This article investigates and compares the effects of hydrothermal aging on carbon fibre / Elium™ thermoplastic composite vinylester thermoset for marine application. Accelerated tests are performed by immersion in deionised water at 70 °C. Water diffusion, monitored regular weighing, shows that both composites as well resin exhibit non-Fickian behaviour. Analytical models proposed to fit exper...

Non-reversing relaxation enthalpies (∆H nr) at glass transitions T g (x) in the P x Ge x Se 1-2x ternary display a wide, sharp and deep global minimum (~0) in the 0.09 < x < 0.145 range, within which T g becomes thermally reversing. In the reversibility window these glasses are found not to age, in contrast to aging observed for fragile glass compositions outside the window. Thermal reversibili...

The surface degradation of composite resins caused by accelerated aging was studied. Accelerated aging for 900 hours caused erosion of the resin matrices and exposure of filler particles. Differences in surface profiles after aging suggest that the materials eroded at different rates. Accelerated aging may model erosive wear of composites.

BACKGROUND Klotho is an anti-aging protein that is predominantly secreted by the kidneys. OBJECTIVES The aim of the study was to measure and compare the circulating Klotho levels in the serum of trained athletes and in healthy, non-athlete controls. MATERIALS AND METHODS Thirty trained football players were enrolled and their serum Klotho levels were measured the morning after their last ev...

objective(s):some pathologic situations such as diabetes and metabolic syndrome are associated with alternation in nitric oxide level. incidence of these condition increases with aging. on the other hand, insulin secretion is modulated by nitric oxide, and nitric oxide synthase (nos) activity is also altered in diabetes. in this study, modification in the enzyme activity associated with aging a...

Off equilibrium fluctuations in a polymer glass. Abstract The fluctuation-dissipation relation (FDR) is measured on the dielectric properties a polymer glass (polycarbonate). It is observed that the fluctuation dissipation theorem is strongly violated for a quench from above to below the glass transition temperature. The amplitude and the persistence time of this violation are decreasing functi...