A study was undertaken to evaluate the effect of artificial aging through steam and thermal treatment as influencing the shear bond strength between three different commercially available zirconia core materials, namely, Upcera, Ziecon, and Cercon, layered with VITA VM9 veneering ceramic using Universal Testing Machine. The mode of failure between zirconia and ceramic was further analyzed as ad...

The physical properties of γ-ray-irradiated and thermally aged Poly(ether ether ketone) (PEEK) have been investigated. To evaluate the degradation level of PEEK, analyses of the mechanical, electrical, and dielectric relaxation properties were carried out for accelerated-aged PEEK. Studies of the temperature dependency of the dielectric properties indicated that the glass transition temperature...

We investigate the validity of a zeroth thermodynamic law for nonequilibrium systems. In order to describe the thermodynamics of the glassy systems, it has been introduced an extra parameter, the effective temperature which generalizes the fluctuation-dissipation theorem (FDT) to off-equilibrium systems and supposedly describes thermal fluctuations around the aging state. In particular we analy...

The influence of the atomic order on the martensitic transformation entropy change has been studied in a Ni-Mn-In-Co metamagnetic shape memory alloy through the evolution of the transformation temperatures under high-temperature quenching and post-quench annealing thermal treatments. It is confirmed that the entropy change evolves as a consequence of the variations on the degree of L21 atomic o...

SnAgCu is one of the most promising candidates for lead-free solders to replace conventional eutectic SnPb solders. The effects of solder volume on interfacial reactions and microstructure evolution in Au/Ni-SnAgCu-Ni(P) solder joints have been investigated under soldering and thermal aging conditions. The results show that solder volume has a strong effect on the formation of Au-containing int...

Precipitate size and number density are two key factors for tailoring the mechanical behavior of nanoscale precipitate-hardened alloys. However, during thermal aging, the precipitate size and number density change, leading to either poor strength or high strength but significantly reduced ductility. Here we demonstrate, by producing nanoscale co-precipitates in composition-optimized multicompon...

The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing....

Thermal washer-disinfectors represent a technology that brought about great advantages such as, establishment of protocols, standard operating procedures, reduction in occupational risk of a biological and environmental nature. The efficacy of the cleaning and disinfection obtained by automatic washer disinfectors machines in running programs with different times and temperatures determined by ...

PURPOSE This study aimed to present the clinical applicability of restorations fabricated by a new method, by comparing the bond strength of between ceramic powder with different coefficient of thermal expansion and alloys fabricated by Selective laser sintering (SLS). MATERIALS AND METHODS Fifty Co-Cr alloy specimens (25.0 × 3.0 × 0.5 mm) were prepared by SLS and fired with the ceramic (8.0 ...

homogenous charge compression ignition (hcci) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. to avoid excessive pressure rise rate and knocking, hcci engines are fueled with highly diluted mixture using a combination of excess air and/or egr. hcci combustion is attractive due to ext...