HAL Université de Toulouse, et Toulouse INP
Not a member yet
159308 research outputs found
Sort by
A review of operational factors affecting photovoltaic system performance
No full textInternational audienceThe reduction in manufacturing costs of photovoltaic (PV) systems has driven significant growth in the PV industry. This expansion has shifted the current challenge from constructing new PV systems to maximizing the performance and longevity of installed PV modules. PV performance is influenced by two major categories of factors: environmental and operational. While environmental factors, such as dust and temperature, have been extensively studied, operational factors -critical for optimizing system efficiency -have not received the same level of attention. This study analyzes 102 articles focusing on operational factors such as PV technology, tilt and orientation angles, surface properties, height, and component aging, while also examining their interaction with environmental factors, particularly dust. In addition, the study compiles a set of standardized metrics aimed at quantifying efficiency losses and enabling consistent comparisons across studies. Finally, this review outlines a roadmap identifying key research gaps and provides recommendations for improving PV system performance. This roadmap offers valuable insights for researchers, engineers, and policymakers to better understand and address the operational factors that influence the efficiency and lifespan of PV systems
L'occitan: Quelques contrastes pertinents entre l'occitan et le français
No full textPrésentation succincte de l'occitan (langue, phonologie, grammaire) dans une optique contrastive occitan/françai
Fast and accurate relatedness estimation from high-throughput sequencing data in the presence of inbreeding
No full textInternational audienceBackground: The estimation of relatedness between pairs of possibly inbred individuals from high-throughput sequencing (HTS) data has previously not been possible for samples where we cannot obtain reliable genotype calls, as in the case of low-coverage data.Results: We introduce ngsRelateV2, a major revision of ngsRelateV1, a program that originally allowed for estimation of relatedness from HTS data among non-inbred individuals only. The new revised version takes into account the possibility of individuals being inbred by estimating the 9 condensed Jacquard coefficients along with various other relatedness statistics. The program is threaded and scales linearly with the number of cores allocated to the process.Conclusion: The program is available as an open source C/C++ program under the GPL license and hosted at https://github.com/ANGSD/ngsRelate. To facilitate easy analysis, the program is able to work directly on the most commonly used container formats for raw sequence (BAM/CRAM) and summary data (VCF/BCF)
Magnetic Polymersome Deformation by a Static Magnetic Field
No full textInternational audienceIncorporation of superparamagnetic iron oxide nanoparticles (SPION) in polymer vesicles has been mostly studied as means to cancer cell death induction via drug encapsulation and delivery at the tumor site [1]. Nonspherical polymeric nanostructures prevail over spherical ones in terms of circulation time, cell up-take amount and kinetics [2]. Our study aims at preparing such anisotropic magnetic polymersomes and use them as mechanical actuators to destroy cells by mechanical torques under rotating magnetic fields.Such “nano-blenders” were prepared by co-assembly of hydrophobically SPIONs with amphiphilic block copolymers (BCPs) constituting the membranes. Two topologies of BCPs were designed: triblock BCPs with either linear or comb-like topology. While the hydrophilic block was always poly(ethylene oxide) (PEO), the hydrophobic part was composed of two polymers chosen for their soft rubbery state (i.e. low Tg), polyisoprene (PI) which double-bonds were epoxidized and further cross-linked, and poly(trimethylene carbonate) (PTMC), both ones being reported to self-assemble into polymersomes when designed as diblock copolymer with PEO. Then we studied the deformation of those vesicles in a static magnetic field and the shift of their morphology from spherical to (slightly) elongated. During this elongation process, the hydrophobic membranes were crosslinked by irradiation with either UV or Gamma rays. For this aim, a fraction of double bonds in the PI block was epoxidized followed by cationic ring opening via a cationic photo-initiator. These vesicles were incorporated into cancer cells, and owing to their anisotropy used to exert mechanical torques when rotating magnetic field was applied, forcing the vesicles to rotate, thereby damaging internal cell compartments, and leading to apoptosis. References (max. 5): 1. H. Oliveira, E. Pérez-Andrés, J. Thevenot, O. Sandre, E. Berra, and S. Lecommandoux, “Magnetic field triggered drug release from polymersomes for cancer therapeutics,” J. Control. Release 169, 165–170 (2013).2. E. Scarpa, C De Pace, AS Joseph, SC de Souza, A Poma E Liatsi-Douvitsa, C Contini, V De Matteis, J Samitier Martí,G. Battaglia, L. Rizzello, “Tuning cell behavior with nanoparticle shape”, PLoS One 15, e0240197E (2020).Acknowledgement:This work received funding from the French National Research Agency, project “Magnetic VEsicle Rotation Induced Cell Killing” (MAVERICK, ANR-19-CE09-0024) and from the French Ministry of Foreign Affairs (PHC Pavlic Savić 2023 “Preservation of magnetic polymersomes’ anisotropic morphology via gamma irradiation induced crosslinking”
The ParB-CTP Cycle Activates Phase Separation in Bacterial DNA Segregation
No full textCell function relies on liquid-like organelles formed through phase transitions, yet the mechanisms ensuring their specificity and rapid assembly remain poorly understood. In bacterial chromosome segregation via the ParABS system, hundreds of ParB proteins are recruited around the centromere-like parS sequence forming the partition complex. Recent studies have shown that ParB binds CTP and undergoes cycles of binding and unbinding near parS, however, this accounts for the recruitment of only a small fraction of ParB molecules, leaving its role unclear. Separately, a lattice gas model with fixed interaction energy has been proposed to describe ParB phase separation, but it fails to explain key experimental observations, including the absence of droplets in ParB variants. We reconcile these two perspectives by proposing that the ParB-CTP cycle acts as a molecular switch that enhances ParB-ParB interactions, triggering phase transition from vapor to liquid-like condensates. Our hypothesis is supported by numerical simulations of droplet formation and experiments showing that ParB variants disrupting the CTP cycle fail to undergo phase separation. These findings establish a mechanistic framework for ParB-CTP-mediated phase transitions and may have broader implications for understanding the spatial control of intracellular condensate formation.</div
Combining Geometric and Photometric 3D Reconstruction Techniques for Cultural Heritage
No full textInternational audienceThere are mainly two families of photographic 3D reconstruction techniques.Photogrammetry techniques work according to the principle of triangulation, from the matching of dierent views, while photometric techniques link the appearance of a 3D point to the orientation of its normal, relative to that of the incident light. While photogrammetry allows to nd the global shape of a 3D scene, if it is suciently textured, photometric techniques highlight the details of the relief, as long as the model linking the lighting to the shape and reectance of the scene is suciently realistic. In this work, we compare these dierent approaches with some others in the context of reconstructing archaeological features. After discussing their advantages and disadvantages, we describe a promising new method combining both families in a multi-view, multi-lighting context.</p
Mie-scattering imaging and μ PIV in porous media burners with TPMS-based topologies
No full textInternational audienceIn this work, Mie-scattering imaging, CH ⋆ chemiluminescence and µPIV are applied in various optically accessible Porous Media Burners (PMBs). The present PMBs are generated using Triply Periodic Minimal Surfaces (TPMS) and produced via Additive Manufacturing (AM). These topologies feature optical pathways that are both orthogonal and coincident, so that one can be used for illumination and the other for imaging. This enables the application of laser diagnostics in fully 3D structures whilst avoiding altering the geometry of the porous medium. These techniques are applied in homogeneous porous burners where the position of the flame is determined by the operating conditions. First, Mie-scattering imaging is combined with CH ⋆ chemiluminescence to analyze the influence of the flame position on the preheating distance of the reactants. For that, the flow is seeded with micrometric oil droplets that evaporate at approximately 500 K. The light scattered by these particles delineates an evaporation front in the Miescattering images and this can be compared to the actual location of the reaction region which is deduced from chemiluminescence images. Then, Mie-scattering imaging and µPIV are used to obtain the flame shape and the velocity field in the unburned gas region for inlet-anchored flames. The influence of the hydrogen content, the pore-size and the burner topology is analyzed. The topology is found to have a major impact on the interstitial flow and flame stabilization. A new topological parameter, namely the linear porosity, is proposed to quantify the influence of local hydrodynamic effects on flame stabilization
Optimization of surface texturing parameters in additively manufactured continuous fiber composites using abrasive waterjet technique for composite repair applications
No full textInternational audienc
Resource economics of tree communities control soil food web multifunctionality in European forests
No full textPlants affect terrestrial ecosystem functioning by performing the primary production that energetically sustains heterotrophic organisms, and by shaping the microenvironment. However, the influence of plant diversity and community composition on ecosystem functioning through their effects on energy flow into food webs has been little studied, especially for soil food webs that channel most of the plant-derived energy. Applying a food web energetics approach, we show that the resource economics of dominant tree species control soil food web multifunctionality across European forests. Specifically, tree communities dominated by resource acquisitive species promoted faster rates of multiple soil trophic functions simultaneously than did those dominated by resource conservative species. This was primarily driven by their production of plant litter with higher nutritional quality and their warmer forest microclimate, leading to a higher metabolic activity of soil organisms. Tree species mixing had rather weak and negative effects on soil food web multifunctionality, mostly due to a shift in the resource-based energy channeling from living plant fine roots to litter and a cooling effect on the forest microclimate. Tree diversity effects were largely outweighed by community compositional effects, which were of similar magnitude to the effects of biogeographic differences among locations. Our findings emphasize the importance of plant functional traits related to resource economics as drivers of plant community effects on soil food web functioning5,9 and highlight the consequences that climate-driven shifts in tree community composition could have for forest soil functioning
Systematic biases from the exclusion of higher harmonics in parameter estimation on LISA binaries
No full textInternational audienceThe remarkable sensitivity achieved by the planned Laser Interferometer Space Antenna (LISA) will allow us to observe gravitational-wave signals from the mergers of massive black hole binaries (MBHBs) with signal-to-noise ratio (SNR) in the hundreds, or even thousands. At such high SNR, our ability to precisely infer the parameters of an MBHB from the detected signal will be limited by the accuracy of the waveform templates we use. In this paper, we explore the systematic biases that arise in parameter estimation if we use waveform templates that do not model radiation in higher-order multipoles. This is an important consideration for the large fraction of high-mass events expected to be observed with LISA. We examine how the biases change for MBHB events with different total masses, mass ratios, and inclination angles. We find that systematic biases due to insufficient mode content are severe for events with total redshifted mass . We then compare several methods of predicting such systematic biases without performing a full Bayesian parameter estimation. In particular, we show that through direct likelihood optimization it is possible to predict systematic biases with remarkable computational efficiency and accuracy. Finally, we devise a method to construct approximate waveforms including angular multipoles with to better understand how many additional modes (beyond the ones available in current approximants) might be required to perform unbiased parameter estimation on the MBHB signals detected by LISA