I'm working on a CV for a Mathematical Sciences Ph.D program. Though I don't have any papers published, I have contributed to a number of research groups and given some hour-long presentations. I also did some presentations as part of my capstone projects in both of my undergraduate majors (math and chemistry). I thus think it's valuable to have a "Presentations" section on my CV for now until I have papers published.
However, some of the info in the "Presentations" section would necessarily overlap with some of the info in my "Employment" section, e.g.:
"Developed and presented an improved C algorithm for [analyzing simulations for xxx structure] using [mathematical technique]."
"Presented a literature review on [use of a mathematical technique in simulation] including a detailed overview to the research group on [mathematical algorithm used for analysis]."
How can I distinguish the two sections? Should I emphasize the content of the presentation more in the "presentation" section, and my day-to-day routine more in the "employment" section?
Any other suggestions?