HAL Portal UPPA (University of Pau and the Pays de l'Adour)
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La protection des intérêts de l’État membre de l'Union européenne peut-elle être “abusive” ? Réflexions à partir de l'exercice du droit de veto par la Hongrie
No full textInternational audienc
Two stochastic versions of the Arps curve decline
No full textInternational audienceBased on the Arps equation, we propose two stochastic models for curve decline useful in oil engineering context. Theoretical properties and simulations of these models are provided. The first passage time distribution of these stochastic models to a constant level is then studied. In conclusion, we discuss about statistical inference of the parameters from the observations of the oil production cumulative rate.</div
Curcumin-modified gelatin nanocomplexes as novel food foaming Agents: Impact on foamability and interfacial properties
No full textInternational audienceAlthough polyphenol modification can enhance the foaming properties of hydrophilic gelatin, the mechanisms by which polyphenols affect gelatin interfacial and foaming behavior are not well understood. In this study, hydrophobic curcumin was used to modify gelatin (Type A), forming a nanocomplex designed as a novel foaming agent. In this study, we investigated the adsorption of curcumin/gelatin nanocomplexes at the air/water interface and the resulting foaming properties. Nanocomplexes were prepared at curcumin to gelatin mass ratios of 0, 0.05, 0.1, 0.15, and 0.2. Their bulk behavior was assessed based on particle size, zeta potential, complexation efficiency, and surface hydrophobicity. As the mass ratio of curcumin to gelatin increased from 0:1 to 0.2:1, the diameter of the nanocomplexes gradually increased from 32 nm to 279 nm, whereas their negative surface charge decreased from −3.4 mV to −1.3 mV. Additionally, surface hydrophobicity increased with curcumin addition, as indicated by the amount of bound bromophenol blue sodium, which rose from 11 μg to 30 μg. The interfacial properties were evaluated using dynamic surface pressure and dilatational rheology. The presence of curcumin increased the nanocomplex surface pressure, leading to enhanced foamability. The interfacial behavior was predominantly elastic; whereas, as the curcumin concentration increased, the elastic modulus did not improve significantly, resulting in no significant enhancement in foam stability. These findings suggest that curcumin/gelatin nanocomplexes are potential excellent foaming agents to be used in food, pharmaceutical, and other industries
Siffler en travaillant. Embarquer la recherche dans les projets Wikimédia et la science ouverte, le cas de l'occitan sifflé (siular d’Aas)
No full textNational audienceL'occitan sifflé est une modalité de l'occitan. Cette présentation s'attache à présenter ce corpus nativement en science ouverte et son positionnement par rapport aux enjeux du domaine de la musique
Bioactive composite scaffolds for antitumour drug delivery: a dual-functional approach through the combination of chitosan, calcium phosphate, and boric acid
No full textInternational audienceConventional bone tumour treatment often results in the disruption or collapse of the structural integrity of bone following tumour resection, while the accompanying application of chemotherapy frequently results in wide systemic damage due to toxicity. Such shortcomings in current bone tumour treatment options highlight the need for the development of multifunctional biomaterials that serve as systems for targeted drug delivery and biodegradable support, stimulating new bone formation. In this work, chitosan-calcium phosphate composite scaffolds were used as carriers for local delivery of antitumour drugs and therapeutic agents, while providing bioactive properties. The bioactivity of composite scaffolds was confirmed by an apatite-rich layer formation in an acellular in vitro test, and by osteogenic differentiation of human mesenchymal stem cells cultured for 21 days. The encapsulation of an antitumour drug, doxorubicin, was achieved through chemical crosslinking by genipin, while its release was characterised in a complete cell culture medium. The rapid release of doxorubicin affected the viability of human dermal fibroblasts (HDFa) and osteosarcoma cells (MG-63) when in contact with drug-loaded scaffolds. Following osteogenic properties, the modification of the composite scaffold with boric acid was also explored. The rapid release of boric acid from the composites was reported to be within the first three days of incubation, which stimulated a slight increase in the expression of vascular endothelial growth factor in HDFa cells. A biotolerability study was performed by chorioallantoic membrane (CAM) assay, indicating tissue infiltration into composite scaffolds with a lower concentration of boric acid. The rapid delivery of doxorubicin or boric acid from biodegradable and osteoconductive composite scaffolds shows the potential to address the clinical challenge of local tumour recurrence and poor bone regeneration following resection
Lumped and distributed activation energy modelling of biomass pyrolysis
No full textInternational audienceThe Distributed Activation Energy Model (DAEM) is applied to a semi-detailed degradation scheme, demonstrating its effectiveness in describing the complex kinetics of biomass pyrolysis. DAEM is a widely used tool for modelling the complex reaction rates and capturing the heterogeneous nature of lignocellulosic decomposition. First, the review provides the theoretical background to DAEM, highlighting its statistical basis and the assumptions underlying the distribution of activation energies. It then analyses advances in parameter estimation, numerical methods, and optimisation techniques that improve the reliability of DAEM fitting. Comparative studies with the constant activation energy model has been considered to clarify the strengths and limitations of DAEM. A significant part of the research paper summarises how DAEM has been applied to the main constituents of biomass: cellulose, hemicelluloses, and lignins. The model was validated using external data that was not used in the fitting procedure. Applications to real biomass has been discussed alongside recent efforts to extend the model to secondary reactions and gas formation. Finally, the study explores ways to extend DAEM towards more mechanistic degradation schemes by incorporating secondary reactions and pathways that lead to gas formation and levoglucosan degradation
Biomimetic CaCO3-chitosan hybrid pigments inspired by sea urchin spines biomineralization: a photostable colored additive for UV-protective self-supported chitosan films
No full textInternational audienceTo reduce the use of toxic and polluting synthetic pigments and dyes, which are still common in industry, marine biomimicry has inspired the development of functional hybrid materials to enhance the photoresistance of natural pigments. This is a key factor limiting their industrial use. Herein, we propose to develop a new type of photostable hybrid pigment, inspired by the biomineralization process of calcium carbonate (CaCO3), which traps natural organic dyes within sea urchin spines. Alizarin (polyhydroxyanthraquinone, AZ) was selected to mimic organic chromophores present in sea urchins, i.e. polyhydroxynaphthoquinone. The biomacromolecules chitosan (CS) and α-poly-l-lysine (PLL) were used to imitate the organic matter involved in CaCO3 biomineralization in sea urchins, thanks to their abundance of amine groups (−NH2). Using a straightforward coprecipitation method under gentle conditions, it was shown that AZ dye molecules became embedded in a CaCO3 shell, thereby shielding them from photodegradation. It has been demonstrated that chitosan effectively aids in the coprecipitation process by stabilizing the vaterite polymorph, while α-poly-l-lysine has little impact on CaCO3 formation. To extend the potential of these hybrid pigments for applications such as UV-protective films for food packaging, self-supporting CaCO3/chitosan (CaCO3/CS) composite films and tinted hybrid pigment/chitosan (CaCO3-AZ/CS) films were developed, leveraging the excellent film-forming properties of chitosan. Different quantities of CaCO3(−AZ) particles were incorporated into the formulations to tailor the films' mechanical and optical characteristics
Dynamic real-time optimisation of district heating networks with online time-series training and machine learning forecasts
No full textInternational audienc
Avoir pour métier la production des frontières. Les professionnels des lieux d’enfermement des étrangers
No full textInternational audienc
Droit comme un arbre - Episode 4 : Justice alimentaire : nourrir le monde ou nourrir le marché ?
No full textDans ce quatrième épisode, la journaliste Camille Maestracci interroge Fabrice Riem, professeur de droit à l'université de Pau et des Pays de l’Adour, et Magali Ramel, juriste en post-doctorat à l'université de Nantes, tous deux spécialistes des questions autour du droit à l'alimentation.On y parle des limites de l'aide alimentaires, des lois du marché qui ne prennent pas en compte le droit à l'alimentation et de la nécessité d'une approche par les droits.Pour aller plus loin : https://citizens-initiative.europa.eu/initiatives/details/2025/000002_fr"Droit comme un arbre" est un podcast du projet JUSCOOP - justice énergétique : l'énergie comme un "commun" financé par le programme de recherche PUCA ainsi que par l’Ademe et imaginé par Blanche Lormeteau, chargée de recherche au CNRS. Écrit et réalisé par Camille Maestracci