HAL Université de Toulouse, et Toulouse INP
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Mechanoluminescence driven by oxidation reactions in epoxy resins
No full textInternational audienceThe luminescence of two imidazole or anhydride cured epoxy resins has been investigated under the combined effect of mechanical stress and temperature using a special experimental setup developed for this purpose. Rupture and cyclic mechanical tests have been conducted in air and in nitrogen between room temperature and 110 °C. Luminescence was acquired through both temporal and spectral acquisitions. Light emission is observed only in air, and fits a Zhurkov model of bond scission. Spectral measurements show that adding a mechanical component to a thermal stress does not excite new molecular groups, indicating that degradation mechanisms under thermal stress or both thermal and mechanical stresses could be similar. A simple two-step model is proposed to describe luminescence as a combination of bond scission and light decay
Euclid preparation LXX. Forecasting detection limits for intracluster light in the Euclid Wide Survey
No full textInternational audienceThe intracluster light (ICL) permeating galaxy clusters is a tracer of the cluster's assembly history, and potentially a tracer of their dark matter structure. In this work we explore the capability of the Euclid Wide Survey to detect ICL using H-band mock images. We simulate clusters across a range of redshifts (0.3-1.8) and halo masses (- M), using an observationally motivated model of the ICL. We identify a 50-200 kpc circular annulus around the brightest cluster galaxy (BCG) in which the signal-to-noise ratio (S/N) of the ICL is maximised and use the S/N within this aperture as our figure of merit for ICL detection. We compare three state-of-the-art methods for ICL detection, and find that a method that performs simple aperture photometry after high-surface brightness source masking is able to detect ICL with minimal bias for clusters more massive than M. The S/N of the ICL detection is primarily limited by the redshift of the cluster, driven by cosmological dimming, rather than the mass of the cluster. Assuming the ICL in each cluster contains 15% of the stellar light, we forecast that Euclid will be able to measure the presence of ICL in up to clusters of >10^{14.2} M between and 1.5 with a S/N>3. Half of these clusters will reside below and the majority of those below will be detected with a S/N >20. A few thousand clusters at M. Euclid will detect the ICL at more than 500 kpc distance from the BCG, up to , in several hundred of these massive clusters over its large survey volume
A coiled‐coil domain triggers oligomerization of MmpL10 , the mycobacterial transporter of trehalose polyphleate precursor
No full textInternational audienceThe mycobacterial outer membrane is composed of unusual lipids and glycolipids. Some of these lipids are exported to the cell envelope by resistance‐nodulation‐division (RND) transporters called mycobacterial membrane protein large (MmpL). While the oligomeric state of most RND transporters is well established, MmpL assembly remains unclear. Here, we investigated MmpL10, the trehalose polyphleate transporter. Biochemical data suggest that MmpL10 forms a homotrimer and that its oligomerization is driven by a coiled‐coil domain. Structural modeling and electron microscopy data reveal the presence of a tubular extension that spans the mycobacterial cell wall and reaches the mycomembrane. As most MmpL proteins possess this extension, oligomerization may be a common feature of this family of transporters, possibly involved in the transport of the MmpL cargo
La science de la durabilité appliquée à la médecine traditionnelle en Polynésie française : définition et présentation du projet SustainMedPol
No full textInternational audienceThe sustainability science is a new discipline, emerging as a result of the environmental, social, and economic challenges in the contemporary society. This interdisciplinary approach aims to provide answers to the 169 targets of the Sustainable Development Goals (SDGs). Preserving the knowledge of indigenous peoples is one of these SDGs. Especially, traditional medicine offering culturally acceptable, available, and cheap care, can be a basis for the development of sustainable health solutions. However, traditional medicine has ecological, sociocultural, scientific and regulatory challenges that sustainability science should answer to ensure its long-term survival. In French Polynesia, traditional medicine is the most practiced primary medicine, within more than 300 medicinal plants used to treat several illnesses. Nevertheless, since the 19th century, its practice had encountered many obstacles. Thus, the project funded by the French National Research Agency, “SustainMedPol”, lasting three years, aims to preserve, support, and valorise the traditional medical knowledge from French Polynesia by the proposition of solution implementing sustainable actions
Experimental Determination of a Spoke-Type Axial-Flux Permanent Magnet Motor’s Lumped Parameters
No full textInternational audienceThis study focuses on the experimental determination of the lumped parameters of a Spoke-Type Axial-Flux Permanent Magnet (STAFPM) motor. This type of motor offers high specific torque and is well-suited for transportation applications. The studied STAFPM motor uses Ferrite magnets, which are more environmentally friendly and economical than rare earth magnets. The identification of the lumped electromechanical model parameters is carried out using static torque measurements on a dedicated test bench. The torque measurements are performed in two stages: with and without magnets mounted in the rotor. The no-load flux is determined separately by no-load tests. Together, these tests identify the key parameters of the lumped parameter model, such as self- and mutual inductances, cogging torque, and no-load flux. These parameters are then used to complement the DQ model, commonly used in electric motor analysis. While the DQ model predicts average torque well, it cannot reproduce torque ripples. The lumped parameter model, validated by three-phase DC testing, provides an accurate representation of the motor’s behavior, including torque ripples. This study also applies Maximum Torque Per Ampere (MTPA) control strategies and offers a practical alternative to 3D Finite Element Analysis (FEA), thus aiding the design of STAFPM motors
Quantitative Study of a Full-scale Pedaling Mannequin for Wind Tunnel Testing
No full textHuman subjects introduce variability in cycling wind tunnel testing due to slight inconsistencies in position and fatigue. To address these limitations, this study introduces a dynamic, full-scale pedaling mannequin, capable of generating repeatable and controlled pedaling movements.The study focuses on three main objectives: (1) validating the mannequin's kinematics by comparing its pedaling motion to an idealized mechanical model, (2) quantifying the dynamic forces generated by the mannequin during operation and assessing their impact on measurement stability, and (3) evaluating the variability of aerodynamic measurements across different pedaling cadences and wind speeds. Experiments were conducted in a low-turbulence wind tunnel, with kinematic analysis performed using computer vision and force measurements recorded at multiple cadences and wind speeds.Results demonstrate that the mannequin produces highly repeatable pedaling motions with a minimal and maximal standard deviation of 0.24 % and 0.88 % across all tested conditions. The smallest detectable meaningful power change in optimal conditions was 1.61 W at 50 km/h and at a pedaling frequency of 67 rotations per minute. Pedaling-induced forces were shown to influence the aerodynamic drag measurements, highlighting the importance of distinguishing dynamic and aerodynamic components of the force signal. These findings establish the mannequin as a reliable tool for controlled aerodynamic analysis, with applications in both scientific research and performance optimization in competitive cycling
Suivi de l'excrétion des coccidies dans différents systèmes d'élevage intérieurs ou extérieurs par coproscopie et développement d'une technique de biologie moléculaire
No full textInternational audienceCoccidiosis is an obstacle to outdoor rabbit farming systems because it can lead to digestive disorders(diarrhoea), growth delay, and mortality. It is therefore crucial to control this disease. Monitoring the excretionof oocysts is usually carried out by coproscopy, counting the number of oocysts in the faeces and identifying thespecies under the microscope. This method can only process a limited number of samples per day. With a viewto phenotyping oocyst excretion in a large number of rabbits for future studies of genetic resistance tococcidiosis, we have developed a molecular biology tool for identifying the nine species of digestive coccidia.For this study, we had the opportunity to monitor coccidia excretion in young rabbits from the same herd,weaned at 35 days of age and kept in different contemporary conditions: 120 rabbits in 40 multi-purpose cages,120 rabbits in a 500 m2 outdoor parks, 32 rabbits in 4 groups of 8 rabbits in 50 m2 outdoor parks. Totalmorbidity and mortality were recorded. Coproscopies were carried out to get the quantities of oocysts andpresent species. The same samples were then analyzed by PCR. DNA extraction was developed with a kit usingceramic beads to mechanically lyse the oocysts, and magnetic beads to bind the DNA. This method is compatiblewith the use of an automatic extraction machine, and enables 32 faecal samples to be processed in parallel. PCRprimers specific to the nine species of rabbit digestive coccidia have been validated (E. coecicola, E. exigua, E.flavescens, E. intestinalis, E. irresidua, E. magna, E. media, E. perforans, E. piriformis). Coccidia excretion washigher in animals kept outdoors, with a greater diversity of species (identified microscopically or by PCR). Onaverage, excretion during the rearing period ranged from 0 OPG (oocysts per gram of faeces) to 517 0PG inbuildings, and from 0 to 34450 OPG in outdoor rearing. Only two species were observed in buildings (E. mediaand E. perforans). Outdoors, E. flavescens, E. exigua, E. piriformis, E.intestinalis and E. coecicola werealsodetected.The PCR method for detecting coccidia is promising, but the consistency between directobservationsand PCR results needs to beimproved.La coccidiose est un frein à l'élevage de lapins à l'extérieur car elle peut entraîner des troubles digestifs (diarrhées), des retards de croissance et de la mortalité. Il est donc crucial de maîtriser cette maladie. Le suivi de l'excrétion des ookystes s'effectue habituellement par coproscopie, avec un comptage du nombre d'ookystes dans les fèces et une identification des espèces présentes au microscope. Cette méthode ne permet de traiter qu'un nombre limité d'échantillons par jour. Dans l'optique de pouvoir phénotyper l'excrétion des ookystes chez un grand nombre de lapins pour de futures études de résistance génétique à la coccidiose, nous avons développé un outil de biologie moléculaire d'identification des neuf espèces de coccidies digestives. Pour cette étude, nous avons eu l'opportunité de suivre l'excrétion des coccidies de jeunes lapins issus du même troupeau, sevrés à 35 jours et conduits selon des modalités différentes et contemporaines : 120 lapins en 40 cages polyvalentes ; 120 lapins en parc extérieur de 500 m 2 ; 32 lapins en 4 groupes de 8 lapins en parcs extérieurs de 50 m 2 . La morbidité totale et la mortalité ont été enregistrées. Des coproscopies ont été réalisées pour avoir une première approche des quantités d'ookystes et des espèces présentes. Puis les mêmes échantillons ont été analysés en PCR. L'extraction de l'ADN a été développé avec un kit utilisant des billes de céramique lyser mécaniquement les ookystes, et des billes magnétiques pour fixer l'ADN. Cette méthode est compatible avec l'utilisation d'un automate d'extraction et permet de traiter 32échantillons de fèces en parallèle. Des amorces PCR spécifiques des neuf espèces de coccidies digestives du lapin ont été validées</div
Regard juridique sur les dix ans de la loi relative à l'économie sociale et solidaire.
No full textInternational audienceRegard juridique sur les dix ans de la loi relative à l'économie sociale et solidaire
Degradation of Micropollutants in Wastewater Using Photocatalytic TiO2@Ag-NPs Coatings Under Visible Irradiation
No full textInternational audienceThe contamination of aquatic ecosystems by the micropollutants in wastewater discharges is currently a critical issue. Therefore, the development of novel treatment processes and materials is essential to ensure the availability of safe water. The present study aims to develop a photocatalytic material composed of silver nanoparticles (Ag-NPs)-doped TiO2 supported on a Pyrex® plate (TiO2@Ag-NPs) exhibiting catalytic activity under visible irradiation (λ > 400 nm). The effects of Ag-NPs doping on the TiO2 matrix, the resistance of the coating at the catalyst/substrate interface, and the photocatalytic degradation efficiency of the photocatalyst for a micropollutant (diuron) of the pesticide family were studied. The photocatalyst was characterised using X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometry, and scratch tests. The solution concentrations were monitored using high-performance liquid chromatography and total organic carbon analyses. A 32% diuron removal was achieved using photocatalytic TiO2@Ag-NPs under visible irradiation, whereas undoped TiO2 showed no activity. Furthermore, the effects of the nanoparticle growth mode on the photocatalytic activity of TiO2@Ag-NPs were explored. The presence of a TiO2 sublayer ensured the adhesion of the coating and promoted the dispersion of nanoparticles within the matrix. It ensured chemical continuity (TiO2@Ag-NPs/Pyrex®), reduced the bandgap, and decreased electron–hole pair recombination
Thoracic Ultrasonography Findings and Their Association With Respiratory Pathogens in 221 Young Beef Cattle at Fattening Farms: A Cross‐Sectional Study
No full textInternational audienceABSTRACT Background Thoracic ultrasonography (TUS) could improve antibiotic treatment selection in cattle with respiratory diseases. Hypothesis/Objectives Evaluate the association between respiratory pathogens and consolidations on TUS in feedlot cattle, at both individual and group levels. Animals A total of 221 bulls, aged 8.8 months and weighing 322.5 ± 160 kg, from nine farms. Methods Cross‐sectional study including all data from clinical examinations and TUS collected weekly during the first month on feed. Pathogens were assessed by seroconversion (all animals) and qPCR on nasal swabs (sick animals). At the individual level, the association between pathogen detection and TUS consolidation was investigated using univariate logistic regression, and the ability of consolidation size to differentiate bacterial from non‐bacterial pneumonia was assessed using receiver operating characteristic curves. Principal component analysis identified clusters at the group level based on pathogen detection and TUS results. Results At the individual level, bulls infected with multiple pathogens (odds ratio [OR], 8.1; 95% confidence interval [CI], 2.21–29.8) or a single virus (OR, 5.49; 95% CI, 1.42–21.3) were more likely to have consolidations than those not infected. A total consolidation size > 14 cm 2 in the scanned thoracic region differentiated bacterial from non‐bacterial pneumonia with a sensitivity of 47.8% (95% CI, 36.4–83.3) and specificity of 94.1% (95% CI, 60.0–100.0). These results were consistent at the group level; clustering based on bacterial versus non‐bacterial etiology correlated with the number and size of consolidations. Conclusions and Clinical Importance Consolidation size could help differentiate bacterial from non‐bacterial pneumonia, guiding treatment at both individual and group levels