Properties of protective oxide scales containing cerium on Incoloy 800H in oxidizing and sulfidizing environments. I. Constant-extension-rate study of mechanical properties

The mechanical properties of ceramic coatings containing cerium oxide, prepared by the sol-gel method and used to protect Incoloy 800H against aggressive environments, are reported. Deformation and cracking behavior in oxidizing and sulfidizing environments has been investigated by constant-extension-rate tests. Extension rates were between 9.3×10−6 and 3.7×10−7 sec−1 at 823 <T<973 K. Under these conditions, cerium oxide sol-gel-coated specimens do not show any failure at extensions of 1.0% or more, but in hydrogen, sulfide failure is found at lower extensions than in air

Progress in philosophy:a defense of Philosophical Skepticism

An important question about philosophy itself is whether philosophy is making any scientific progress. That philosophy makes progress, like the other sciences, is problematic at first sight. Indeed, empirical research shows that there is hardly any consensus among philosophers about which theories are correct and which are not.To get a better grip on this subject, I analyzed philosophical practice and used this analysis to defend a form of skepticism. Philosophizing does not lead to the expansion of our philosophical knowledge nor to an objective and universally acceptable justification of philosophical positions. This is because there is no collection of reliable philosophical data that can serve as a knowledge foundation or touchstone of philosophical theories. The acceptance of philosophical theories is therefore not only based on what the theory says, but also on the values of the person who is considering the position.This work is not a call to stop philosophizing, although I argue for philosophical skepticism. Instead, I argue that by articulating philosophical problems we can get a clear picture of what we value above all else and what ideas we are willing to give up in favor of others. The end product of philosophical practices may not be knowledge of the world, but it does consist of knowledge of ourselves and the society in which we live