We investigate the effects of the frequency and density of a nanomechanical stimulus on nucleation and growth of silk-elastin-like protein polymer (SELP) nanofibers. Repetitive tappings are crucial to create nucleation areas and a potential molecular level mechanism was proposed. Using this technique mechanically guided nanofiber patterns were successfully created.

To investigate the effect of growth area on interface dislocation density in strained-layer epitaxy, we have fabricated 2-.um-high mesas of varying lateral dimensions and geometry in (001) GaAs substrates with dislocation densities of 1.5 X 10\ 10, and 10 cm-2 • 3500-, 7000-, and 8250-A-thick Ino (J5 Gao 95 As layers, corresponding to 5, to, and 11 times the experimental critical layer thicknes...

Physical and biochemical aspects of protein crystal nucleation can be distinguished in an appropriately designed experimental setting. From a physical perspective, the diminishing number of nucleation-active particles (and/or centers), and the appearance of nucleation exclusion zones, are two factors that act simultaneously and retard the initially fast heterogeneous nucleation, thus leading to...

We analyze the effect of primordial density perturbations on the cosmic QCD phase transition. According to our results hadron bubbles nucleate at the cold perturbations. We call this mechanism inhomogeneous nucleation. We find the typical distance between bubble centers to be a few meters. This exceeds the estimates from homogeneous nucleation by two orders of magnitude. The resulting baryon in...

Electrochemical nucleation at a liquid j liquid interface has been studied by cyclic voltammetry and galvanostatic measurements. A model of general applicability to any current/potential transient was developed for three-dimensional nucleation and growth, yielding information on particle number density. The experimental data was analyzed with this model. # 2002 Elsevier Science B.V. All rights ...

Density-functional theory is used to study homogeneous bubble nucleation in the stretched Lennard-Jones liquid. We show that the ratio of density-functional to classical nucleation theory free energy barriers should scale with the quantity Dm/Dmspin , the difference in chemical potential between the bulk superheated and the saturated liquid divided by the chemical potential difference between t...

With the large differences in surface energy between film and substrate in combination with the low sticking coefficient of hydrocarbon radicals, nanocrystalline diamond growth on foreign substrates typically results in poor nucleation densities. A seeding technique is therefore required to realize pinhole-free and thin coalesced films. In this work, a chemical nucleation method for growth of d...

The squared-gradient approximation to the modified-core Van der Waals density functional theory model is developed. A simple, explicit expression for the SGA coefficient involving only the bulk equation of state and the interaction potential is given. The model is solved for planar interfaces and spherical clusters and is shown to be quantitatively accurate in comparison to computer simulations...

Boiling heat transfer is a key thermal limit in nuclear systems. However, for decades, its modeling has relied on speculative hypotheses and a good dose of empiricism. As researchers now start to develop more mechanistic models, the need for high-quality high-resolution data on the bubble nucleation and growth cycle is increasing. Specifically, nucleation site density, bubble departure diameter...

We show that low area density Ge/Si(100) island ensembles comprised solely of hut and pyramid clusters do not undergo Ostwald ripening during days-long growth temperature anneals. In contrast, a very low density of large, low chemical potential Ge islands reduce the supersaturation causing the huts and pyramids to ripen. By assuming that huts lengthen by adding single {105} planes that grow fro...