update: forthcoming SISSA MathLab seminars

[Emanuele Tuillier Illingworth]

MATHLAB SEMINARS ANNOUNCEMENT


      Date:

Thursday, 29 October, 2015 - 16:00

*Speaker: *Massimiliano Rossi (University of Munich, Institute of Fluid 
Mechanics and Aerodynamics)

*Room:* SISSA - Santorio A - room 133

*Abstract: *
Measuring the velocity of fluids confined in microscopic devices is a 
challenging task. The small dimensions involved prevent the use of 
conventional probes such as hot wire anemometers or pitot tubes. A 
microscopic adaptation of the particle-image-velocimetry (PIV) 
technique, namely micro-PIV, has been for the past decades the 
gold-standard in this domain. The limitations of micro-PIV are mainly 
two: It gives a two-dimensional measurement of the velocity field, and 
it suffers for errors in the depth direction in case of large velocity 
gradients.  A way to overcome these problems is to use 
3D-particle-tracking methods. However, a major constraint in this case 
is that multi-camera approaches are often not possible and only one 
optical access, usually through a microscope objective, is allowed. In 
this talk, the basics of micro-PIV and the recent advancements in 
3D-particle-tracking methods for micro-flows based on defocusing will be 
presented and discussed. Furthermore, a couple of applications will be 
shown in which the astigmatic-particle-tracking-velocimetry (APTV) 
technique was used to measure complex three-dimensional flows in 
microfluidic devices with sub-micrometric resolution.


      Date (please note change of date):

Wednesday, 11 November, 2015 - 14:30

*Speaker: *Giancarlo Cicconofri (SISSA - International School for 
Advanced Studies)

*Room:* SISSA - Santorio A - room 133

*Abstract: *
I will present some recent results on the analysis of two swimmer models 
(one actuated externally and the other internally). These models provide 
an example of propulsion at low Reynolds number resulting from the 
periodical beating of a passive elastic filament. Motions produced by 
generic periodic actuations are studied within the regime of small 
compliance of the filament. The analysis shows that variations in the 
velocity of beating can generate different swimming trajectories. Motion 
control through modulations of the actuation velocity will be discussed.