In this thesis we develop a theory of Fourier analysis and fast Fourier transforms (FFTs) for finite inverse semigroups. Our results generalize results in the theory of Fourier analysis for finite groups. There is a general method for generating...
Three-dimensional imaging in medicine -- Mathematical models. ; Stereoencephalotomy.
In the past, clinicians skilled at image-guided neurosurgery have relied solely on pre-operative scans for their navigational information. Often in the course of surgery, tissue is purposely retracted/resected or inadvertently moved resulting in a...
This research has established feasibility of surface temperature characterization using ruby fluorescence. Study was performed in pin-on-disk geometry, with balls made of different plastics sliding against the sapphire disk. Fluorescence signal was...
Three-dimensional imaging in medicine -- Mathematical models. Diagnostic imaging -- Digital techniques. Brain -- Magnetic resonance imaging. Inverse problems (Differential equations).
An accurate registration between the preoperative images and the current surgical scene is critical to image-guided neurosurgery. However, during a neuro-surgical intervention, brain tissues shift and degrade the accuracy of the registration....
Magnetic Resonance Elastography (MRE) has emerged as a noninvasive, quantitative physical examination of the elastic properties of soft biological tissues including breast, liver, prostate, and brain. Implementation of constitutive relations that...
Microelectronics -- Design and construction. ; Micromachining. ; Strains and stresses. ; Silicon compounds.
This dissertation presents the use and extension of capabilities of surface machining technology, utilizing stress engineering between polysilicon and silicon nitride layers to build three-dimensional microstructures. A new theory and experimental...
Continual improvements to clinical breast imaging technologies have led to ever earlier detections and increasingly accurate localizations of female breast cancers. While these advancements have certainly improved the prognoses of many patients,...
Ultra-high molecular weight polyethylene (UHMWPE) remains the most common bearing material for total joint arthroplasty. Advances in radiation cross-linking and other post-consolidation treatments have led to a rapid differentiation of polyethylene...
This project focuses on the development of research tools and methods that are used to study the relationship between neural activity and subsequent hemodynamic responses in the human brain. This relationship, referred to as neurovascular coupling,...
Casimir effect. Zero-point field. Electric conductivity. Quantum electrodynamics.
The Casimir force arises from an alteration of boundary condition in vacuum and is often regarded as a manifestation of quantum zero point energy. Considerable progress has been made in the last decade with an impressive achievement of experimental...
Ice mechanics. Compressibility. Fracture mechanics. Strains and stresses. Brittleness.
This work describes the effect of triaxial compressive confinement on the strength of columnar S2 ice loaded under conditions leading to brittle failure. Cubes of columnar S2 ice were tested at -10 °C under triaxial (proportional) loading where...
Breast -- Cancer -- Tomography. ; Breast -- Cancer -- Imaging. ; Microwave imaging in medicine. ; Breast -- Electric properties. ; Breast Neoplasms -- diagnosis. ; Diagnostic Imaging -- methods.
This thesis centers around a generalization of the classical discrete Fourier transform. We first present a general diagrammatic approach to the construction of efficient algorithms for computing the Fourier transform of a function on a finite...
Developmental prosopagnosia (DP) is a neurodevelopmental disorder defined by impaired face recognition in the absence of brain damage, low-level visual deficits, or broad cognitive problems. Behavioral and neural findings suggest different types of...
The thesis is dedicated to the understanding and characterization of brittle compressive fracture of columnar S2 ice. The work quantifies the strength of fresh-water S2 ice and investigates its characteristic brittle failure modes under biaxial...
This thesis presents technologies for the design, fabrication, operation, and control of electrostatic MEMS micro-robots. It describes prototype micro-robots, with dimensions of 60 μm by 250 μm by 10 μm, that are capable of controllable...
Circadian rhythms in a wide variety of cellular and metabolic processes are well documented in many organisms. An important step in understanding the molecular basis of the circadian clock is the characterization of clock-controlled genes. mRNA...
The effects of vacancies on the mechanical properties of FeAl single crystals and polycrystals have been investigated. Scanning calorimetric results indicate that vacancies in quenched Fe-40Al undergo rearrangement at ~550K, and then annihilate at...
Automatic control -- Sensitivity. Structural control (Engineering). Strains and stresses -- Computer simulation. Structural analysis (Engineering). Engineering models.
Autonomous damage detection in engineering structures is critically important as the demands placed upon those structures are increased. It has been well established that damage detection can be done through monitoring the modal frequencies of the...
Structural control (Engineering). ; Smart structures -- Vibration. ; Strains and stresses -- Computer simulation. ; Automatic control -- Sensitivity. ; Feedback control systems.
This thesis investigates vibration-based damage identification problems in smart structures. Vibration-based damage metrics suffer from small sensitivity of modal properties to damage, thus making it difficult to detect, locate, and determine the...
Geology -- Guatemala -- Lake Atitlan area; Volcanism -- Guatemala -- Lake Atitlan area; Calderas -- Guatemala -- Lake Atitlan area.
Geological mapping, petrological and geophysical studies in the lake Atitlan area, Guatemala, have revealed four distinct periods of stratovolcano growth, each followed by major silicic eruptions and caldera collapse. The first period (12 - 11 my...
A method for the reconstruction of a spectrum of mechanical properties from phase-contrast, MR displacement data is developed and implemented via the finite element method. To overcome the significant computational load associated with...
We present designs, theory and the results of fabrication and testing for a novel parallel microrobotic assembly scheme using stress-engineered MEMS microrobots. The robots are 240-280 μm × 60 μm × 7-20 μm in size, each robot consist of a...
Fluorine forms the strongest single bond to carbon, however, it is well established that transition metals can lengthen and weaken C-F bonds in fluorinated ligands. Described here are studies on the activation of C-F bonds in iridium compounds...
Experimental and theoretical aspects of macroscopic and mesoscopic elastic instability are investigated in this thesis. For the theoretical investigations we utilize a Lagrangian formulation of nonlinear continuum elasticity theory, the novel...