork popping, a thermodynamic model was built that accounts for the major physical parameters that influence the volume of gaseous CO 2 gushing out of the bottleneck, its drop of temperature, and its total energy released while cork popping. Only a small fraction of the total energy released while cork popping was found to be converted into the form of cork’s kinetic energy (only about 5%), whatever the champagne temperature.

A standard 75-cl bottle of champagne holds about 5 l of dissolved carbon dioxide (CO2). When pouring champagne into a glass, a significant part of dissolved CO2 desorbs from the liquid phase (Liger-Belair in J Agric Food Chem 53:2788–2802, 2005; Liger-Belair et al. in Chem Soc Rev 37:2490–2511, 2008a). As CO2 is invisible under natural light, its progressive release in the atmosphere was made visible through an infrared (IR) camera equipped with a band-pass filter (Pron et al. in J Vis 13:181–182, 2010). By use of this novel method, the visual tracking of the progressive desorption of dissolved CO2 has been carried out, under standard serving conditions, whether champagne was served into a flute or into a coupe.

In this article, two nondestructive experimental methods are compared in order to evaluate the influence of a singularity, created by geometry, on the damage evolution in the adhesively bonded joints. The first experimental method uses the “back face technique” to measure the disturbances of the strain fields induced by the cracks. The second experimental method uses an infrared focal plane array camera to measure the thermo-elastic field in the geometrical singularity. First of all, both methods are carried out independently: the analysis of the stress/strain and the thermo-graphic analysis. Then, these two methods enabled us to generate a database, the use of which improves the diagnosis of the damage state of the adhesively bonded joints.

International audience; Infrared Focal Plane Array cameras have several aberrations and measurement artefacts with different material origins: lenses, sensors, Read-Out-Circuits of the sensors. The authors' goal is to characterize each artefact separately to obtain more versatile correction procedures and improve the correction accuracy. This paper focuses on some radiometric artefacts associated with variations of measured illuminance. It presents a new correction algorithm dedicated to Narcissus and vignetting effects, which is identified and validated for two different lenses. It also proposes an innovative experimental protocol to detect low-level contrast-induced artefacts. Several R&D cameras and lenses are tested and some present such artefacts, which can not be corrected by traditional pixel-to-pixel methods. Their origins are shown to derive either from the optical system or the Read-Out-Circuit.

The spectral absorption and scattering properties of oakwood are retrieved from the measurements of both the normal-hemispherical reflectance and transmittance in the visible and near-infrared ranges of semi-transparency. We employ two alternative methods for the radiative transfer in wood samples: the modified two-flux approximation and the high-order discrete ordinate method. The modifications of both methods take into account the effect of total internal reflection at both surfaces of the wood samples. The analytical approximate solution of the first method gives very accurate results for the absorption coefficient, but the transport scattering coefficient of wood appeared to be systematically underestimated. Fortunately, this error is between 7% and 12%, and that is acceptable for the estimates. The oakwood samples of four different thicknesses were used in the experiments. The effect of the wood cell orientation appears to be insignificant and can be observed in the reflectance from optically thin samples only. There is a considerable decrease in the transport scattering coefficient of oakwood with the wavelength. This effect is explained by a predominant contribution of micron-sized longitudinal pores in oakwood. The latter is used to develop an approximate theoretical model of scattering based on the rigorous solution for arbitrary-oriented cylindrical pores. The model suggested is in good agreement with the experimental data.

Pouring champagne into a glass is far from being consequenceless with regard to its dissolved CO(2) concentration. Measurements of losses of dissolved CO(2) during champagne serving were done from a bottled Champagne wine initially holding 11.4 +/- 0.1 g L(-1) of dissolved CO(2). Measurements were done at three champagne temperatures (i.e., 4, 12, and 18 degrees C) and for two different ways of serving (i.e., a champagne-like and a beer-like way of serving). The beer-like way of serving champagne was found to impact its concentration of dissolved CO(2) significantly less. Moreover, the higher the champagne temperature is, the higher its loss of dissolved CO(2) during the pouring process, which finally constitutes the first analytical proof that low temperatures prolong the drink's chill and helps it to retain its effervescence during the pouring process. The diffusion coefficient of CO(2) molecules in champagne and champagne viscosity (both strongly temperature-dependent) are suspected to be the two main parameters responsible for such differences. Besides, a recently developed dynamic-tracking technique using IR thermography was also used in order to visualize the cloud of gaseous CO(2) which flows down from champagne during the pouring process, thus visually confirming the strong influence of champagne temperature on its loss of dissolved CO(2).

Thermal resistances between liners and engine blocks are nondestructively studied by photothermal infrared thermography. Under controlled sinusoidal light irradiation, the thermal response of the sample is measured by means of an infrared camera. A numerical lock-in procedure yields amplitude and absolute phase maps of the thermal field periodic component. Then, apart from classical qualitative detection of air layers, a quantitative characterization of thermal resistance becomes available. An analytical modeling, associated with an inverse procedure using the Gauss–Newton parameter estimation method, allows to identify the thermal resistance on academic samples representative of the liner-engine block interface. Simply joined cast iron and aluminum plates present thermal resistances about 2 × 10 −3 K m 2 W −1 . The implementation of a numerical modeling allows to study two-dimensional defects. When the samples are pressed on their periphery, thus straightened, contact resistances ranging from 2 × 10 −4 to 7 × 10 −4 K m 2 W −1 have been measured. Then, the method is applied to liner-engine block interfaces where the thermal resistances fall to about 2 × 10 −5 K m 2 W −1 , matching the values obtained when a cast iron plate is locally pressed against an aluminum plate.

Thermographic lock-in investigation of thermal interaction between a thermal probe used in scanning thermal microscopy and a thin composite sample is used for estimating the relative fraction of heat flux transferred to the sample by conduction through the air and by direct local contact. The latter is determined by vector subtraction of out-of-contact data from in-contact data, for different modulation frequencies. It represents only 8% of the total modulated heat flux dissipated by the probe, and is frequency-independent. The heat transfer by air conduction varies between 23% and 6% for f = 0.2...40 Hz with a broad equivalent heat source radius of r 0.2 mm.

The Hankel integral transform is used to interpret the radial temperature distribution at the surface of a black paint coating on a steel substrate, under irradiation by a modulated laser beam. An inverse method based on the Gauss-Newton algorithm allows the identification of the coating thermal conductivity. To avoid difficulties due to the great number of thermographic data, we present estimations realized directly in the Hankel domain. The black paint coating reveals to be significantly insulating, with a thermal diffusivity of 7.5 10-8 m2.s-1.

This paper presents a measurement method of the thermal dissipation in metallic samples submitted to a plastic strain. Its interest is to extend the field of experimental investigation of the irreversible plastic transformations. The method is applied to the quantification of the thermal dissipation effects associated to the impact of a ball on a thin metallic sample. The final aim of the study consists in proposing a complementary method for controlling and monitoring the shot-peening process. The temperature rise at the rear face after the impact of the ball at the front-face is measured by infrared thermography. Then, the dissipated heat is deduced from the registered thermograms, via a parameter estimation procedure, by a comparison with a specially developed heat diffusion model. The first results presented here show that a preliminary shot-peening of the samples induces a reduction in the energy dissipated during the impact. Then, a specific study has been carried out in order to point out the diminution of the dissipated heat with the number of previous shots.

Temporal, thermal and spatial performances of some FPA cameras have been tested. Different disturbing behaviors related to this recent technology have been pointed out, especially with a view to research and development applications.

The present work consists in the development of a three-dimensional model of heat diffusion in orthotropic media, based on numerical Fourier transforms, and taking into account the extent of the source. This model has been applied, together with a Gauss–Newton parameter estimation procedure, to identify the components of the conductivity tensor of a steel bar under uniaxial loading. Few percent variations of the conductivity components have been observed for applied stresses remaining in the elastic domain.

The plasticization induced by the shot-peening treatment is an exothermic transformation. One can imagine to link the induced residual stress level to the thermal behaviour of the sample during the treatment or, at least, to propose some means of process monitoring control via temperature measurements. Steel samples were submitted to shot-peening under various conditions, both with a compressed air machine and a turbine machine. The temperature of the sample rear face was measured by IR thermography during the treatment. The thermal behaviour of the samples during the treatment have been compared to Almen intensity measurements and to residual stress measurements by the hole-drilling method. We conclude to the feasibility of process monitoring by temperature measurements. More academic experiments are being set up in order to derive quantitative relations between the thermal dissipation and the stress level.

Mechanical stresses, applied or residual, are identified by means of photothermal infra- red thermography. Stresses are detected via their influence on thermophysical properties and more particularly on the thermal conductivity tensor. Because this influence remains weak, a sufficiently accurate identification procedure is needed as well as a significant enhancement of the signal-to-noise ratio, by means of a focal plane array camera.

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ∼52 ± 2 μm deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m−1 K−1 and 26.7 ±1 W m−1 K−1, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10−6 m2 K W−1. The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials.

International audience

A simple glass of champagne or sparkling wine may seem like the acme of frivolity to most people, but in fact, it may rather be considered as a fantastic playground for any fluid physicist or physicochemist. In this chapter, results obtained concerning various steps where the CO₂ molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO₂ impact champagne and sparkling wine science. Some recent investigations, conducted through laser tomography techniques, on ascending bubbles and ascending-bubble-driven flow patterns found in champagne glasses are reported, which illustrate the fine interplay between ascending bubbles and the fluid around under standard tasting conditions. The simultaneous monitoring of gaseous CO₂ and ethanol in the headspace of both a flute and a coupe filled with champagne was reported, depending on whether or not the glass shows effervescence. Both gaseous CO₂ and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between ascending bubbles, ascending-bubble-driven flow patterns, and the release of gaseous CO₂ and volatile organic compounds.

A simple glass of champagne or sparkling wine may seem like the acme of frivolity to most people, but in fact, it may rather be considered as a fantastic playground for any fluid physicist or physicochemist. In this chapter, results obtained concerning various steps where the CO 2 molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO 2 impact champagne and sparkling wine science. Some recent investigations, conducted through laser tomography techniques, on ascending bubbles and ascending-bubble-driven flow patterns found in champagne glasses are reported, which illustrate the fine interplay between ascending bubbles and the fluid around under standard tasting conditions. The simultaneous monitoring of gaseous CO 2 and ethanol in the headspace of both a flute and a coupe filled with champagne was reported, depending on whether or not the glass shows effervescence. Both gaseous CO 2 and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between ascending bubbles, ascending-bubble-driven flow patterns, and the release of gaseous CO 2 and volatile organic compounds.

International audience; This paper aimed to study the feasibility of application of infrared thermography to detect osteoarthritis of the knee and to compare the distribution of skin temperature between participants with osteoarthritis and those without pathology. All tests were conducted at LACM (Laboratory of Mechanical Stresses Analysis) and the gymnasium of the University of Reims Champagne Ardennes. IR thermography was performed using an IR camera. Ten participants with knee osteoarthritis and 12 reference healthy participants without OA participated in this study. Questionnaires were also used. The participants with osteoarthritis of the knee were selected on clinical examination and a series of radiographs. The level of pain was recorded by using a simple verbal scale (0-4). Infrared thermography reveals relevant disease by highlighting asymmetrical behavior in thermal color maps of both knees. Moreover, a linear evolution of skin temperature in the knee area versus time has been found whatever the participant group is in the first stage following a given effort. Results clearly show that the temperature can be regarded as a key parameter for evaluating pain. Thermal images of the knee were taken with an infrared camera. The study shows that with the advantage of being noninvasive and easily repeatable, IRT appears to be a useful tool to detect quantifiable patterns of surface temperatures and predict the singular thermal behavior of this pathology. It also seems that this non-intrusive technique enables to detect the early clinical manifestations of knee OA.

L'utilisation de techniques thermographiques dans le domaine de la mécanique des matériaux est, depuis quelques années, en fort développement dans les laboratoires et dans les centres de recherche et de développement. Cette évolution a été, en grande partie, favorisée par les progrès réalisés en matière de numérisation, de transfert et de traitement des images infrarouges, rendant plus conviviale l'utilisation des nouveaux systèmes thermographiques. Ces systèmes permettent une mesure sans contact de champs de température de surface à des cadences atteignant plusieurs centaines de Hertz pour des images d'environ 80 000 pixels. De façon courante, les variations de température détectables vont de quelques dixièmes à quelques centaines de degré Celsius.

Un modele thermique a ete developpe afin d’identifier les sources de chaleur accompagnant les deformations micro-plastiques intervenant au cours d’un essai de fatigue cyclique. Dans la premiere minute de chaque palier, un modele de barre infinie permet de differer la prise en compte des pertes conductives par les mors. Les sources sont identifiees au fil des paliers de chargement croissant, tout en evitant d’entrer dans le domaine de plasticite macroscopique.

The aim of the present study is to characterize the variations of thermal resistances between liners and engine blocks of cars; a non-destructive evaluation is proposed: photothermal infrared thermography. The thermal response of the sample submitted to a modulated optical stimulation is measured by means of an infrared camera. Then, a numerical lock-in procedure yields both amplitude and absolute phase maps of the thermal field periodic component. On the one hand, an analytical modelling, associated with an inverse procedure using the Gauss-Newton parameter estimation method, allows the identification of the thermal resistance on academic samples, representative of the liner-engine block interface. On the other hand, the implementation of a numerical modelling allows studying two-dimensional defects at the cast iron-aluminium interface. Finally, the method is applied to liner-engine block interfaces. The measured thermal resistances match the values obtained when a cast iron plate and an aluminium plate are pressed together.

FPA infrared cameras are presently at a fast development stage, owing to the rapid increase of the computers performances but, up today, only a few works have dealt with the characterization of such equipments. We present here the results of our first characterization tests, realised with a long wave FPA camera (CEDIP IRC 320-4 LW). Our study was led according to three directions : spatial resolution (in order to point out the correlation between neighbouring pixels), temporal resolution (as a function of the windowing of the matrix) and, finally, thermal resolution.

In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO(2) and ethanol was monitored through micro-gas chromatography (μGC), all along the first 15 minutes following pouring, depending on whether a volume of 100 mL of champagne was served into a flute or into a coupe. The concentration of gaseous CO(2) was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO(2) visualization technique based on infrared imaging was performed, thus confirming this tendency. The influence of champagne temperature was also tested. As could have been expected, lowering the temperature of champagne was found to decrease ethanol vapor concentrations in the headspace of a glass. Nevertheless, and quite surprisingly, this temperature decrease had no impact on the level of gaseous CO(2) found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO(2) escaping the liquid phase into the form of bubbles.

Integral transforms (Laplace, Fourier, Hankel) are widely used to solve the heat diffusion equation. Moreover, it often appears relevant to realize the estimation of thermophysical properties in the transformed space. Here, an analytical model has been developed, leading to a well-posed inverse problem of parameter identification. Two black coatings, a thin black paint layer and an amorphous carbon film, were studied by photothermal infrared thermography. A Hankel transform has been applied on both thermal model and data and the estimation of thermal diffusivity has been achieved in the Hankel space. The inverse problem is formulated as a non-linear least square problem and a Gauss-Newton algorithm is used for the parameter identification.