Articles by Shima Parsa in JoVE
Other articles by Shima Parsa on PubMed
Freshmen Versus Interns' Specialty Interests Archives of Iranian Medicine. Nov, 2010 | Pubmed ID: 21039007 The purpose of this study was to determine career preferences of medical students at the time of entering medical school compared with interns who were graduating; and to determine what factors influence the choice of a special discipline as a career.
Rotation Rate of Rods in Turbulent Fluid Flow Physical Review Letters. Sep, 2012 | Pubmed ID: 23030093 The rotational dynamics of anisotropic particles advected in a turbulent fluid flow are important in many industrial and natural settings. Particle rotations are controlled by small scale properties of turbulence that are nearly universal, and so provide a rich system where experiments can be directly compared with theory and simulations. Here we report the first three-dimensional experimental measurements of the orientation dynamics of rodlike particles as they are advected in a turbulent fluid flow. We also present numerical simulations that show good agreement with the experiments and allow extension to a wide range of particle shapes. Anisotropic tracer particles preferentially sample the flow since their orientations become correlated with the velocity gradient tensor. The rotation rate is heavily influenced by this preferential alignment, and the alignment depends strongly on particle shape.
Inertial Range Scaling in Rotations of Long Rods in Turbulence Physical Review Letters. Jan, 2014 | Pubmed ID: 24484019 We derive a scaling relationship for the mean square rotation rate of rods with lengths in the inertial range in turbulence: ∝ l(-4/3). We present experimental measurements of the rotational statistics of neutrally buoyant rods with lengths 2.8
Measurement of Flow Velocity and Inference of Liquid Viscosity in a Microfluidic Channel by Fluorescence Photobleaching Langmuir : the ACS Journal of Surfaces and Colloids. Apr, 2014 | Pubmed ID: 24730625 We present a simple, noninvasive method for simultaneous measurement of flow velocity and inference of liquid viscosity in a microfluidic channel. We track the dynamics of a sharp front of photobleached fluorescent dye using a confocal microscope and measure the intensity at a single point downstream of the initial front position. We fit an exact solution of the advection diffusion equation to the fluorescence intensity recovery curve to determine the average flow velocity and the diffusion coefficient of the tracer dye. The dye diffusivity is correlated to solute concentration to infer rheological properties of the liquid. This technique provides a simple method for simultaneous elucidation of flow velocity and liquid viscosity in microchannels.