Star-god : enki/ea and the biblical god as expressions of a common ancient near eastern astral-theological symbol system

Nugent, Tony Ormond Syracuse University 1993 국내박사

(Die)Prae- und Postoperative Psychosoziale Situation bei O-Beinkerrekturosteotomien

Nugent, Wolfgang Hamburg Univ. 1982 국내박사

Art, literature, and politics of identity in the High Roman Empire

Nugent, Mark University of Washington 2010 해외박사(DDOD)

This dissertation explores identity politics at the intersection of art and text in the High Roman Empire (ca. 50--250 C.E.). It examines rhetorical and ideological uses of statuary in the writings of Imperial authors---both Greek and Roman---who are concerned with articulating particular cultural narratives and identities. In exploring such discursive uses of statuary, this study foregrounds the variety and complexity of the cultural scene(s) in the High Empire. To this end, authors representing a range of cultural positionalities and affiliations are included: Julia Balbilla, a poet of Syrian Greek and Roman descent; Lucian, a Syrian Greek; Bithynian Dio Chrysostom; Pausanias of Lydia, the tour-guide to Mainland Greece; Apuleius, a Latin sophist from North Africa; Favorinus, a self-styled Gaul who spoke Greek; and Roman Pliny the Younger. The Introduction, entitled "Scribbling on a Colossus," discusses Julia Balbilla's identification of the Memnon Colossus---an artefact subject to competing cultural claims---as a model for her own bicultural identity. Chapter One, entitled "Figures of Speech: Imitative Portraiture and Genealogies of Greekness in Lucian's Images," examines Lucian's use of art as a figurative device for conceptualizing Greek identities under Rome and for (re)considering the dominant modes of cultural reproduction. Chapter Two, entitled "Where Have All the Real Men Gone? Statuary and Virility in Dio Chrysostom's On Beauty and Pausanias' Description of Greece," explores how Pre-Roman sculpture can serve as a locus for anxieties about the emasculating effects of Roman rule. Chapter Three, entitled "Image Troubles: Statues and Reputations in Apuleius' Florida 16 and Favorinus' Corinthian Oration ," investigates Apuleius and Favorinus' strategic engagement with statuary as a facet of their public self-presentation. Chapter Four, entitled "Amateur vs. Connoisseur: Ecphrasis and Self-Fashioning in Pliny the Younger's Epistles 3.6 and Apuleius' Florida 15," discusses Apuleius and Pliny's use of ecphrasis as an instrument of authorial self-fashioning. This dissertation represents, then, a contribution to the growing body of scholarship on the identity politics of the High Empire. It pursues a number of themes prominent in recent work on this topic---the practice of imitation, constructs of masculinity, and sophistic self-fashioning---but with an eye to the visual.

Mixed company: Genre crossings in Rossetti, Eliot, Schreiner, and Woolf

Nugent, Lynne S The University of Iowa 2010 해외박사(DDOD)

This dissertation analyzes interruptions of realist narrative in the work of four women writers from the mid-nineteenth through mid-twentieth centuries: Christina Rossetti, George Eliot, Olive Schreiner, and Virginia Woolf. I argue that these writers use such interruptions—which take the form of alternate genres such as lyric poetry and the expository essay—to subvert the authority of the third-person novelistic narrator and thus question the dominant structure of the realist novel. By employing these asides, they provide opportunities for first-person and present-tense discourse within a third-person, past-tense narrative, which in turn leads to productive contrasts between subjectivity and objectivity, emotion and thought, public and private spheres, inner and outer lives of characters, and the novel and other genres. These cross-genre interruptions destabilize the overall works in ways that reveal both the contradictions in female characters’ lives and the anxieties surrounding being a female author. The practice also exposes limitations of the novel as a form by raising in the reader an awareness of genre conventions. The result is an anti-realist tendency, inspired and fueled by gender concerns, in the midst of the age of greatest dominance of the realist novel.

Breakdown voltage determination of gaseous and near cryogenic fluids with application to rocket engine ignition

Nugent, Nicholas Jeremy Purdue University 2009 해외박사(DDOD)

Liquid rocket engines extensively use spark-initiated torch igniters for ignition. As the focus shifts to longer missions that require multiple starts of the main engines, there exists a need to solve the significant problems associated with using spark-initiated devices. Improving the fundamental understanding of predicting the required breakdown voltage in rocket environments along with reducing electrical noise is necessary to ensure that missions can be completed successfully. To better understand spark ignition systems and add to the fundamental research on spark development in rocket applications, several parameter categories of interest were hypothesized to affect breakdown voltage: (i) fluid, (ii) electrode, and (iii) electrical. The fluid properties varied were pressure, temperature, density and mass flow rate. Electrode materials, insert electrode angle and spark gap distance were the electrode properties varied. Polarity was the electrical property investigated. Testing how breakdown voltage is affected by each parameter was conducted using three different isolated insert electrodes fabricated from copper and nickel. A spark plug commonly used in torch igniters was the other electrode. A continuous output power source connected to a large impedance source and capacitance provided the pulsing potential. Temperature, pressure and high voltage measurements were recorded for the 418 tests that were successfully completed. Nitrogen, being inert and similar to oxygen, a propellant widely used in torch igniters, was used as the fluid for the majority of testing. There were 68 tests completed with oxygen and 45 with helium. A regression of the nitrogen data produced a correction coefficient to Paschen's Law that predicts the breakdown voltage to within 3000 volts, better than 20%, compared to an over prediction on the order of 100,000 volts using Paschen's Law. The correction coefficient is based on the parameters most influencing breakdown voltage: fluid density, spark gap distance, electrode angles, electrode materials and polarity. The research added to the fundamental knowledge of spark development in rocket ignition applications by determining the parameters that most influence breakdown voltage. Some improvements to the research should include better temperature measurements near the spark gap, additional testing with oxygen and testing with fuels of interest such as hydrogen and methane.

Overshooting Convection, Cirrus, and the Cold Point Tropopause in Global Storm-Resolving Models and Satellite Observations

Nugent, Jacqueline M ProQuest Dissertations & Theses University of Wash 2023 해외박사(DDOD)

Processes occurring in upper troposphere-lower stratosphere region (UTLS), especially overshooting convection and radiative heating from thin cirrus, play a key role in the Earth's climate system. The cold point tropopause, defined as the coldest temperature between the upper troposphere and lower stratosphere, is particularly important for determining the moisture content of the lower stratosphere, which feeds back onto the surface warming rate. This work aims to address how the cold point tropopause, overshooting convection, and cirrus are related using five 40-day simulations of global storm-resolving models in addition to 4 years of active and passive satellite observations.We evaluate how convection that overshoots the cold point is distributed across the tropics and find that overshoots only somewhat favor warm land areas over warm ocean regions. The general geographic distribution in cold point overshoots is reproduced by the GSRMs. We also look at radiatively active cirrus near the cold point that are capable of producing a radiative heating rate strong enough to loft and cool the cold point. The GSRMs tend to simulate radiatively active cold point cirrus, as well as thin stratospheric cirrus, much less often than in the observations.Still, despite the differences in the details of how the models simulate cold point overshoots and cirrus, we find consistent relationships between the cold point, overshooting convection, and cirrus in the GSRMs over oceans. Areas with more frequent cold point overshoots were associated with cooler mean cold point temperatures and higher cold point heights. No significant relationship was found between the mean cold points and areas of more frequent radiatively active cold point cirrus, suggesting that this mechanism does not strongly influence the cold point temperature or height. Further work examining longer GSRM simulations is needed to better understand the role of cold point-overshooting convection and cirrus lofting in setting the cold point tropopause in the context of other UTLS processes.

Algorithms for estimating the cluster tree of a density

Nugent, Rebecca University of Washington 2006 해외박사(DDOD)

The goal of clustering is to identify distinct groups in a data set, and assign a group label to each observation. To cast clustering as a statistical problem, we regard the data as an independent and identically distributed sample from some unknown probability density p. We adopt the premise that groups correspond to modes of the density. Our goal then is to find the modes and assign each observation to the "domain of attraction" of a mode. We do this by estimating the cluster tree of the density, a representation of the hierarchical structure of its level sets. Leaves of the cluster tree correspond to modes of the density. An obvious way of estimating the cluster tree of the underlying density p from a sample is to first compute a density estimate pˆ and then use the cluster tree of pˆ as an estimate for the cluster tree of p. We first present an algorithm that computes the cluster tree for piecewise constant density estimates. Exact computation of the cluster tree for general density estimates seems infeasible. Our second contribution is a graph-based approach for approximating the cluster tree of any density estimate. A problem with this graph-based approach is that it requires the edge weights of a graph which are not given in closed form but instead are solutions of an optimization problem; the weight of an edge connecting two observations is the minimum of the estimated density along the edge. Our third contribution is an algorithm that exactly implements the graph-based approach for smooth density estimates.

Growth of carbon microtrees

Nugent, John Michael Rensselaer Polytechnic Institute 2002 해외박사(DDOD)

A chemical vapor deposition process was developed which resulted in the growth of a unique carbon structure that resembles small trees. The trees are grown on a resistively heated graphite electrode where the temperature will reach 1500°C in a matter of seconds. The nucleation of the carbon microtrees is typically assisted by an iron based catalyst. The structure of the carbon microtrees and the physical dimensions of the trees has been determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Deposited onto a carbon nanotube core is a structure that resembles vapor grown carbon fibers. The diameter of the tree increases with increasing distance from the substrate which is a result of the deposition conditions. The atomic structure of the stalk portion of the tree is turbostratic and is classified as rough laminar graphite. At the top of the tree is a cap. There are three different types of cap on the tree that is a function of the length of the tree and ultimately the deposition temperature at that distance. The cap can range from rough laminar pyrocarbon to smooth laminar pyrocarbon to isotropic pyrocarbon. The diameter of the cap is typically much larger than the stalk. The nucleation and growth mechanisms of the carbon microtrees was also investigated. The carbon nanotube core is nucleated and grown using an iron based catalyst particle. The mechanisms of pyrocarbon deposition are strongly affected by temperature. The deposition mechanisms can vary between being driven by gas phase kinetics, where the deposition is driven primarily by physisorption of large graphite molecules, and being driven by surface kinetics, where the deposition mechanism is through chemisorption of ethylene. The different deposition mechanisms result in the differences in microstructure between rough laminar and smooth laminar pyrocarbon. Finite element modelling of the deposition process was performed. It was found that the dominant factor in the deposition of pyrocarbon onto the carbon nanotube core, resulting in the carbon microtree structure, thermal gradient developed from the heating scheme of the substrate.

Hyperactive Alpha2-Chimaerin Reveals the Complexity of Axon Guidance Signaling Pathways in Motor Neuron Development

Nugent, Alicia Anne Harvard University ProQuest Dissertations & Theses 2016 해외박사(DDOD)

alpha2-chimaerin has striking importance for proper neural circuit formation. Individuals with gain-of-function mutations in alpha2-chimaerin have Duane retraction syndrome, a common neurogenic eye movement disorder, and alpha2-chimaerin knockout mice have a rabbit-like hopping gait, resulting from aberrant motor neuron wiring. While molecular mechanisms underlying altered gait circuitry in the loss-of-function mouse have been characterized, mechanisms underlying the etiology of DRS caused by mutant CHN1 remain unclear. Here, we report the first Chn1 gain-of-function DRS mouse model (Chn1KI), which harbors a knock-in point mutation identified in human patients. Chn1WT/KI and Chn1KI/KI embryonic mice exhibit abducens nerve stalling, aberrant trochlear nerve branching, and first cervical spinal segment (C1) misrouting, which result from axon guidance defects. The Chn1KI mouse recapitulates the human DRS phenotype, thus providing a novel mouse model of DRS. Chn1KO/KO embryos display abducens nerve wandering and defasciculation, establishing that human DRS-causing mutations are indeed gain-of-function. We combine detailed 3D whole embryo imaging with novel in vitro approaches to demonstrate that hyperactivated alpha2-chimaerin acts downstream of ephrin forward and reverse signaling selectively in abducens neurons to modulate nerve development, as C1 neurons use only ephrin forward signaling, and trochlear neurons do not significantly use ephrin signaling during nerve guidance. In vivo, we find that selectively removing ephrin forward or reverse signaling via EphA4 dramatically impacts the development of the abducens nerve, distinct from bidirectionally removing EphA4 signaling. Further experimentation reveals that alpha2-chimaerin and EphA4 can signal through other pathways. We find that hyperactivated alpha2-chimaerin modulates BDNF, GDNF, NGF, and HGF signaling in vitro, thus suggesting its role as a broad regulator of axon guidance pathways. Our studies lend insight into the complexity of axon guidance during development and highlight mechanisms that cause the abducens nerve to be selectively vulnerable to alpha2-chimaerin misregulation in DRS.

Solar Radiation and Near-Earth Asteroids: Thermophysical Modeling and New Measurements of the Yarkovsky Effect

Nugent, Carolyn Rosemary University of California, Los Angeles 2013 해외박사(DDOD)

This dissertation examines the influence of solar radiation on near-Earth asteroids (NEAs); it investigates thermal properties and examines changes to orbits caused by the process of anisotropic re-radiation of sunlight called the Yarkovsky effect. For the first portion of this dissertation, we used geometric albedos pV and diameters derived from the Wide-Field Infrared Survey Explorer (WISE), as well as geometric albedos and diameters from the literature, to produce more accurate diurnal Yarkovsky drift predictions for 540 NEAs out of the current sample of ∼8800 known objects. These predictions are intended to assist observers, and should enable future Yarkovsky detections. The second portion of this dissertation introduces a new method for detecting the Yarkovsky drift. We identified and quantified semi-major axis drifts in NEAs by performing orbital fits to optical and radar astrometry of all numbered NEAs. We discuss a subset of 54 NEAs that exhibit some of the most reliable and strongest drift rates. Our selection criteria include a Yarkovsky sensitivity metric that quantifies the detectability of semi-major axis drift in any given data set, a signal-to-noise metric, and orbital coverage requirements. In 42 cases, the observed drifts (∼ 10−3 AU/Myr) agree well with numerical estimates of Yarkovsky drifts. This agreement suggests that the Yarkovsky effect is the dominant non-gravitational process affecting these orbits, and allows us to derive constraints on asteroid physical properties. We define the Yarkovsky efficiency fY as the ratio of the change in orbital energy to incident solar radiation energy, and we find that typical Yarkovsky efficiencies are ∼10−5. The final portion of this dissertation describes the development of and results from a detailed thermal model of potentially hazardous asteroid (29075) 1950 DA. This model combines radar-derived shape models of the object and fourteen 12 micron observations by the WISE spacecraft. The observations were taken at a single phase angle, and this thermophysical model constrains K to less than 0.01 W m−1 K−1. By running Monte Carlo simulations that varied diameter and thermal conductivity over a reasonable range of values, thermal inertia was constrained to be less than 110 J m−2 s−0.5 K−1 . This value is consistent with other measurements of thermal conductivity and inertia for near-Earth asteroids. This dissertation represents a new and original contribution to the study of NEAs. We increased the number of published predicted Yarkovsky drifts by an order of magnitude, increased the number of Yarkovsky detections by a factor of four, and developed new code to derive thermophysical parameters of asteroids that in turn drive their susceptibility to the Yarkovsky drift.