Hervé Pron

On the Losses of Dissolved CO2 during Champagne Serving

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 drinks 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).

Focal plane array infrared cameras as research tools

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.

Monitoring Gaseous CO2 and Ethanol above Champagne Glasses: Flute versus Coupe, and the Role of Temperature

In champagne tasting, gaseous CO2 and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO2 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 CO2 was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO2 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 CO2 found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO2 escaping the liquid phase into the form of bubbles.

Thermal Conductivity Profile Determination in Proton-Irradiated ZrC by Spatial and Frequency Scanning Thermal Wave Methods

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 con...

Dynamic-tracking desorption of CO2 in Champagne wine using infrared thermography

Graphical Abstract

Parameter identification in the Hankel space

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.

Medical Infrared Thermography assistance in the surgical treatment of axillary Hidradenitis Suppurativa: A case report

Highlights • We used a Medical Infrared Thermography tool to assist the surgeon in the surgical treatment of Hidradenitis Suppurativa inflammatory disease.• The advantage of the medical infrared thermography is to allow the optimization of the presurgical mapping of lesion with adequate free margins.• The advantage of medical infrared thermography is to be used like a control tool after excision surgery if all the affected tissues are removed.• This study was therefore conducted as an effort to fill this knowledge gap.• We suggest that medical infrared thermography assessment be better performed with more case surgery.

Theoretical modeling of time-dependent skin temperature and heat losses during whole-body cryotherapy: A pilot study

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.

Hygrothermal performance of various Typha–clay composite:

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.

Infrared thermography applied to the study of the thermal behavior of wheelchair cushion

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 injuries sometimes also result from the friction of the skin against another surface or from the slip of 2 skin layers one against the other, in opposed directions, and which they damage the flesh which are in lower part. With that is added the effects of humidity and temperature (Fisher et al. 1978; Stewart et al. 1980) which softened the patient and which reduce his resistance. The effects of pressure on ulcers are well-known and were the object of several studies in literature (Mohanty and Mahapatra 2014). In the present study we will be interested in the effects of the temperature and his impact on the skin softening which can increase the ulcers environment. We propose a methodology to characterize the thermal performances of cushion environment using the infrared thermography, inspired from (Ferrarin and Ludwig 2000). The aim of this paper was to develop and modelize the effect of temperature on the cushion environment of users. Such a modeling has never been developed in literature and represents the originality of our study. After the quantification of temperature studying distribution on cushion seat and using the infrared methodology, the temperature impact was estimated through a simple convector-radiative model.