orcid.org/0000-0003-4475-4093Working with Lafayette students, I have studied a number of aspects of the growth of dendritic crystals. We have sought to understand the fundamental physics that underlies the growth of these non-faceted crystals, and also to understand how those physical processes interact to produce the beautiful patterns we observe both in the laboratory and in nature.
I am continuing a project originally started by Prof. Emeritus David Hogenboom to study phase equilibria in aqueous solutions at pressures ranging from from 0.1 to 400 MPa. Examples include sodium sulfate, magnesioum sulfate, and methanol. These substances are believed to be an important constituents of some of the icy moons of the outer solar system, such as Europa, one of the moons of Jupiter, and Enceladus and Titan, two of the moons of Saturn. These moons likely contain substantial subsurface oceans. An important goal of this work is to provide volumetric data and high-pressure phase diagrams that can be helpful for understanding the nature of any such subsurface oceans.
We have investigated the motion of an air/water interface as water invades a model porous medium. The static interface shapes can be described as self-affine fractals. The dynamics involve collective "jumps", or "avalanches", and can be studied with ideas gained from the study of self-organized criticality.
Starting in 2001, I worked with Profs. Arthur Kney and Javad Tavakoli to study the behavior of an ion-exchange water purification system in the presence of an applied magnetic field.
Andrew Dougherty
Professor of Physics
Department of Physics
Lafayette College
Easton, PA 18042-1782