Centre d'Études et de Recherche en Thermique, Environnement et Systèmes

samples in Xi'an, China as an example were also studied. Geographically, the ARGs were detected to vary by nearly 100-fold in their abundances, for example, from 0.07 (Bandung, Indonesia) to 5.6 (San Francisco, USA). The β-lactam resistance gene blaTEM was found to be most abundant, seconded by quinolone resistance gene qepA; and their corresponding relative abundances have increased by 178% and 26%, respectively, from 2004 to 2014 in Xi'an. Independent of cities, gene network analysis indicates that airborne ARGs were differentially contributed by bacterial taxa. Results here reveal that urban air is being polluted by ARGs, and different cities are challenged with varying health risks associated with airborne ARG exposure. This work highlights the threat of urban airborne transmission of ARGs and the need of redefining our current air quality standards in terms with public health.

1. The Japan Aerospace Exploration Agency's (JAXA) Advanced Land Observing Satellite (ALOS) L-band Phased Array Synthetic Aperture Radar (PALSAR), launched successfully in January 2006, will provide new data sets for coastal ecosystems mapping and change monitoring at local to global scales. 2. To evaluate L-band capability for mangrove applications, data acquired by the NASA airborne SAR (AIRSAR) and Japanese Earth Resources Satellite (JERS-1 SAR) over sites in Australia, French Guiana and Malaysia were used to demonstrate benefits for mapping extent and zones, retrieving biomass and structural attributes (e.g. height), and detecting change. 3. The research indicates that mapping is most effective where mangroves border non-forested areas and where differences in structure, as a function of species, growth stage and biomass distributions, occur between zones. 4. Using L-band SAR, biomass can be retrieved up to ∼100–140 Mg ha−1, although retrieval is complicated by a noticeable decrease in L-band backscattering coefficient within higher (∼>200 Mg ha−1) biomass stands, particularly those with extensive prop root systems. 5. Change detection through multi-temporal comparison of data proved useful for mapping deforestation/regeneration and mangrove dynamics associated with changing patterns of sedimentation. 6. The research highlights the likely benefits and limitations of using ALOS PALSAR data and supports JAXA's Kyoto & Carbon (K&C) Initiative in promoting the use of these data for regional mangrove assessment. Copyright © 2007 John Wiley & Sons, Ltd.

The interconnection of the wind generator (WG) and the diesel generator (DG) induces some interactions on the common coupling point. These interactions are studied in this paper with the aim of identifying the system limits in performance and proposing an alternative solution. Due to the fast fluctuations of the WG and the DG slow dynamics, ultracapacitors and batteries are used for improving the hybrid system performances and reducing the fuel consumption. The dc-bus voltage is controlled by the diesel engine while providing a smoothed current. To ensure optimized life cycle cost and performance, a lifetime-estimation-based method is proposed. In this method, a rainflow counting method is applied to size the storage devices by taking into account the actual conditions of the system operation. The experimental test bench is designed in a reduced scale. Some simulations and experimental results are presented and analyzed.

Abstract This article is dedicated to the study of the thermal parameters of composite materials. A nonlinear least‐squares criterion is used on experimental transfer functions to identify the thermal conductivity and the diffusivity of aluminum‐polymer composite materials. The density measurements were achieved to deduce the specific heat and thereafter they were compared to values given by differential scanning calorimetry measurement. The thermal parameters of the composite material polypropylene/aluminum were investigated for the two different types of aluminum filler sizes. The experimental data were compared with several theoretical thermal conductivity prediction models. It was found that both the Agari and Bruggeman models provide a good estimation for thermal conductivity. The experimental values of both thermal conductivity and diffusivity have shown a better heat transport for the composite filled with large particles. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 722–732, 2004

A periodic method is used to determine simultaneously both thermal conductivity and diffusivity of various polymer materials at room temperature. The sample is placed between two metallic plates and temperature modulation is applied on the front side of one of the metallic plates. The temperature at the front and rear sides of both plates is measured and the experimental transfer function is calculated. The theoretical thermal heat transfer function is calculated by the quadrupole method. Thermal conductivity and diffusivity are simultaneously identified from both real and imaginary parts of the experimental transfer function. The thermophysical parameters of several polymer samples (PTFE, PVDF and PA11) with different thicknesses (respectively, 5 mm, 2 mm and 300 µm) were studied and compared with values from the literature. The values identified for the thermal parameters are in good agreement with values from the literature for PTFE and PVDF samples; however, we show that the method reaches its limit for the thinner PA11 sample, owing to inadequacy of the thermal model.

In this paper, we show how to compute an over-approximation for the reachable set of uncertain nonlinear continuous dynamical systems by using guaranteed set integration. We introduce two ways to do so. The first one is a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">full interval</i> method which handles whole domains for set computation and relies on state-of-the-art validated numerical integration methods. The second one relies on <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">comparison theorems</i> for differential inequalities in order to bracket the uncertain dynamics between two dynamical systems where there is no uncertainty. Since the derived bracketing systems are piecewise <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ck</i> -differentiable functions, validated numerical integration methods cannot be used directly. Hence, our contribution resides in the use of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hybrid automata</i> to model the bounding systems. We give a rule for building these automata and we show how to run them and address mode switching in a guaranteed way in order to compute the over approximation for the reachable set. The computational cost of our method is also analyzed and shown to be smaller that the one of classical interval techniques. Sufficient conditions are given which ensure the epsiv-practical stability of the enclosures given by our <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hybrid bounding method</i> . Two examples are also given which show that the performance of our method is very promising.

Eleven day-old grass pea plants (Lathyrus sativus L.) were grown hydroponically for 96 h in the presence of 0.5 mM lead nitrate (Pb(NO(3))(2)). The survival rate was 100%. The mean lead content (measured by ICP-OES) in root tissues was 153 mg Pb g(-1) dry matter. Over three quarters of the lead was not labile. Compared with control plants, lead-exposed plants showed a six-fold, two-fold and three and a half-fold reduction in their root calcium, zinc and copper contents, respectively. Together, these results suggested that Lathyrus sativus L. was tolerant to a deficiency in essential nutrients and able to store large amounts of lead in its root tissues. Therefore, it could be used for the development of new rhizofiltration systems.

This study investigated the morphology, tensile properties, thermal conductivity, and thermal stability of short carbon fiber reinforced polypropylene (CF/PP) composites. CF/PP composites were prepared with varying amounts of short carbon fiber (9, 15, 20, 25, and 30 wt%) in PP matrix with and without maleic anhydride grafting PP as a coupling agent. Samples were prepared by extrusion blending followed by injection molding. Results showed that the addition of CFs significantly improved the tensile modulus and tensile strength of composites by 455% and 168%, respectively, at 30 wt% loading compared with pure PP. Thermogravimetric analysis results indicated that increasing the CF content improved the thermal stability of composites compared with PP. In addition, thermal conductivity increased with increasing CF weight fraction. The microstructural analysis results showed that maleic anhydride grafting PP improved the adhesion between carbon fibers and PP matrix. POLYM. COMPOS., 39:E664–E670, 2018. © 2016 Society of Plastics Engineers

Abstract Type I interferons (IFN) are being rediscovered as potent anti-tumoral agents. Activation of the STimulator of INterferon Genes (STING) by DMXAA (5,6-dimethylxanthenone-4-acetic acid) can induce strong production of IFNα/β and rejection of transplanted primary tumors. In the present study, we address whether targeting STING with DMXAA also leads to the regression of spontaneous MMTV-PyMT mammary tumors. We show that these tumors are refractory to DMXAA-induced regression. This is due to a blockade in the phosphorylation of IRF3 and the ensuing IFNα/β production. Mechanistically, we identify TGFβ, which is abundant in spontaneous tumors, as a key molecule limiting this IFN-induced tumor regression by DMXAA. Finally, blocking TGFβ restores the production of IFNα by activated MHCII + tumor-associated macrophages, and enables tumor regression induced by STING activation. On the basis of these findings, we propose that type I IFN-dependent cancer therapies could be greatly improved by combinations including the blockade of TGFβ.

Phase change materials (PCM) are attractive candidates for energy storage. They can store large quantities of energy in small volumes at nearly constant temperatures. Despite their advantage, their thermal conductivity is very low with a high-volume change during the melting and solidification process. One way to increase their poor thermal conductivity is to embed them into open cell metallic foams. In this paper, a numerical study is conducted on the effect of the heating and cooling conditions on phase change kinetics of paraffin embedded in a metal foam. Constant heating and sinusoidal heating are similarly investigated. For the constant heat flux, a step function ranging from +1800 W/m2 to −1800 W/m2 is considered, while for the variable heat flux, a sinusoidal function having a similar area as step function is considered at one wall of the container to provide heating and cooling of the PCM/Metal foam composite. A new mathematical model based on the Brinkmann-Forchheimer-extended Darcy equation and the local thermal non-equilibrium model (LTNE) is proposed by applying a two-energy equation. The paraffin phase change is modeled using the enthalpy-porosity method. The numerical results are validated by comparing them with the experimental data. The results showed that at the time of melting it has reduced with sinusoidal heating. The results also showed that the heat losses on the boundary have a greater effect in a sinusoidal heat flux case than in constant heat flux case and this effect is more important on the solidification than on the melting process of the paraffin.

The adobe is a widely used traditional material in popular constructions in rural areas of Peru and more generally in Andean countries. In order to increase comfort and energy efficiency of constructions, it is necessary to better know the thermal characteristics of the adobe, seen as a bio-composite material. Different adobes have been studied. Effective thermal conductivity and heat capacity were measured by means of a hot parallel-plate method. Density was estimated using a pycnometer and measuring physical dimensions and mass of each sample, which allowed the calculation of thermal effusivity and diffusivity. Some numerical simulation results displayed good agreement with experimental outcomes. The work presented here has implications for future studies of this traditional building material and might potentially help solving the problem of sustainable housing.

The storage of thermal energy in phase change materials (PCMs) has found wide applications that enable energy conservation and management. Paraffin is a major PCM with its low cost, wide availability, and relatively high latent heat, yet its low thermal conductivity may become a drawback in high-power applications. In this study, composites of paraffin were prepared with multiwalled carbon nanotubes and activated carbon by a dispersion technique to overcome these drawbacks. Thermal, chemical, and physical influences of incorporating carbon additives with varying structures in paraffin composites on thermal storage capacity were determined. Results indicated that the thermal conductivities of paraffin-activated carbon composites (PACC) and paraffin multiwalled carbon nanotube composites (PCNC) were improved by a factor of 39.1 and 34.1%, respectively, compared with the conductivity of pure paraffin. As a bonus, the thermal energy storage capacities of PCNCs were enhanced by 9.6%, whereas this remained unchanged for PACCs. Copyright © 2015 John Wiley & Sons, Ltd.

Abstract In this paper, a critical issue related to power management control in autonomous hybrid systems is presented. Specifically, challenges in optimizing the performance of energy sources and backup systems are proposed, especially under conditions of heavy loads or low renewable energy output. The problem lies in the need for an efficient control mechanism that can enhance power availability while protecting and extending the lifespan of the various power sources in the system. Furthermore, it is necessary to adapt the system's operations to variations in climatic conditions for sustained effectiveness. To address the identified problem. It is proposed the use of an intelligent power management control (IPMC) system employing fuzzy logic control (FLC). The IPMC is designed to optimize the performance of energy sources and backup systems. It aims to predict and adjust the system's operating processes based on variations in climatic conditions, providing a dynamic and adaptive control strategy. The integration of FLC is specifically emphasized for its effectiveness in balancing multiple power sources and ensuring a steady and secure operation of the system. The proposed IPMC with FLC offers several advantages over existing strategies. Firstly, it showcases enhanced power availability, particularly under challenging conditions such as heavy loads or low renewable energy output. Secondly, the system protects and extends the lifespan of the power sources, contributing to long-term sustainability. The dynamic adaptation to climatic variations adds a layer of resilience to the system, making it well-suited for diverse geographical and climatic conditions. The use of realistic data and simulations in MATLAB/Simulink, along with real-time findings from the RT-LAB simulator, indicates the reliability and practical applicability of the proposed IPMC strategy. Efficient load supply and preserved batteries further underscore the benefits of the fuzzy logic-based control strategy in achieving a well-balanced and secure system operation.

Abstract Individuals with viral infection could possibly emit an infectious aerosol. The distinction between exhaled breaths of infected and healthy individuals should facilitate an understanding of the airborne transmission of infections. In this context, the present study is aimed at distinguishing healthy individuals from symptomatic ones by the study of their exhaled breath. A setup composed of a modified hood connected to an electrical low pressure impactor, which allows for the study of a wide range of particle sizes (from 7 nm to 10 μm), has been developed in order to collect exhaled breaths. This setup has been used with seventy eight volunteers. The results obtained using Principal Component Analysis (PCA) showed that exhaled breaths of individuals without symptoms have statistical similarities and are different from those of individuals with symptoms. This separation was made by the greater proportional emission by individuals with symptoms of particles collected on stages 3 ( D 50 = 0.09 μm), 6 ( D 50 = 0.38 μm), 8 ( D 50 = 0.95 μm), 10 ( D 50 = 2.40 μm), and 12 ( D 50 = 4.02 μm) of the impactor. There was not a specific size distribution obtained for the individuals with symptoms. As a consequence, further research on the exhaled breath should be undertaken with symptomatic volunteers and would require the analysis of this wide range of particle sizes.

Abstract The concentration dependence of specific heat, electrical and thermal conductivities of nanocomposites based on high‐density polyethylene (HDPE) filled with silver nanoparticles have been investigated. The composites filled with high filler content show high electrical and thermal conductivities. The dielectric relaxation spectroscopy was used to investigate the electrical properties in the studied systems. The scaling law of electrical percolation was used for an exact estimation of the percolation threshold ( P c ). A low electrical percolation threshold was found in the investigated composites. The rule of mixture was sufficient for the prediction of the specific heat dependence of HDPE–Ag nanocomposites as a function of the weight filler content. The basic models of the thermal conductivity have a tendency to underestimate the measured values for the low and high filler concentrations. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Infrared emissivity is a necessary parameter for computing models to predict road surface status and pavement temperature irrespective of the weather situation. In this work a new experimental device based on the indirect method was developed for the measurement of surface emissivities. The surface is exposed to modulated isotropic infrared radiation. The intensity reflected by the surface of the sample in a given direction is measured by a detector operating in the spectral range 1–40 µm. This large spectral range allows measurement of the total hemispheric emissivity defined in this case as emissivity. The effect of the temperature modulation frequency, surface composition and surface roughness on the emissivity measurements was investigated. The results show good ability of the device for the determination of emissivities at room temperature.

In recent years, considerable attention has been given to the development and utilization of natural fibres. This study examines the thermal properties of maize thermomechanical fibre reinforced high density polyethylene composites with competitive mechanical properties. The composites were produced by six different steps, namely: drying, cutting, mixing, compounding, pelletizing and injection moulding. Composite samples with fibre contents in the range 10–40 wt% were chosen to observe their effect on thermal and mechanical properties as the fibre content was increased. Measurements of thermophysical properties were obtained using periodic temperature ramp method. The material characterization was performed on a temperature range that extends from −20℃ to 120℃. It was found that the thermal conductivity and diffusivity of the composites decrease with fibre loading. The results showed that when the temperature is increased, a significant increase of both thermal effusivity and the factor [Formula: see text] was observed. A high-quality dispersion and adhesion of maize fibre in the high density polyethylene matrix was indicated by scanning electron microscopy. Good mechanical performance of the obtained composites was established considering the stress transfer at fibre–matrix interface.

Abstract. An ensemble Kalman filter (EnKF) has been coupled to the CHIMERE chemical transport model in order to assimilate ozone ground-based measurements on a regional scale. The number of ensembles is reduced to 20, which allows for future operational use of the system for air quality analysis and forecast. Observation sites of the European ozone monitoring network have been classified using criteria on ozone temporal variability, based on previous work by Flemming et al. (2005). This leads to the choice of specific subsets of suburban, rural and remote sites for data assimilation and for evaluation of the reference run and the assimilation system. For a 10-day experiment during an ozone pollution event over Western Europe, data assimilation allows for a significant improvement in ozone fields: the RMSE is reduced by about a third with respect to the reference run, and the hourly correlation coefficient is increased from 0.75 to 0.87. Several sensitivity tests focus on an a posteriori diagnostic estimation of errors associated with the background estimate and with the spatial representativeness of observations. A strong diurnal cycle of both these errors with an amplitude up to a factor of 2 is made evident. Therefore, the hourly ozone background error and the observation error variances are corrected online in separate assimilation experiments. These adjusted background and observational error variances provide a better uncertainty estimate, as verified by using statistics based on the reduced centered random variable. Over the studied 10-day period the overall EnKF performance over evaluation stations is found relatively unaffected by different formulations of observation and simulation errors, probably due to the large density of observation sites. From these sensitivity tests, an optimal configuration was chosen for an assimilation experiment extended over a three-month summer period. It shows a similarly good performance as the 10-day experiment.

In the last two decades, multidisciplinary research teams worked on developing a comprehensive understanding of the transmission mechanisms of airborne diseases. This article reviews the experimental studies on the characterization of the exhaled airflow and the droplets, comparing the measured parameters, the advantages, and the limitations of each technique. To characterize the airflow field, the global flow-field techniques-high-speed photography, schlieren photography, and PIV-are applied to visualize the shape and propagation of the exhaled airflow and its interaction with the ambient air, while the pointwise measurements provide quantitative measurements of the velocity, flow rate, humidity and temperature at a single point in the flow field. For the exhaled droplets, intrusive techniques are used to characterize the size distribution and concentration of the droplets' dry residues while non-intrusive techniques can measure the droplet size and velocity at different locations in the flow field. The evolution of droplets' size and velocity away from the source has not yet been thoroughly experimentally investigated. Besides, there is a lack of information about the temperature and humidity fields composed by the interaction of the exhaled airflow and the ambient air.

The most frequent autoimmune adult inflammatory myopathies are dermatomyositis, polymyositis, inclusion body myositis, and sarcoid myopathy. Interleukin-1 (IL-1) is a pleiotropic molecule, implicated in the inflammatory process, but also in tissue protection and remodelling. We evaluated the immunocytochemical expression of [L,-1alpha and beta in frozen muscle biopsy specimens from patients with dermatomyositis (15 cases), polymyositis (five cases), inclusion body myositis (five cases) and sarcoid myopathy (five cases). Positive immunoreactivities, were observed in both inflammatory cells and muscle fibres. Specificity of the immunostaining was assessed by Western blot experiments. IL-1 positive inflammatory cells were rare in polymyositis and inclusion body myositis, moderately abundant in dermatomyositis, and prominent in sarcoid myopathy granulomas. In sarcoid myopathy, 24.6 +/- 4.1% inflammatory cells were IL-1alpha-positive and 45.2 +/- 2.6% were IL-1beta-positive. IL-1 positive muscle fibres were mainly observed in dermatomyositis, usually remote from inflammatory infiltrates. Positive immunostaining for IL-1 was observed in fibres showing ischaemic punched-out vacuoles, that correspond to areas of myosinolysis, in atrophic perifascicular fibres, and in fibres located within healing microinfarcts. All NCAM-positive regenerating fibres were IL-1 positive. We conclude that: (i) IL-1 is expressed in granulomas of sarcoid myopathy, which is in keeping with the role ascribed to IL-1 in the formation of granulomas: (ii) IL-1 is expressed by muscle fibres undergoing ischaemic damage: and (iii) IL-1 expression by muscle fibres is associated with myofibrillar protein breakdown and regeneration.