Physics & Astrophysics colloquium is Oct. 30 The department of Physics & Astrophysics will host a colloquium at 4 p.m. Friday, Oct. 30, in 211 Witmer Hall. The subject of the colloquium will be Monte Carlo Simulation of the Degradation of Composite Films with Brian Hinderliter, NDSU Coatings and Polymeric Materials department. Abstract: Coatings cover most metal and wood surfaces exposed to environmental weathering, both to protect the underlying material, from corrosion for example, and offer aesthetic improvements. Insights into degradation have been achieved first through Monte Carlo simulations, then through the recognition that many of the property changes are due to the statistical accumulation of vast numbers of small random events. Simulation of coatings and other composite material degradation continues to be productive, not only in generating functional quantitative relationships of measurable properties with time, but also in helping to direct research to improve the technology. The modeling process payoffs include practical benefits such as the ability to interpolate measurements and smooth noisy data based on physically based fitting functions and extrapolate measured data for lifetime prediction or service/maintenance scheduling. Modeling is vital in more fundamental improvements of composite systems such as understanding the physical processes and composite constituents that are impacting measurement leads to better design of coatings (Occam’s razor-know what is important for the property of interest), separating various degradation processes (chemistry from topography), and detecting changes in the dominant cause of measurement (for example detecting coating crack initiation). Success in understanding and predicting coating’s properties has been achieved with surface degradation in homogenized materials, both using statistical equations and Monte Carlo simulations. Multiphase statistical models, along with the results of Monte Carlo simulations, were developed to predict gloss changes due to environmental weathering. -- Connie Cicha, Secretary, Physics & Astrophysics, connie_cicha@und.nodak.edu, 777-2911