Engineering Commons^™

Oxidative Aging And Fracture Behavior Of Polymers And Composites: Theory, Modeling And Experiments, Shabnam Konica

Dissertations, Master's Theses and Master's Reports

Polymers and their composites (PMC) have emerged as effective alternative materials in structural, aerospace, and automotive industries due to their lightweight and tunable properties compared to metals. However, these materials tend to degrade during their operations in extreme environments. In this work, two extreme conditions are considered: - i) high-temperature oxidative degradation of polymers and polymer-based composites ii) Fracture and damage of polymer-based composites under thermo-mechanical loading.

Polymer oxidation starts when oxygen from the ambient diffuses into the bulk material and initiates chemical reactions to develop a coarse, brittle oxide layer on the exposed surface. The oxidative degradation process is …

Design And Implementation Of An Oxidation Catalyst For A Spark Ignited Two Stroke Snowmobile Engine, Noah Squires

Dissertations, Master's Theses and Master's Reports

Spark ignited two stroke engines are under increasing pressure as emissions standards become stricter, making them a perfect candidate for a catalytic aftertreatment system. Yet several significant challenges to catalysis exist. Namely two stroke exhaust systems are very sensitive to back pressure changes and high emissions concentrations can make controlling the temperature of the catalytic reaction difficult. Therefore, it is imperative that a two stroke specific catalyst design process be developed. This project focused on beginning to develop such a design process. Key results of this work include finding a location for the catalyst in the exhaust system that offers …