 Hello, my name is Dennis Vihill and I'm the corresponding author of the paper entitled Enhanced Algal Gross Rate in a Taylor Vortex Reactor, which is co-authored by Bocong and Jacqueline Shanks. In this paper, we explore the effects of using a highly organized fluid flow pattern to culture microalgae. More specifically, we carried out experiments to determine the effects of this flow pattern on biomass productivity and light utilization efficiency by using Clorella vulgaris. We found that the presence of Taylor vortices causes significant increases in biomass productivity and that these increases are caused by the flashing light effect rather than by mass transport effects. The flashing light effect is a well-known and important phenomenon impacting the behavior of phototrophic microorganisms. In the simplest of terms, photosynthesis consists of a series of almost instantaneous photic reactions followed by thermochemical reactions that occur on the order of milliseconds. This large separation of timescales between the photic and thermochemical reactions means that the photosynthetic turnover time is controlled by the thermochemical timescale. As a result, in optically dense algal cultures, light utilization efficiency can be improved by periodically exposing microorganisms to a quick burst of radiation and then shuttling them to darker regions of the culture suspension while the thermochemical reactions are proceeding, before once again exposing them to light. Taylor vortex flow would seem to provide an efficient mechanism for producing the flashing light effect in a photobioreactor. In the annual region between two concentric cylinders was one or both cylinders undergoing rotation on its main axis. In our experiment, we used a fixed outer cylinder and rotating inner cylinder. At low rotation rates, the fluid has a single velocity component and undergoes simple circular motion. However, above a critical cylinder rotation speed, a centrifugal instability causes the fluid to self-organize into toroidal flow structures known as Taylor vortices as depicted in this figure. As you can see, the Taylor vortices caused the fluid to move not only in a circular motion around the main axis of the cylinders, but also in a circular motion between the inner and outer cylinders, thereby providing a highly effective mechanism for inducing the flashing light effect by efficiently transporting microorganisms between a brightly lit transparent outer cylinder and darker reactor volume near the inner cylinder. As the inner cylinder rotation rate increases, so does the rate at which fluid is transported between the inner and outer cylinder. Although the idea for using Taylor vortex flow to culture algae has been around for a long time, in fact, it dates back to a paper by Miller and co-workers in 1964, it is only now that it has been demonstrated that the rate of biomass production can be enhanced by using Taylor vortex flow. In this figure, we plot biomass concentration as a function of time for different cylinder rotation speeds. The black curve is data obtained without rotation of the inner cylinder and therefore represents results for an annular bubble column. The other growth curves correspond to increasing inner cylinder speeds as we move from blue to green to red. In all of these cases, the cylinder speed is sufficiently large so that Taylor vortices are present. Clearly, there is a significant enhancement of algal biomass production in the presence of Taylor vortices, and this effect is more pronounced as the inner cylinder speed increases. We discuss in more detail these and other results and we hope that you will read our paper. Thanks for listening.