The assumption of adult roles in the UK, the US, and Finland: Antecedents and associated levels of well-being and health

<p>(a) Vita master, (b) Vita VMK95, (c) Ceramco 3, (d) Kiss, and (e) Vintage.</p

Investigation on the Tribological Behavior and Wear Mechanism of Five Different Veneering Porcelains

<div><p>Objectives</p><p>The primary aim of this research was to investigate the wear behavior and wear mechanism of five different veneering porcelains.</p><p>Methods</p><p>Five kinds of veneering porcelains were selected in this research. The surface microhardness of all the samples was measured with a microhardness tester. Wear tests were performed on a ball-on-flat PLINT fretting wear machine, with lubrication of artificial saliva at 37°C. The friction coefficients were recorded by the testing system. The microstructure features, wear volume, and damage morphologies were recorded and analyzed with a confocal laser scanning microscope and a scanning electron microscope. The wear mechanism was then elucidated.</p><p>Results</p><p>The friction coefficients of the five veneering porcelains differ significantly. No significant correlation between hardness and wear volume was found for these veneering porcelains. Under lubrication of artificial saliva, the porcelain with higher leucite crystal content exhibited greater wear resistance. Additionally, leucite crystal size and distribution in glass matrix influenced wear behavior. The wear mechanisms for these porcelains were similar: abrasive wear dominates the early stage, whereas delamination was the main damage mode at the later stage. Furthermore, delamination was more prominent for porcelains with larger crystal sizes.</p><p>Significance</p><p>Wear compatibility between porcelain and natural teeth is important for dental restorative materials. Investigation on crystal content, size, and distribution in glass matrix can provide insight for the selection of dental porcelains in clinical settings.</p></div

Friction coefficients of five dental veneering porcelains under artificial saliva environment.

<p>Friction coefficients of five dental veneering porcelains under artificial saliva environment.</p

Surface micrographs of five porcelains etched with 2.5% hydrofluoric acid for 30 s.

<p>(a) Vita master, at a magnification of ×2000; (b) Vita master, at a higher magnification of ×20000; (c) Kiss, at a magnification of ×2000; (d) Kiss, at a higher magnification of ×20000; (e) Vita VMK95, at a magnification of ×2000; (f) Vita VMK95, at a higher magnification of ×20000; (g) Vintage, at a magnification of ×2000; (h) Vintage, at a higher magnification of ×20000; (i) Ceramco 3, at a magnification of ×2000; (j) Ceramco 3, at a higher magnification of ×20000.</p

Mean hardness and wear volume of five kinds of dental veneering porcelains.

<p>Mean hardness and wear volume of five kinds of dental veneering porcelains.</p

Hardness and wear volume of five dental veneering porcelains.

<p>Hardness and wear volume of five dental veneering porcelains.</p

Rotating-Disk-Based Hybridized Electromagnetic–Triboelectric Nanogenerator for Sustainably Powering Wireless Traffic Volume Sensors

Wireless traffic volume detectors play a critical role for measuring the traffic-flow in a real-time for current Intelligent Traffic System. However, as a battery-operated electronic device, regularly replacing battery remains a great challenge, especially in the remote area and wide distribution. Here, we report a self-powered active wireless traffic volume sensor by using a rotating-disk-based hybridized nanogenerator of triboelectric nanogenerator and electromagnetic generator as the sustainable power source. Operated at a rotating rate of 1000 rpm, the device delivered an output power of 17.5 mW, corresponding to a volume power density of 55.7 W/m³ (<i>P</i>_d = <i>P</i>/<i>V</i>, see Supporting Information for detailed calculation) at a loading resistance of 700 Ω. The hybridized nanogenerator was demonstrated to effectively harvest energy from wind generated by a moving vehicle through the tunnel. And the delivered power is capable of triggering a counter <i>via</i> a wireless transmitter for real-time monitoring the traffic volume in the tunnel. This study further expands the applications of triboelectric nanogenerators for high-performance ambient mechanical energy harvesting and as sustainable power sources for driving wireless traffic volume sensors

Self-Powered Safety Helmet Based on Hybridized Nanogenerator for Emergency

The rapid development of Internet of Things and the related sensor technology requires sustainable power sources for their continuous operation. Scavenging and utilizing the ambient environmental energy could be a superior solution. Here, we report a self-powered helmet for emergency, which was powered by the energy converted from ambient mechanical vibration via a hybridized nanogenerator that consists of a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG). Integrating with transformers and rectifiers, the hybridized nanogenerator can deliver a power density up to 167.22 W/m³, which was demonstrated to light up 1000 commercial light-emitting diodes (LEDs) instantaneously. By wearing the developed safety helmet, equipped with rationally designed hybridized nanogenerator, the harvested vibration energy from natural human motion is also capable of powering a wireless pedometer for real-time transmitting data reporting to a personal cell phone. Without adding much extra weight to a commercial one, the developed wearing helmet can be a superior sustainable power source for explorers, engineers, mine-workers under well, as well as and disaster-relief workers, especially in remote areas. This work not only presents a significant step toward energy harvesting from human biomechanical movement, but also greatly expands the applicability of TENGs as power sources for self-sustained electronics