Suchergebnisse

After a brief presentation of the general scenario to which the note is connected, the equations involved in some processes related to gastronomy and cuisine activity are derived, only by resorting to dimensional analysis. It is shown how the meat cooking time, or that one for spaghetti preparation can be quantitatively calculated on the basis of the heat conduction or thermal diffusion equations. The processes involved in baking of a good pizza (particularly in a wood oven!) or brewing a good coffee are addressed on the basis of scientific approaches.

After a brief introduction to thermodynamical superconducting fluctuations, some experimental results in different systems are presented. Superconducting fluctuations were predicted and revealed in nanoparticles of conventional superconductors since late 60s. However, just in the last two decades phenomena related to an anomalous diamagnetism have been discovered in high-Tc underdoped compounds, mainly by collecting the isothermal magnetization curves above the critical temperature Tc. These experimental data can be interpreted in terms of fluctuations of the phase of the order parameter and a related theoretical model can explain the results in cuprates, pnictides and Fe-based materials. Such results, here presented together with preliminary data on a Ca-based high-Tc system, allow one to extract a fundamental parameter, the upturn magnetic field above which the diamagnetic magnetization initiates to decrease on increasing the field. Its temperature dependence distinguishes among diamagnetic effects related to superconducting phase fluctuations and to analogous effects due to chemical inhomogenities.