Engineering topics
Yau, S.-T.
Publications and source records attributed to Yau, S.-T..
Dissipating Step Bunches during Crystallization under Transport Control
In studies of crystal formation by the generation and spreading of layers, equidistant step trains are considered unstable---bunches and other spatiotemporal patterns of the growth steps are viewed as ubiquitous. We provide an example to the opposite. We monitor the spatiotemporal dynamics of steps and the resulting step patterns during crystallization of the proteins ferritin and apoferritin using the atomic force microscope. The variations in step velocity and density are not correlated, indicating the lack of a long-range attraction between the steps. We show that (i) because of its coupling to bulk transport, nucleation of new layers is chaotic and occurs at the facet edges, where the interfacial supersaturation is higher; (ii) step bunches self-organize via the competition for supply from the solution; and, (iii) bunches of weakly interacting steps decay as they move along the face. Tests by numerical modeling support the conclusions about the mechanisms underlying our observations. The results from these systems suggest that during crystallization controlled by transport, with weakly or noninteracting growth steps, the stable kinetic state of the surface is an equidistant step train, and step bunches only arise during nucleation of new layers. Since nucleation only occurs at a few sites on the surface, the surface morphology may be controllably patterned or smoothened by locally controlling nucleation.
Fundamentals and Control Strategies for Nucleation of Protein Crystals in Solution
No abstract available
Fundamental Aspects of Nucleation Theory in the Formation of Protein Crystals
No abstract available
What Would Gibbs Do If he Were Thinking of Nucleation of Protein Solid Phases
No abstract available
Solvent Entropy Contribution to the Free Energy of Protein Crystallization
No abstract available
Nonlinear Dynamics and Pattern Formation on the Growth Interfaces of Protein Crystals
No abstract available
Defect Formation During Crystallization of Ferritins: Molecular Mechanisms
No abstract available
Characteristic Lengthscales of the Protein Crystallization Processes: Where Can Gravity Affect Growth
No abstract available
Tracking Individual Molecules as they Attach Themselves to Crystals: Statistics, Dynamics and Mechanisms
No abstract available
Molecular-Resolution Atomic Force Microscopy Movies of Step Propragation around Surface Defects and Impurities
No abstract available
Lower Incorporation of Impurities in Ferritin Crystals by Suppression of Convection: Modeling Results
No abstract available
Molecular-Level Parameters for the Self Assembly of Biological Macromolecules into Crystals
No abstract available
Direct Observation of Nucleus Structure and Nucleation Pathways
No abstract available