Tribological behaviors of lubricated interfaces are strongly affected by the interactions between mating surfaces and the rheological properties of the lubricant between them. This research aims to improve lubrication through two approaches: 1) designing surface textures for lubrication enhancement and adhesion reduction, and 2) developing lubricants of desired rheology.
Molecular...
The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest...
Amorphous In-Ga-Zn-O (a-IGZO) and other amorphous oxide semiconductors are attracting increasing attention from the display industry for their high electron mobility, ease of large-area manufacture, and potential for future flexible electronics. However, such amorphous materials often show instability under gate voltage bias, temperature, and illumination stress, with extremely slow relaxation...
Mixing of granular materials is an important engineering process, and a very complex problem. In this thesis, I use granular mixing in a half-full biaxial spherical tumbler (BST), a spherical container that rotates sequentially about two orthogonal axes, to motivate the study of mixing with piecewise isometries (PWIs), a rich...
We argue that a country’s level of wealth inequality can be viewed as a reflection of the quality of its housing rental market. Using the ECB’s Household Finance and Consump- tion Survey (HFCS), we document that the aggregate homeownership rate and various measures of wealth inequality are negatively correlated across...
Lattice models of fermions, bosons, and spins have long served to elucidate the essential physics of quantum phase transitions in a variety of systems. Generalizing such models to incorporate driving and dissipation has opened new vistas to investigate nonequilibrium phenomena and dissipative phase transitions in interacting many-body systems. Circuit- QED...
The properties of crystalline materials are controlled by their composition and by their structure, however, the structure of a crystal is only partly controlled by its composition. Development of specifically directed inorganic syntheses will require an understanding of the dynamics of crystal phase forming processes, especially those processes involved in...
This dissertation presents some development of the single molecular ion precision spectroscopy experiment including construction of the project, spectroscopy state readout, and production of ultracold molecules. Such molecular ion spectroscopy aims at testing fundamental physics such as probing the time variation of electron-proton mass ratio.
The theories and characterization of...
I present research in systems of biomedical relevance consisting of agents near or com- prising surfaces using computational approaches. The research topics include formation of bacterial biofilms, behavior of charged species near stacked, like-charged lamellae, and the the conformational behavior of lamellae with strong self-attraction.
In chapter 2, I present...
When we speak, we communicate not only with the words we choose, but also with the patterns of sound we create. As auditory experts, musicians are especially adept at making sense of sound, and accumulating research reveals that this extends to their processing of speech and other communication signals. Much...