© Evelyn Hockstein/REUTERS
Après des années de tensions, le contentieux autour des puces modem des iPhone touche enfin à son terme. Apple reprochait à Qualcomm une forme de « double facturation » : le fabricant de semi-conducteurs vendait ses puces radio tout en exigeant, en parallèle, le paiement de licences sur ses brevets. Au cœur du litige figurait […]
Suivez iPhoneAddict.fr sur Facebook, et suivez-nous sur Twitter
N'oubliez pas de télécharger notre Application gratuite iAddict pour iPhone et iPad (lien App Store)
L’article Apple vs Qualcomm : fin de la bataille judiciaire sur les redevances « double facturation » est apparu en premier sur iPhoneAddict.fr.
Apple déploie Apple Music Connect, un nouvel espace en ligne entièrement dédié aux labels, distributeurs et partenaires de l’industrie musicale. L’objectif est de centraliser les outils promotionnels et de mieux orchestrer la mise en avant des artistes sur Apple Music. Cette nouvelle plateforme permet de gérer les visuels officiels, d’envoyer des photos de presse et […]
Suivez iPhoneAddict.fr sur Facebook, et suivez-nous sur Twitter
N'oubliez pas de télécharger notre Application gratuite iAddict pour iPhone et iPad (lien App Store)
L’article Apple Music Connect : Apple lance une nouvelle plateforme marketing pour les labels et les distributeurs est apparu en premier sur iPhoneAddict.fr.
Apple vient d’obtenir un brevet majeur consacré à l’obfuscation des données 3D, une technologie pensée pour protéger la vie privée dans les environnements de réalité augmentée. Derrière cet enregistrement se dessine une vision claire : faire de la confidentialité le socle du spatial computing, au moment où le Vision Pro ouvre la voie à des […]
Suivez iPhoneAddict.fr sur Facebook, et suivez-nous sur Twitter
N'oubliez pas de télécharger notre Application gratuite iAddict pour iPhone et iPad (lien App Store)
L’article Apple dépose un brevet clé sur la confidentialité en réalité augmentée est apparu en premier sur iPhoneAddict.fr.
Synthetic materials such as plastics are designed to be durable and water resistant. But the processing required to achieve these properties results in a lack of biodegradability, leading to an accumulation of plastic pollution that affects both the environment and human health. Researchers at the Institute for Bioengineering of Catalonia (IBEC) are developing a possible replacement for plastics: a novel biomaterial based on chitin, the second most abundant natural polymer on Earth.
“Every year, nature produces on the order of 1011 tonnes of chitin, roughly equivalent to more than three centuries of today’s global plastic production,” says study leader Javier G Fernández. “Chitin and [its derivative] chitosan are the ultimate natural engineering polymers. In nature, variations of this material produce stiff insect wings enabling flight, elastic joints enabling extraordinary jumping in grasshoppers, and armour-like protective exoskeletons in lobsters or clams.”
But while biomaterials provide a more environmentally friendly alternative to conventional plastics, most biological materials weaken when exposed to water. In this latest work, Fernández and first author Akshayakumar Kompa took inspiration from nature and developed a new biomaterial that increases its strength when in contact with water, while maintaining its natural biodegradability.
In the exoskeletons of insects and crustaceans, chitin it is secreted in a gel-like form into water and then transitions into a hard structure. Following a chance observation that removing zinc from a sandworm’s fangs caused them to soften in water, Kompa and Fernández investigated whether adding a different transition metal, nickel, to chitosan could have the opposite effect.
By mixing nickel chloride solution (at concentrations from 0.6 to 1.4 M) with dispersions of chitosan extracted from discarded shrimp shells, the researchers entrapped varying amounts of nickel within the chitosan structure. Fourier-transform infrared spectra of resulting chitosan films revealed the presence of nickel ions, which form weak hydrogen bonds with water molecules and increase the biomaterial’s capacity to bond with water.
“In our films, water molecules form reversible bridges between polymer chains through weak interactions that can rapidly break and reform under load,” Fernández explains. “That fast reconfiguration is what gives the material high strength and toughness under wet conditions: essentially a built-in, stress-activated ‘self-rearrangement’ mechanism. Nickel ions act as stabilizing anchors for these water-mediated bridges, enabling more and longer-range connections and making inter-chain connectivity more robust”.
The nickel-doped chitosan samples had tensile strengths of between 30 and 40 MPa, similar to that of standard plastics. Adding low concentrations of nickel did not significantly impact the mechanical properties of the films. Concentrations of 1 M or more, however, preserved the material’s strength while increasing its toughness (the ability to stretch before breaking) – a key goal in the field of structural materials and a feature unique to biological composites.
Upon immersion in water, the nickel-doped films exhibited greater tensile strength, increasing from 36.12±2.21 MPa when dry to 53.01±1.68 MPa, moving into the range of higher-performance engineering plastics. In particular, samples created from an optimal 0.8 M nickel concentration almost doubled in strength when wet (and were used for the remainder of the team’s experiments).
The manufacturing process involves an initial immersion in water, followed by drying for 24 h and then re-wetting. During the first immersion, any nickel ions that are not incorporated into the material’s functional bridging network are released into the water, ensuring that nickel is present only where it is structurally useful.
The researchers developed a zero-waste production cycle in which this water is used as a primary component for fabricating the next object. “The expelled nickel is recovered and used to make the next batch of material, so the process operates at essentially 100% nickel utilization across batches,” says Fernández.
They used this process to produce various nickel-doped chitosan objects, including watertight containers and a 1 m2 film that could support a 20 kg weight after 24 h of water immersion. They also created a 244 x 122 cm film with similar mechanical behaviour to the smaller samples, demonstrating the potential for rapid scaling to ecologically relevant scales. A standard half-life test revealed that after approximately four months buried in garden soil, half of the material had biodegraded.
The researchers suggest that the biomaterial’s first real-world use may be in sectors such as agriculture and fishing that require strong, water-compatible and ultimately biodegradable materials, likely for packaging, coatings and other water-exposed applications. Both nickel and chitosan are already employed within biomedicine, making medicine another possible target, although any new medical product will require additional regulatory and performance validation.
The team is currently setting up a 1000 m2 lab facility in Barcelona, scheduled to open in 2028, for academia–industry collaborations in sustainable bioengineering research. Fernández suggests that we are moving towards a “biomaterial age”, defined by the ability to “control, integrate, and broadly use biomaterials and biological principles within engineering applications”.
“Over the last 20 years, working on bioinspired manufacturing, we have been able to produce the largest bioprinted objects in the world, demonstrated pathways for resource-secure and sustainable production in urban environments, and even explored how these approaches can support interplanetary colonization,” he tells Physics World. “Now we are achieving material properties that were considered out of reach by designing the material to work with its environment, rather than isolating itself from it.”
The researchers report their findings in Nature Communications.
The post Nickel-enhanced biomaterial becomes stronger when wet appeared first on Physics World.
© Evelyn Hockstein/REUTERS
Après avoir été la cible d'une cyberattaque sur la chaîne d'approvisionnement, Notepad++ renforce son processus de mise à jour avec un double verrouillage.
Entre le natif avec TAA, le NVIDIA DLSS 4.5 et l’AMD FSR Upscaling (FSR 4), quelle méthode offre la meilleure qualité d’image en UHD ? C’est la question à laquelle ont voulu répondre nos confrères de ComputerBase... [Tout lire] 
Besoin de renouveler votre équipement sans exploser votre budget ? Jusqu’au 4 mars, Cdiscount lance une offensive sur les prix avec des alertes immanquables sur une sélection de produits souvent bien moins chers qu’ailleurs.
Les alimentations SFX ne sont plus des solutions de niche réservées à quelques configurations miniatures un peu exotiques. Aujourd’hui, elles se démocratisent et nous avons testé la C850 SFX de NZXT.
Cet article Test C850 SFX de NZXT a été publié en premier par GinjFo.
Un vent de panique a soufflé sur un site de production du Rafale, avant de se dissiper aussi vite qu'il était apparu. L'affaire de l'intérimaire soupçonné d'espionnage s'est finalement dégonflée, révélant une simple maladresse aux conséquences néanmoins réelles.
Moon Beast Productions, studio fondé par des vétérans de Diablo, secoue le monde de l'ARPG. Le jeu Darkhaven lance sa campagne Kickstarter pour lever 500 000 $ et, fait rare, propose une démo pré-alpha "non filtrée" sur Steam. Une promesse de transparence et d'innovation pour un monde totalement destructible.
Connexion
