Metals at high temperatures

Life at high temperatures.

Water environments with temperatures up to and above boiling are commonly found in association with geothermal activity. At temperatures above 60 degrees C, only bacteria are found. Bacteria with temperature optima over the range 65 degrees to 105 degrees C have been obtained in pure culture and are the object of many research projects. The upper temperature limit for life in liquid water has n...

Nanotribology at high temperatures

Recent molecular dynamics simulation results have increased conceptual understanding of the grazing and the ploughing friction at elevated temperatures, particularly near the substrate's melting point. In this commentary we address a major constraint concerning its experimental verification.

QuantumRatchets at High Temperatures

Using the continued-fraction method we solve the Caldeira-Leggett master equation in the phase-space (Wigner) representation to study Quantum ratchets. Broken spatial symmetry, irreversibility and periodic forcing allows for a net current in these systems. We calculate this current as a function of the force under adiabatic conditions. Starting from the classical limit we make the system quanta...

Latent Fingerprints at High Temperatures

Rate controlling processes in creep of close packed metals at intermediate and high temperatures

New microstructural rate controlling models for high temperature deformation are suggested which are in satisfactory agreement not only with activation parameter values but also with various metallographic observations. Non-compact slip in the HCP and FCC structures can be described by a kink pair mechanism. This process could control dislocation glide through subgrains, and therefore the creep...