Northern California Section
The Drive to More Efficient Lubricants
Wednesday, June 25, 2014 Noon to 2 p.m.
Spenger’s Fresh Fish Grotto, Berkeley
RSVP By: Monday March 24
Presenter: Uma Ramasamy and Hongyu Gao, UC Merced
Abstract & Bios
Uma Ramasamy has been working in the UC Merced tribology group under direction of Professor Ashlie Martini pursuing a PhD in Biological Engineering and Small Scale Technology. She received a BS in Chemical Engineering from Purdue University. In addition to presenting at the last two national STLE meetings, Uma served as a student poster coordinator at the STLE 69th annual meeting and exhibition at Lake Buena Vista FL.
Uma will present her research on estimating pressure-viscosity coefficients (PVC) using molecular dynamics (MD) simulations as an alternative to the traditional approach requiring extensive measurements. This method uses an empirical expression based on Doolittle Free-Volume Theory that relates compressibility to PVC, where compressibility is estimated from MD simulations of nanoscale volumes of fluid. The proposed method is tested for two molecules, polyalphaolefin and di-2(ethylhexyl) sebacate, and compared to experimental PVC reports. They anticipate that this approach will ultimately provide a fundamental understanding of the effect of molecular structure on PVC.
Hongyu (Larry) Gao joined the ME program at UC Merced in August 2011 and is pursuing a PhD in Mechanical Engineering and Applied Mechanics. Prior to attending UC Merced, Larry has previous attended graduate and undergraduate studies at Beijing University of Chemical Technology and Stevens Institute of Technology. Larry is the first author and co-author of numerous papers in peer-reviewed journals.
Larry’s research presentation is on the load dependence of silver tantalate (AgTaO3) as a high-temperature solid lubricant. Experiments and molecular dynamics simulations of sliding contact of AgTaO3 predict that friction increases with normal load and decreases with temperature. Analysis of the composition of the tribofilm indicates that Ag atoms are easily displaced from the contact and aggregate outside the wear track, and that this silver redistribution is more significant at higher loads. The findings suggest possible sliding mechanisms for AgTaO3, in which both the segregation of silver and tribofilm density play important roles.
REVISED MENU POLICY: We will order from our STLE lunch menu. Spenger’s will take your order when you are seated. We will be able to eat earlier and finish lunch in time for the presentation.
Please send RSVP to firstname.lastname@example.org by June 23 to reserve a seat.
COST: Members and Guests - $30.00 Cash or Check at the door
RSVP to: email@example.com
LUNCH: 12:00 p.m.
PRESENTATION: 1:00 p.m. (no charge, but RSVP to reserve a seat)
Spenger’s Fresh Fish Grotto
1919 Fourth St.
Thank you… please pass this note on to anybody that would like to attend, need not be a member to attend.
YOUR 2013-2014 NORCAL STLE Committee
Greg Croce – Chair
Rob Mills – Vice Chair
Paula Vettel – Secretary
Jack Zakarian – Treasurer
Ehren Herguth – Program Chair