A theoretical study of the nucleation, size, and structure of diamond phase carbon clusters on Si~111! substrates is presented. Molecular mechanics analysis has been utilized to predict energetically and entropically feasible pathways for nucleation of the carbon clusters. Several mechanistic pathways for nucleation of carbon clusters are examined with CH3 and/or C2H2 as the nucleation precurso...

A large variation is observed in induction times measured under equal conditions in 1 ml solutions. Ruling out experimental errors, this variation originates from the nucleation process. The induction time distribution is explained by the stochastic nature of nucleation if the number of nuclei formed is approaching 1 per vial. Accurate heterogeneous crystal nucleation rates were determined from...

We present results from direct, large-scale molecular dynamics simulations of homogeneous bubble (liquid-to-vapor) nucleation. The simulations contain half a billion Lennard-Jones atoms and cover up to 56 million time steps. The unprecedented size of the simulated volumes allows us to resolve the nucleation and growth of many bubbles per run in simple direct micro-canonical simulations while th...

The multivariate analysis of nucleation rate dependency on vapor concentration, initiated in Part I [McGraw and Zhang, 2007], is extended to include temperature. Nucleation rate sensitivity to changes in vapor concentration and temperature are described using kinetic extensions of the nucleation theorem (KNTs). The nucleation rate is found to be highly multi-linear in selected KNT-suggested tem...

Kinetic extensions of the nucleation theorem ~KNT! are derived using the law of mass action and detailed balance. Results are obtained for the firstand higher-order derivatives of the nucleation rate, J, with change in supersaturation, S, in terms of the cumulants, kn , of a molecular distribution of reciprocal equilibrium cluster growth rates. At constant temperature we find d ln J/d ln S5k1 1...

[1] Particle number concentration in the troposphere is an important parameter controlling the climate and health impacts of atmospheric aerosols. We show that nucleation rates and total particle number concentrations in the troposphere, predicted by different nucleation schemes, differ significantly. Our extensive comparisons of simulated results with land‐, ship‐, and aircraft‐based measureme...

Noncentrosomal microtubule (MT) nucleation at the Golgi generates MT network asymmetry in motile vertebrate cells. Investigating the Golgi-derived MT (GDMT) distribution, we find that MT asymmetry arises from nonrandom nucleation sites at the Golgi (hotspots). Using computational simulations, we propose two plausible mechanistic models of GDMT nucleation leading to this phenotype. In the "coope...

aggregation of pharmaceutical proteins reduces the efficiency and increases the cost of production. it can also lead to the reduced efficacy of drug or cause side effects on the patient’s body. investigating how to create them plays an important role to find agents that prevents the aggregation. this study was allocated for understanding the mechanism of formation of the reteplase protein using...

We use Monte Carlo simulations of the Lennard-Jones model to study the nucleation of a crystal phase at a flat surface. Our motivation is the observation that crystal phases almost always nucleate at a surface. We find that a surface phase transition (prefreezing) can control nucleation of the bulk crystal. This finding should be general and so surface phase behavior should be considered whenev...

Sulphuric acid and organic vapours have been identified as the key components in the ubiquitous secondary new particle formation in the atmosphere. In order to assess their relative contribution and spatial variability, we analysed altogether 36 new particle formation events observed at four European measurement sites during EUCAARI campaigns in 2007–2009. We tested models of several different ...