Dental microwear has been used for decades to reconstruct the diets of fossil hominins and bioarchaeological populations. The basic theory that hard-brittle foods (e.g., nuts, bone) require crushing leave pits as they are pressed between opposing cheek-tooth surfaces, whereas soft-tough grass blades, meat) shearing scratches dragged along surfaces slide past one another. However, recent studies have called into question efficacy an indicator diet. One issue limited number in vitro providing...

The nanoscale responses of teeth to chewing loads are poorly understood. This has contributed debate concerning the aetiology enamel wear and resistance fracture. Here we develop a new model for reactions individual hydroxyapatite nanofibres varying directions force. Hydroxyapatite nanofibres, or crystallites, composed chains bonded nanospheres, fundamental building blocks enamel. study indicates that these respond contact pressure in three distinct ways depending on force magnitude...

High Temperature may exert a great impact on the service life and reliability of friction materials during sliding. Tribological behavior new developed copper metal matrix composite (Cu-MMC) against steel disc was investigated using home-built pin-on-disc tribometer in ambient temperature range 25–800 °C. Detailed analyses worn surfaces subsurfaces were performed scanning electron microscope, optical X-ray diffractometer 3D profiler. The surface Cu-MMC exhibited different features at various...

The rapid development of stretchable electronics made by circuits, microchips, and encapsulation elastomers has caused the production a large amount electronic waste (e‐waste). degradation can highly minimize negative effects e‐wastes. However, chemicals that included acid, alkali, organics were repeatedly used during recycling process, which environmentally unfriendly. Here, water‐modulation‐degradation‐reconstruction (WDR) polyvinylpyrrolidone (PVP)‐honey composite (PHC) polymer‐gel was...

This study explored the development of polyvinylpyrrolidone (PVP)–honey-gel (PHG) through 3D printing, aiming to develop a multifunctional bio-tape with adhesive and degradable properties. Based on potential honey promote wound healing due its antibacterial anti-inflammatory properties, PVP–honey-based printing ink was developed by combining PVP create PHG technology that can form film strong adhesion flexibility. First, chemical–physical properties performance were characterized. The line...

Abstract Pore size is critical to the oil storage performance and tribological properties of porous polyimide (PPI). To study effect pore size, four PPIs with different sizes similar porosities were fabricated. The mechanical, oil-absorption investigated. According results, larger pores demonstrate faster absorption a higher oil-filling rate. However, contribute rougher surface lower retention. These dual effects result in displaying low friction coefficient at speeds but high speeds. on EHD...

ABSTRACT The development of metal implants as permanent replacements for hard tissue involves careful consideration both interfacial bone integration load‐bearing support and energy dissipation to prevent resorption due excess load. Currently, most are typically limited excelling in only one these functions. A promising approach achieving a synergistic effect is the design nanofiber‐chitosan (nanofiber‐CS) composite flexible coating on titanium alloy surfaces. However, tribological...

Abstract Stretchable electronics have the unique capability of 3D (three dimensional) deformation, overcoming brittleness traditional inorganic electronics. However, during large deformations, different scale strains between rigid and stretchable components lead to mismatch, causing interconnect failures. Therefore, development rigidity‐programmable substrate with effective strain shielding capabilities has become a research hotspot. Furthermore, exponential growth in electronic density...

Exogenous grit adherent to the surface of food items and fracture properties have each been considered important factors contributing pattern degree tooth wear in mammals. However, interactions between these two generating distinctive microwear textures remained understudied. Here authors revisit in-vitro results from simulated chewing explore how physical foods act together create dental on occlusal enamel surfaces. Results suggest that effect exogenous texture is dependent material which...

Tooth enamel is a distinctive nanocomposite with highly organized hierarchical structure made of nanometer- and micrometer-scale building blocks. This has an excellent mechanical function that can last for decades thanks to effective but underexploited interfacial chemical bonding between the In this study, nanomechanical system test (NST), scanning electron microscope (SEM), X-ray diffraction (XRD, including powder XRD or PXRD, small angle SAXRD, grazing incidence GISAXRD), atomic force...

Abstract Porous polyimide (PPI) exhibits good tribological performances due to excellent oil-storage properties. structure could store lubricant but also make PPI materials difficult be strengthened by most fillers, because fillers will destroy the pore and reduce strength significantly. Rare-earth compounds (RECs) have high surface activity, which allow them bond well with polymer. In this study, properties of REC modified PPIs were investigated using a ball-on-disc tribometer, along an...

In this work, we aim to build the mathematical model for delaminated composite plates resting on elastic foundation by means of improved layerwise theory and finite element implementation free vibration analysis. The proposed takes into account transverse normal shear deformation so as investigate their effect dynamic characteristics plates. four-node plate is used formulations with Langrage interpolation functions in-plane structural unknowns Hermite cubic out-of-plane unknowns....

A relay selection algorithm was proposed to improve a communication rate of D2D (device-to-device) users in-vehicle networking systems based on social network combined with Q-learning. The scheme divided into two steps. Firstly, threshold introduced filter the potential nodes reduce number probing times user's interest similarity in network. Then, an optimal maximise total links Q-learning algorithm. This method can provide meet requirements vehicle communication. simulation results showed...

Bone adapts to habitual loads by remodeling resist stresses that would otherwise break it. The question of whether the same holds for teeth, however, remains unanswered. We might expect species with ever-growing dentitions alter enamel histology in response diet. In this study we fed bamboo rats (Rhizomys sinensis) different foods assess effects on microstructure. Results indicate gnawing fracture-resistant items (i.e., bamboo) produces substantively dental microstructures than does eating...

Abstract The integrated development of stretchable electronics is inevitably led to an increase in the density electronic components, which substantially complexity conductive pathways. This causes substantial challenges circuit design. Therefore, formation a three‐dimensional (3‐D) cross‐bridge wire interconnection structure vital significance for high‐density devices. To fulfill this requirement, study introduces low‐temperature liquid metal (LM)‐based 3‐D printing technology, can print...

ABSTRACT Porous polyimide (PPI) possesses interconnected micro‐pores capable of storing lubricant oil. However, the strength PPI was weakened by pores, resulting in a decrease wear resistance. Herein, organic silicon coating (OSC) used to strengthen surfaces. The oil storage capacity and tribological performance coated with varying coverages were investigated. Results demonstrated that surfaces effectively protected OSC. Particularly noteworthy substantial reduction friction coefficient 50.9...