Biomedical subjects

P J Upton

Publications and source records attributed to P J Upton.

3 recordsLinked to original sources

PubMed2006

Step dynamics on vicinal surfaces using discrete interface models.

Fluctuations of a single step on a vicinal surface are investigated using a discrete model designed to go further in capturing atomistic effects than usually achieved with continuum models. Variants of the model to incorporate the following three types of adatom dynamics are studied: attachment-detachment; periphery (step-edge) diffusion; and terrace diffusion. The dynamic exponent z is determined for each type as well as crossover functions joining three distinct scaling regimes.

Journal Article↗

PubMed2001

Local-functional theory of critical adsorption.

Local-functional methods are applied to critical adsorption in three-dimensional Ising-like systems. The universal order-parameter-profile scaling functions, P(+/-)(x), along the critical isochore (+) and phase boundary (-), are calculated along with their associated universal amplitudes. Good agreement is found with the results of Monte Carlo simulations. General properties of P(+/-)(x) for small and large scaled distance, x, are elucidated. An order-parameter scaling function, P(c)(x), for critical adsorption along the critical isotherm is introduced and calculated.

Journal Article↗

PubMed1999

Exact interface model for wetting in the planar Ising model.

At the wetting transition in the two-dimensional Ising model the long contour (interface) gets depinned from the substrate. It is found that on sufficiently large length scales the statistics of the long contour are described by a unique probability measure corresponding to a continuous "interface model" with an interface binding "potential" given by a Dirac delta function supported on the substrate. A lattice solid-on-solid model is shown to give similar results.

Journal Article↗