An analytical model of non-Gaussian energy landscape of low-temperature fluids is developed based on the thermodynamics of the fluid of dipolar hard spheres. The entire excitation profile of the liquid, from the high-temperature liquid to the point of ideal-glass transition, has been obtained from Monte Carlo simulations. The fluid of dipolar hard spheres loses stability close to the point of i...

Molecular dynamics (MD) simulation provides a unique window into the microscopic processes controlling the properties of amorphous silicates of geochemical importance. Of special interest are changes in structure and dynamics around the glass transition temperature. Seventeen simulations for composition CaAl2Si2O8 in a microcanonical ensemble of 1300 particles (O + Si + Al + Ca) were conducted ...

The transition taking place between two metastable phases in 2-O-adamantane, namely the F m3̄m cubic, rotator phase and the lower temperature P 21/c, Z = 4 substitutionally disordered crystal is studied by means of muon spin rotation and relaxation techniques. Measurements carried out under zero, weak transverse and longitudinal fields reveal a temperature dependence of the relaxation parameters...

We study the microstructural glass transition in diblock-copolymer melts using a thermodynamic replica approach. Our approach performs an expansion in terms of the natural smallness parameter--the inverse of the scaled degree of polymerization N--which allows us to systematically study the approach to mean-field behavior as the degree of polymerization increases. We find that in the limit of in...

The objective of this research was to study the effect of water activity and glass transition temperature on the fat hydrolysis in a food model system. The model system was prepared with tapioca starch, casein, palm oil and sugar as 58, 14, 16 and 12 g/100 g model matrix, respectively. Hydrolysis reaction was accelerated by commercial lipase at six levels of water content and water activity. Mo...

A fundamental problem of glass transition is to provide a quantitative and microscopic explanation of the heat-capacity jump at the glass transition temperature Tg . Similar problems are also common to other disordered systems, including spin glasses. We propose that the jump of heat capacity at Tg takes place as a result of the change of the liquid’s elastic, vibrational, and thermal propertie...

The dielectric loss spectra of a series of copolyesters of poly(ethylene terephthalate) and poly(ethylene isophthalate) have been measured as a function of temperature in a broad frequency range (10(-1)-10(9) Hz). By these measurements, the merging of the two relevant relaxations alpha and beta has been studied. The beta processes exhibit a complex temperature dependence, showing a clear Arrhen...

Cyclic olefin copolymers comprise a new class of polymeric materials showing properties of high glass-transition temperature, optical clarity, low shrinkage, low moisture absorption, and low birefringence. There are several types of cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. In this work, we have analyzed the chemical structure of the curren...

We combine the hypernetted chain approximation of liquid state theory with the mode-coupling theory of the glass transition to analyze the structure and dynamics of soft spheres interacting via harmonic repulsion. We determine the locus of the fluid-glass dynamic transition in a temperature--volume fraction phase diagram. The zero-temperature (hard-sphere) glass transition influences the dynami...

Glass transition and relaxation of the glycerol-water binary mixture system are studied over the glycerol concentration range of 5 85 mol% using the highly sensitive technique of spin probe ESR. For the water rich mixture the glass transition, sensed by the spin probe, arises from the vitrified mesoscopic portion of the binary system. The concentration dependence of the glass transition tempera...