Structural relaxation can be induced by annealing and usually leads to embrittlement in metallic glasses (MGs). Here, we show that a relaxed MG obtained an as-cast at temperature (annealing temperature, Ta) below its fictive suitably rejuvenated thermal treatment of the higher than Ta. The effect is driven enthalpy relaxation, endothermic reaction upon heating MG. This rejuvenation lifts energy...

Many food materials exist in a disordered amorphous solid state due to processing. Therefore, understanding the concept of amorphous state, its important phase transition (i.e., glass transition), and the related phenomena (e.g., enthalpy relaxation) is important to food scientists. Food saccharides, including mono-, di-, oligo-, and polysaccharides, are among the most important major component...

A series of experiments was performed on high-enthalpy effects on hypersonic boundary-layer transition using nitrogen, air, and carbondioxideas test gases in the T5 hypervelocity shock tunnel.Previous experiments on a sharp cone showed signiŽ cant high enthalpy effects. This series concerns the attachment line boundary layer on swept cylinders with sweep angles of 60 and 45 deg. The observed tr...

The enthalpy relaxation is performed in the glassy Ge22Se78 to understand the dynamic behaviors. The structure of the glass is examined by X-ray diffraction and Raman spectra. The dynamic parameters such as the fragility, stretching exponent and non-linear factor are determined. A low fragility of m = 27 is exhibited for the chalcogenide, however, the stretching exponent is found not to have a ...

Viscosity and enthalpy relaxation from the amorphous state into the supercooled liquid state was investigated in the bulk metallic glass forming Zr46.75Ti8.25Cu7.5Ni10Be27.5 alloy below the calorimetric glass transition. At different temperatures, the viscosities relax into states that obey the same Vogel–Fulcher–Tammann relation as the data obtained at higher temperatures in the supercooled li...

Constitutive equations are derived for enthalpy recovery in polymeric glasses after thermal jumps. The model is based on the theory of cooperative relaxation in a version of the trapping concept. It is demonstrated that some critical temperature Tcr and some critical degree of crystallinity fcr exist in a semicrystalline polymer above which the energy landscape becomes homogeneous and structura...

In this paper, the basic constitutive equations and equations of motion are derived to describe the behavior of thermoelastic porous piezoelectric medium by using Biot’s theory and the theory of generalized thermoelasticity with on relaxation time (Lord-Shulman). The electrical enthalpy density function is derived in the general coordinates. Also, clear definitions for the poroelastic modulus, ...