A small eddy viscosity or mass diffusivity that varies with height has been found to have unexpected effects on the Kelvin-Helmholtz (KH) instability of a stably stratified shear layer near the neutral stability boundary. In particular, varying viscosity can increase the growth rate of the instability in contrast to the...
Thermohaline interleaving is an important mechanism for laterally fluxing salt, heat, and nutrients between oceanic water masses. Interleaving is driven by a release of potential energy resulting from the vastly differing diffusivities of heat and salt in seawater. The flows are composed of stacked intrusions that flux more buoyant and...
Vertical transports of plankton, momentum, heat, and turbulence are modeled. A novel integration of high resolution turbulence and biophysical modeling is used to show the influence of a Kelvin-Helmholtz instability on the vertical migration of simple gyrotactic organisms. A viscous limit on mixing driven by shear turbulence is proposed. Large...
Instability and turbulence in sheared, salt-fingering favorable stratification are studied
using three-dimensional direct numerical simulations (DNS). Salt-fingering favorable
stratification is gravitationally stable, because the unstable vertical gradient of salinity
is stabilized by temperature (warm, salty over cool, fresh water-masses). Salt-fingering
instability can occur at the interface of these different water-masses....
When treating highly infectious diseases, patient compliance with caregiver recommendations is crucial. Many patients who contract Ebola Virus Disease have symptoms including vomiting and severe diarrhea and die from the resulting dehydration if they do not drink enough fluids. Telepresence robots are useful in the context of Ebola treatment for...
This thesis aims to determine the impact that Augmentative and Alternative Communication (AAC) devices have on social interactions, and then improves the AAC user experience through a user focus design process. AAC devices enable people who cannot speak to communicate with others. Unfortunately, they are tedious to use and make...
This dissertation focuses on personal privacy in human-robot interaction, which we call "privacy-sensitive robotics." Our understanding of "privacy" is very broad, including not just information privacy but also physical, psychological, and social privacy. We begin by surveying the scholarly literature on privacy and talking about why it applies to interactions...
Robots have the potential to protect health care workers, provide patient care, and ultimately save lives in infectious disease outbreaks. Nevertheless, infectious disease outbreak scenarios present unique technological and social challenges for robotics. This work explores what robots can and should do in the fight against infectious diseases. We present...
Numerous diseases and injuries can limit a person's ability to perform everyday tasks -- things like getting dressed, bathing, and eating. Anything that requires physical activity can be affected; even simple things like turning on the lights can become difficult or impossible. Until recently, the only way for a person...
Automating pick-and-place operations for large steel castings in a foundry is challenging, particularly from a perception point of view. Accurately estimating the identity and orientation of a given part is an open and complex problem, especially if that part sits in a bin of very similar parts. The problem is...