Metal powders -- Extrusion. Metal powders -- Microstructure. Shear flow.
The manufacture of bulk parts from metastable powder materials requires new approaches to cold consolidation. One potential technique is equal-channel angular extrusion (ECAE), a simple shear process. This thesis describes an investigation into the...
Two alloys, Fe 55 Mn 19 Al 26 and Fe 30 Ni 20 Mn 35 Al 15 , were studied in this research project. The yield stress anomaly (YSA) of Fe 55 Mn 19 Al 26 single crystal was observed with a yield stress peak at 700 K. In situ TEM straining revealed...
In the Firefighter Problem, a fire starts at a vertex of a graph, and in discrete time units, it spreads from burned vertices to their neighbors, unless they are protected by one of the f firefighters that are deployed every turn. Once burned or...
Sorting very large datasets is a key subroutine in almost any application that is built on top of a large database. Two ways to sort out-of-core data dominate the literature: merging-based algorithms and partitioning-based algorithms. Within these...
This thesis presents data from ground camera observations of the aurora conducted from Alaska during the winters of 2005 through 2007. In conjunction with these camera observations, conjugate radar observations of the auroral ionosphere were...
We present new forensic tools that are capable of detecting traces of tampering in digital images without the use of watermarks or specialized hardware. These tools operate under the assumption that images contain natural properties from a variety...
Access control is a core component of any information-security strategy. Researchers have spent tremendous energy over the past forty years defining abstract access-control models and proving various properties about them. However, surprisingly...
Diffuse optical imaging techniques can be combined with standard imaging technologies such as computed tomography (CT) and magnetic resonance (MR) imaging to allow measurement of spectroscopic signals pertaining to the molecular components of...
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...
For ordinary knots in R 3 , there are no degree one Vassiliev invariants. For virtual knots, however, the space of degree one Vassiliev invariants is infinite dimensional. We introduce a sequence of three degree one Vassiliev invariants of virtual...
'The control of waves using periodic structures is crucial for modern optical, electromagnetic and acoustic devices such as diffraction gratings, filters, photonic crystals, solar cells, sensors, and absorbers. We present a high-order accurate...
We start by introducing avoidance coupling of Markov chains, with an overview of existing results. We then introduce and motivate a new notion, uniform coupling. We show that the only Markovian avoidance coupling on a cycle is of this type, and...
Van Allen radiation belts -- Mathematical models. Electrons -- Diffusion -- Mathematical models. Magnetohydrodynamic waves -- Mathematical models.
It is becoming increasingly important to understand the dynamics of radiation belt energetic particles given their potentially hazardous effects on satellites and our ever-increasing dependence on those satellites. There is a need to determine...
Over the past decade, a pair of instructions called load-linked (LL) and store-conditional (SC) have emerged as the most suitable synchronization instructions for the design of lock-free algorithms. However, current architectures do not support...
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...
Niemann-Pick type C (NPC) disease is a fatal autosomal recessive pediatric neurovisceral disorder characterized clinically by progressive neurodegeneration in the central nervous system (CNS) and hepatosplenomegaly. Biochemically, it is...
Most solid tumors are aneuploid, and many tumor cells persistently mis-segregate whole chromosomes at an elevated rate in a process called chromosomal instability (CIN). CIN occurs due to loss of chromosome segregation fidelity during mitosis,...
Manifolds (Mathematics) Geodesics (Mathematics) Space and time.
We investigate weak and strong refocusing of light rays in a space-time and related concepts. A strongly causal space-time ( X^ n +1 , g ) is emphstrongly refocusing at x âˆˆ X if there is a point y â‰ x such that all null-geodesics through y pass...
Optical tomography. Fluorescence. Imaging systems -- Design and construction. Diagnostic imaging -- Mathematical models. Brain -- Diseases -- Diagnosis. Brain -- Magnetic resonance imaging.
Fluorescent molecules targeted to reveal information on tissue function have been used as research tools in ex vivo and subsurface characterization of diseased tissue for years. Exploiting this specificity for in vivo imaging through centimeters of...
Hypervelocity stars are stars ejected from the center of the Milky Way, never to return. Since first discovered in 2005, hypervelocity stars have greatly increased our understanding of the kinematics and dynamics at the Galactic Center. In this...
Football Teams 1950s-Present; 1968; Newspaper article: (NX5) New Haven, Conn., Nov. 4 Off and running -- Brian Dowling, (10), Yale quarterback. setting up first Yale touchdown Saturday with a 16-yard run against Dartmouth. Behind Dowling's passing...
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,...
Magnetic nanoparticle-based hyperthermia for cancer treatment is a promising technology, particularly when applied as part of an adjuvant strategy with established cancer therapies (chemotherapy, radiation and surgery). In Europe, early clinical...
Radio relics are extended regions of synchrotron radio emission that have been found in the outskirts of a few dozen galaxy clusters. Relics are often associated with clusters undergoing merger activity. They are not associated optically with a...
Thermodynamics, and the classic balance between entropy and enthalpy, provides a proverbial zoo of exotic phase behaviour that chemists can harness to create new materials out of simple liquids and polymers. The diversity of self-assembling...
The purpose of this thesis is to describe methods for detecting hidden crevasses on glaciers in Polar regions. Crevasses form in ice sheets as a result of forces imposed upon the brittle ice. The crevasses are hidden from view by bridges of soft...