In a recent paper [1] Turner et al constructed the free energy per unit volume, G, needed to create a fiber bundle , where G = F − ψ Λ , using continuum elasticity theory. Here F is the distortion free energy per unit volume of a bundle of radius R and pitch length Λ and ψ is a positive Lagrange multiplier that controls the pitch length. From G they predicted the physical properties of the fibe...

A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed. Observations made by sub-angstrom resolution scanning transmission electron microscopy and X-ray probing proved the presence of <110> Sr columns located preferentially at twin boundaries. Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the <110> di...

We study the process of thermal activation mediated by sphaleron transitions by analyzing the real-time dynamics of the decay out of equilibrium in a 1+1 dimensional field theory with a metastable state. The situation considered is that of a rapid supercooling in which the system is trapped in a metastable state at a temperature larger than the mass of the quanta, but smaller than the energy to...

One of the key requirements in semi-crystalline polyesters, synthetic or bio-based, is the control on crystallization rate and crystallinity. One of the limiting factors in the commercialization of the bio-based polyesters, for example polyhydroxyalkanoates synthesized by bacteria for energy storage purposes, is the slow crystallization rate. In this study, we show that by tailoring the molecul...

Umbrella sampling Monte Carlo simulations are used to calculate free energy barriers to homogeneous liquid–vapor nucleation in the superheated Lennard-Jones fluid. The calculated free energy barriers decrease with increased superheating and vanish at the spinodal curve. A statistical geometric analysis reveals the existence of two types of voids: Small interstitial cavities, which are present e...

In this study, effects of heterogeneous nucleation site particles on density, microstructure and hardness were studied in the pure aluminum samples additively manufactured by laser-based powder bed fusion (PBF-LB) method with a small amount TiC particles. It was found that higher density sample addition also containing 1.0 vol% has most refined microstructure. addition, fabricated 0 0.1 have <1...

We explore the free energetics of bubble nucleation in the micellar solution subjected to a negative pressure using a density functional model of a non-ionic surfactant solution. In this two-component model, the solvent is represented by a single hard-core sphere and the surfactant is represented by two tangent hard-core spheres connected by a rigid bond. The attractive interactions between the...