This paper considers the analysis and control of fluid flows using tools from dynamical systems and control theory. The employed tools are derived from the spectral analysis of various linear operators associated with the Navier–Stokes equations. Spectral decomposition of the linearized Navier-Stokes operator, the Koopman operator, the spatial correlation operator and the Hankel operator provid...

We synthesized four novel benzoxazolic and benzimidazolic derivatives of 6-hydroxycoumarin and their photophysical properties were studied. The products with brilliant yellow color shades declared green fluorescence. The emission peaks of the products appeared 456–474 nm. The important characteristic for fluorescent compounds, the Stokes shift νA-νF, oscillator strength f, and fluorescence quan...

This paper seeks to provide clues as to why experimental evidence for the alignment of fibers in semi-dilute suspensions under shear flows does not match theoretical predictions. This paper posits that it is the coupling between Jeffery’s equation and Stokes’ equation that causes the deviation from theory. It is proposed that if the initial data is slightly non-uniform, then there is feedback v...

When a supercooled liquid approaches glass transition, viscous flow slows down greatly, but often the Brownian motion of a molecular probe in the host liquid does not slow down as much, causing the Stokes-Einstein relation to fail by orders of magnitude. Here we formulate a theory that relates the Brownian motion of the probe to two concurrent processes in the host liquid: viscous flow and mole...

We recall the non-Abelian Stokes theorem for the Wilson loop in the Yang –Mills theory and discuss its meaning. Then we move to ‘gravitational Wilson loops’, i.e. to holonomies in curved d = 2, 3, 4 spaces and derive ‘non-Abelian Stokes theorems’ for these quantities as well, which are similar to our formula in the Yang–Mills theory. In particular we derive an elegant formula for the holonomy i...

This paper seeks to provide clues as to why experimental evidence for the alignment of fibers in semi-dilute suspensions under shear flows does not match theoretical predictions. This paper posits that it is the coupling between Jeffery’s equation and Stokes’ equation that causes the deviation from theory. It is proposed that if the initial data is slightly non-uniform, then there is feedback v...