This thesis deals with three problems encountered in micro- and nano-fluidics: linear stability analysis of electrokinetic mixing in icrochannels, development of a general purpose numerical technique for fully resolved simulation of electrohydrodynamic particulate flows, and studying the phenomenon of molecular scale slip next to boundaries in micro- and nano-channels.
Mixing...
In this thesis we study protein folding with external force. In Part I we simulate the folding or unfolding procedure based on the two-state model. For constant-velocity experiments, the simulation results fit the experimental results. For constant-force experiments, we introduce cooperativity between domains to explain the different behavior between single...
The need for low-cost robust meso-scale "smart" robots (manipulators) that have no discrete parts (monolithic), no sensors ("self-sensing") and can be used in space-constrained systems, e.g., in microfactories, biomedical applications, etc., was the motivation for the current research. This study describes the design, fabrication and analysis of such a smart...
A comprehension of the complex dynamics of gaseous combustion requires an understanding of the underlying fundamentals. In this dissertation, I examine planar diffusion flames from both an experimental and numerical perspective.
In the first part of this thesis, I study the extinction of unstrained, planar counter-diffusion flames. The theoretical model...
The "Z-width" of a haptic display is the dynamic range of impedances that can be passively rendered. Haptic displays with larger Z-width generally render more realistic feeling virtual environments. The maximum passive impedance a haptic display can render is directly related to the quantity of physical damping in the mechanism,...
The finite element method is used to investigate failure mechanisms in pin-hanger connections in aging highway bridges. Bridge pins and hangers are typically considered as critical elements whose failure may result in partial or entire collapse of the structure. The primary function of a pin-hanger connection is to allow for...
The rat whisker (vibrissal) system provides rats with an exquisitely acute tactile sense that has helped allow them to thrive all over the world. By actively rotating their whiskers back-and-forth ("whisking") against objects, rats can extract a rich variety of information including position, size, shape, orientation and texture. Today, however,...
In the last two decades the number of innovative applications for advanced materials has been rapidly increasing. Shape memory alloys (SMAs) are an exciting class of these materials which exhibit large reversible stresses and strains due to a thermoelastic phase transformation. SMAs have been employed in the biomedical field for...
Novel materials and nanostructures with superior electro-mechanical properties are emerging in the development of novel devices. Engineering application of these materials requires accurate electro-mechanical characterization, which in turn requires development of novel experimental techniques. This dissertation outlines the investigation of the mechanical and electrical properties of one-dimensional nanomaterials.
One-dimensional nanomaterials...
A dynamic model of the rolling process that includes the material strain-hardening and work roll flattening effects was developed based on homogeneous deformation theory. By coupling this new dynamic rolling process model with a structural model for a mill stand, a single-stand chatter model expressed through a state-space representation was...