Shared interest in heavy-ion (HI) collisions has driven our joint research projects with Betty Tsang. These projects have spanned different methods of HI-data analysis, using transport theory to interpret HI data and inference of nuclear-matter properties. The projects discussed in detail will include a study of isospin diffusion. Betty has strongly impacted the practicalities of HI transport theory by instigating the Transport Model Evaluation Project, which aims to narrow uncertainties in the conclusions drawn from the models.