• Losing Ground: An Ethnography Of Vulnerability And Climate Change In Shishmaref, Alaska

      Marino, Elizabeth K.; Schweitzer, Peter (2012)
      This dissertation presents an ethnography of vulnerability in Shishmaref, Alaska. The village of Shishmaref, population 563, faces imminent threat from increasing erosion and flooding events -- linked to climatic changes and ecological shift -- making the relocation of residents off of the island necessary in the foreseeable future. In spite of ongoing conversations with government agencies since 1974, an organized relocation has yet to occur in Shishmaref. While ecological shift and anthropogenic climate change are no doubt occurring in and around the island, the literature on vulnerability and disaster predicts that social systems contribute at least as much as ecological circumstances to disaster scenarios. This research tests this theory and asks the question: what exactly is causing vulnerability in Shishmaref, Alaska? The resulting dissertation is an exploration of the ecological, historical, social and cultural influences that contribute to vulnerability and risk in Shishmaref. Unlike common representations of climate change and disaster that present the natural environment as a sole driver of risk, this research finds complex systems of decision-making, ideologies of development, and cultural assumptions about social life contribute to why Shishmaref residents are exposed to erosion and flooding and why government intervention and planning remains difficult.
    • Low frequency shelf current fluctuations in the Gulf of Alaska

      Worley, Steven James (1977-08)
      A general oceanographic study of a shelf region in the Gulf of Alaska has revealed low-frequency, current fluctuations. A current meter mooring was located approximately 20 km offshore, in a water depth of 100 m. The time dependent flow is found to be baroclinic and semi-periodic. The effects of local bottom topography, nearshore dilution by river discharge, orographic coastal features, and an island barrier are important to the shelf circulation in this region. The movement of a boundary associated with the Copper River appears to be an important process in controlling the water motion at the mooring site.
    • Low salinity water alternate gas injection process for Alaskan viscous oil EOR

      Saxena, Kushagra; Ahmadi, Mohabbat; Patil, Shirish; Dandekar, Abhijit; Brugman, Robert; Zhang, Yin (2017-05)
      Carbon dioxide has excellent oil swelling and viscosity reducing characteristics. CO₂ injection alternated with water has shown substantial incremental recovery over waterflood for the Alaska North Slope (ANS) viscous oil reservoirs. However, for any project, the ultimate CO₂ slug size is finite and once the apportioned solvent volume is used up, the reservoir oil rates gradually revert to the low waterflood rates during the later life of a field. Low salinity waterflooding (LSWF) has also shown some promise based on corefloods and single well tracer tests in North Slope light oil reservoirs. However, two challenges impede its implementation as a standalone enhanced oil recovery (EOR) option on the North Slope: 1) slow response; the delay prolonged with increasing oil viscosity and 2) large upfront investments for the processing and transport of source water. This study proposes a hybrid EOR scheme, the low salinity water alternate gas (LSWAG) process, for the viscous fields of the ANS. The process was modeled by coupling geochemical and ion exchange reactions to a CO₂-WAG type pattern model of the Schrader Bluff O sand. The Schrader Bluff reservoir has been classified suitable for low salinity EOR based on its permeability, temperature, clay content, and oil and formation water properties. Oil recovery through wettability alteration was modeled through ion exchange at the clay sites. Multiphase compositional flow simulation was run using numerical dispersion control. LSWAG forecast for 50 years following 36 years of high salinity waterflood recovered 15% OOIP more oil over high salinity waterflood and 4% incremental over high salinity WAG. This translates to an improvement of 58% and 11% over waterflood and conventional WAG respectively. Higher oil rates were observed during later life due to increased oil relative permeability caused by the low salinity mechanism. Furthermore, very low solvent utilization values were seen for LSWAG which can be tied to the higher ultimate oil recovery potential of using low salinity water over conventional waterflood. In summary, LSWAG outperformed LSWF and conventional WAG by synthesizing the oil swelling and viscosity reduction advantages of CO₂ with lower residual oil benefits of LSWF, while overcoming the challenges of the late response of LSWF and low waterflood oil rates during later life in a conventional WAG flood.
    • Low-rank high-volatile matter sub-bituminous coal grinding versus power plant performance

      Malav, Dinesh Kumar; Bandopadhyay, Sukumar; Wilson, Terril (Ted); Ganguli, Rajive (2005-08)
      The objective of this project was to determine if the power plant performance, characterized by megawatt and steam generation, is reduced when particle size distribution (PSD) of pulverized-coal fed into the burners is made slightly coarser. Tests were conducted in two phases at a Golden Valley Electric Association power plant. During the first phase, two tests were conducted at significantly different PSDs. Results indicated that coarser distribution did not hurt plant performance. Later, the second phase was carried out to test the repeatability of the observed combustion behavior as well as to test hypotheses on mill power consumption, emissions and unburned carbon. Unfortunately, the three tests in this phase did not result in statistically different PSD's, precluding any conclusions on the main objective. Therefore, further tests are needed to establish the effect of coarser PSD on power plant performance, emissions, unburned carbon and mill power consumption.
    • Lower Tanana Athabascan verb paradigms

      Urschel, Janna Mercedes (2006-05)
      This thesis presents documentation of verb paradigms in the Minto-Nenana dialect of the Lower Tanana Athabascan language, based on fieldwork with four native speakers of the language. Lower Tanana is a severely endangered language spoken in the Interior region of Alaska. The paradigms document the combinations of five Athabascan verb prefixes: classifier, subject, mode, conjugation, and negation. Introductory material describes the Lower Tanana language and outlines the grammar of Lower Tanana verbs, with reference to properties of verbs exemplified in the paradigms. These introductory sections are addressed to teachers and learners of the Lower Tanana language, that they might make optimal use of this thesis as a reference tool in language revitalization efforts.
    • Lower Tanana flashcards

      Dougherty, Summer; Holton, Gary; Ehrlander, Mary E.; McCartney, Leslie (2019-05)
      As part of a study of Lower Tanana, I found it expedient to create a learning tool to help myself gain familiarity with Lower Tanana. I chose to employ Anki, an open-source tool for creating digital flashcard based learning tools. With Anki, I created cards for individual Lower Tanana words and phrases. In producing the computer flashcards for Lower Tanana, I realized that they could serve as a highly flexible system for both preserving and learning Lower Tanana. Further, because of the built-in system flexibility, such systems can be created to aid in preserving and teaching other endangered languages.
    • Lung breathing in the bullfrog: generating respiratory rhythm and pattern

      Davies, Brittany L. (2008-08)
      This research investigated location of the lung respiratory rhythm generator (RRG) in the bullfrog brainstem using neurokinin-1 (NK1R) and [mu]opioid ([mu]OR) receptor colocalization and characterized the role of these receptors in breathing pattern formation. colocalization was distinct near the facial nucleus in juvenile bullfrogs but not in tadpoles. NK1R intensity exhibited no developmental change, while [mu]OR intensity increased from late-stage tadpoles to juvenile frogs. Substance P (NK1R agonist; bath applied) increased lung burst frequency, lung burst cycle frequency (BCF), episode frequency, lung burst amplitude and area, but decreased number of lung bursts per episode and lung burst duration. Antagonist D decreased lung burst frequency and BCF, episode frequency, and the number of lung bursts per episode, and increased lung burst duration and area. DAMGO ([mu]OR agonist; bath applied) decreased lung burst frequency and BCF, episode frequency, and number of lung bursts per episode, but increased all lung burst parameters. Naloxone ([mu]OR antagonist) increased lung burst frequency and BCF, episode frequency, lung bursts per episode but decreased all lung burst parameters. Together these results indicate that NK1R and [mu]OR colocalization represents the lung RRG, and that episode formation is intrinsic to the respiratory control network but may or may not originate in the RRG.
    • Lynx And Coyote Diet And Habitat Relationships During A Low Hare Population On The Kenai Peninsula, Alaska

      Staples, Winthrop R., Iii; Dean, Frederick C. (1995)
      Food habits and habitat use of lynx and coyote were compared 1987-1991 on the Kenai Peninsula, Alaska when the snowshoe hare population was low ($<$0.5 hares/ha). During snow seasons, lynx fed primarily on hares (64% total items), whereas coyotes relied heavily on moose carcasses (42% total items). Diet overlap was 42% and hare use overlap was 16%. Habitat use overlap was 92%, but coyotes used roads more than lynx. Both carnivores selected 1947 burn and avoided 1969 burn and large expanses of mature forest. I conclude that there was exploitation competition for food between these predators, because both used the same habitats and hares, a major food, were scarce. The coyote, however, may be using resources that were previously used by red fox, which have been reduced to low levels. Lynx displayed little fear of humans and were vulnerable to shooting incidental to hunting and depredation events. <p>
    • M.D. Snodgrass: The Founder Of The Alaska State Fair

      Colberg, Talis James (2008)
      This dissertation presents the life of M.D. Snodgrass as an example of how the Alaskan frontier transformed an unremarkable middle aged migrant into a socially prominent civic leader. The life of M.D. Snodgrass exemplifies how American frontier society provides ordinary people with exceptional opportunities to flourish and prosper. One of the end results of Snodgrass's taking advantage of Alaskan frontier opportunity was the Alaska State Fair. The dissertation divides the life of Snodgrass into four phases with the following findings: (1) The first thirty-one years of Snodgrass's life was spent outside of Alaska. His early life in Kansas demonstrates: the forces which formed Snodgrass, the absence of noteworthy activities and the habits he embraced that would remain constant in his long life. (2) The second thesis section documents: how upon arrival in Alaska he was immediately confronted with challenges and opportunities in the wilderness that built his self-confidence, and how he devoted most of the last six decades of his life to advancement of agriculture in Alaska. (3) The third part addresses his political career, with the following observations: the unsettled frontier society had no established upper class and he became socially mobile; being present at the creation of a political system allowed him to attain extraordinary prominence rapidly; and he learned to take risks, to lose and yet keep trying. (4) The final phase demonstrates that by definition a frontier society lacks institutions, and Snodgrass seized the opportunity to be a participant in the creation of two colleges and became the founding figure of the Alaska State Fair. The author concludes that had M.D. Snodgrass never left Kansas he probably would never have been a representative, senator, college trustee, founder of experiment stations, state presidential elector, or the founder of a state fair. A normal individual can accomplish exceptional feats in a frontier setting where the open environment encourages the development of human potential.
    • Mafic -Silicic Magma Interactions From Volcanic To Plutonic: Implications For The Evolution And Eruption Of Silicic Magma Chambers

      Chertkoff, Darren Grant; Eichelberger, John C. (2002)
      In order to investigate the role that mafic-silicic magma interactions play in the origin, evolution, and eruption of shallow crustal magma chambers, a three-part study was undertaken of both effusive (Mt. Dutton volcano, Alaska) and explosive (Volcan Ceboruco, Mexico) eruptions, as well as associated volcanic (Unalaska Formation) and plutonic (Captain's Bay pluton) suites. Major- and trace-element variations suggest that the eruptive products (both andesite and dacite) of Mt. Dutton are not simply a result of fractional crystallization, but instead are affected to varying degrees by two-component mixing of distinct and separate magmas. In this case, petrologic and geochemical evidence, as well as eruptive stratigraphy, suggests the evolution of shallow, silicic magmatic systems inferred to exist beneath small stratovolcanoes can be modeled as resulting from repeated intrusion of mantle-derived mafic magmas into shallow, silicic, crystal-rich, crustal magma chambers. Volcan Ceboruco, Mexico, erupted ~1000 years ago, producing the Jala Pumice and forming a ~4 km wide caldera. During that eruption, 2.8 to 3.5 km3 of rhyodacite magma and 0.2 to 0.5 km 3 of mixed dacite magma were tapped and deposited as the Jala Pumice. Subsequently, the caldera was partially filled by extrusion of the Dos Equis Dome, a low-silica dacite dome with a volume of ~1.3 km3. In this case, petrographic evidence indicates that the Jala and Dos Equis dacites originated largely through the mixing of three end-member magmas: (1) rhyodacite magma, (2) dacite magma, and (3) mafic magma. Study of the Captain's Bay pluton and Unalaska Formation volcanics from Unalaska Island, Alaska, indicates that whole-rock compositions between the two suites span a similar range and particular plutonic units correspond chemically to specific volcanic products. Plagioclase phenocrysts from these chemically similar units also display comparable textures and compositional zoning patterns. Most strikingly, magmatic enclaves found within the pluton show a chemical affinity to andesite lavas from the volcanic suite. In this case, mixing of melts and extrusion of hybrid lava may be a prompt response to recharge, whereas the enclaves may represent "leftovers" that thermally equilibrated with the reservoir as a whole.
    • Magmas In Motion: Degassing In Volcanic Conduits And Fabrics Of Pyroclastic Density Current

      Burgisser, Alain; Eichelberger, John (2003)
      Volcanoes are caused by the transport of magma batches from the Earth's crust to the surface. These magmas in motion undergo drastic changes of rheologic properties during their journey to the surface and this work explores how these changes affect volcanic eruptions. The first part of this study is devoted to the dynamic aspects of degassing and permeability in magmas with high pressure, high temperature experiments on natural volcanic rocks. Degassing is measured by the influence of decompression rate on the growth of the bubbles present in the magma while permeability is deduced from the temporal evolution of these bubbles. The parameterization of our results in a numerical model of volcanic conduit flow show that previous models based on equilibrium degassing overestimate the acceleration and the decompression rate of the magma. Assessing permeability effects derived form our results show that the transition between explosive and effusive eruptions is a strong function of the magma initial ascent rate. The second part of this work is a unification of two end-members of pyroclastic currents (highly concentrated pyroclastic flows and dilute, turbulent pyroclastic surges) using theoretical scaling arguments based on multiphase physics. Starting from the dynamics of the particle interactions with a fundamental eddy, we consider the full spectrum of eddies generated within a turbulent current. We demonstrate that the presence of particles with various sizes induces a density stratification of the current, leading to its segregation into a basal concentrated part overlain by a dilute cloud. To verify our predictions on the interactions of such a segregated pyroclastic current with its surroundings (hills and sea), we studied the products of the 2050 BP caldera-forming eruption of Okmok Volcano (Alaska). This field study allowed us to reconstruct the eruptive sequence and to validate the main aspects of our theoretical model, such as the superposition of a dense and dilute part, their decoupling at sea entrance and the characteristics of the particles they transport.
    • Magnetic Reconnection As A Chondrule Heating Mechanism

      Lazerson, Samuel A.; Wiechen, Heinz (2010)
      The origin of chondrules (sub-millimeter inclusions found in stony meteorites) remains today an open question despite over century of examination. The age of these proto-solar relics shows a well defined cutoff of around 4.5 billion years ago. This places them as the oldest solids in the solar system. Chemical examination indicates that they experienced heating events on the order of 5000 K/hr for periods of around 30 minutes, followed by extending periods of cooling. Additional examination indicates the presence of large magnetic fields during their formation. Most attempts to explain chondrule formation in the proto-solar nebula neglect the existence of a plasma environment, with even less mention of dust being a charge carrier (dusty plasma). Simulations of magnetic reconnection in a dusty plasma are forwarded as a mechanism for chondrule formation in the proto-solar nebula. Here large dust-neutral relative velocities are found in the reconnection region. These flows are associated with the dynamics of reconnection. The high Knudsen number of the dust particles allows for a direct calculation of frictional heating due to collisions with neutrals (allowing for the neglect of boundary layer formation around the particle). Test particle simulations produce heating equivalent to that recorded in the chondrule mineral record. It is shown that magnetic reconnection in a dusty plasma is of fundamental importance to the formation of the most primitive solids in the solar system.
    • Magnetic reconnection in the presence of sheared plasma flow

      La Belle-Hamer, Annette Louise; Lee, L. C. (1994)
      Classical models of magnetic reconnection consist of a small diffusion region bounded by two slow shocks, across which the plasma is accelerated. Most space plasma current sheets separate two different plasmas, violating symmetry conditions across the current sheet. One form of asymmetry is a sheared plasma flow. In this thesis, I investigate the magnetic reconnection process in the presence of a shear flow across the current sheet using two-dimensional magnetohydrodynamic (MHD) simulations. The results show that only for sheared flow below the average Alfven velocity of the inflow regions can steady state magnetic reconnection occur. A detailed examination of the Rankine-Hugoniot jump conditions reveals that the two slow shocks of earlier models are replaced by a strong intermediate shock and a weaker slow shock in the presence of shear flow. Both symmetric and asymmetric density profiles are examined. Depending upon the direction of the flow in the adjacent inflow region, the effects from the sheared flow and the effects from the density asymmetry will compete with or enhance each other. The results are applied to the dayside and flank regions of the magnetosphere. For tailward flow in the flanks, the two asymmetries compete making the magnetic field transition layer broad with the high speed flow contained within the transition region. For the dayside region, the magnetic field transition region is thin and the accelerated flow is earthward of the sharp current layer (magnetopause). These results are consistent with the data. A velocity shear in the invariant direction was examined under otherwise symmetric conditions. With the magnetic field initially only in the $x-y$ plane, $B\sb{z},$ and consequently field-aligned current, is generated by the initial $v\sb{z}.$ The field-aligned current depends on the velocity profiles in all directions. For a velocity sheared in both the z and the y direction, the results show a very localized region of large field-aligned currents.
    • Magnetohydrodynamic Simulations Of Plasma Dynamics In The Magnetospheric Cusp Region

      Adamson, Eric T.; Otto, Antonius (2012)
      The Earth's magnetospheric cusp regions are rich in interesting plasma physics. The geomagnetic cusps offer solar wind plasma a relatively easy entry point into the magnetosphere through magnetic reconnection with the interplanetary magnetic field. The cusp regions are characterized by various interesting and important observations such as low energy particle precipitation, significant outflow of ionospheric material, and the frequent presence of energetic particles in regions of depressed magnetic field strength. The physical mechanisms that lead to these observations is often unresolved, for instance the acceleration mechanism for energetic cusp populations is not understood, nor is it known what implications they may have on magnetospheric dynamics. It is however, well accepted that magnetic reconnection plays a critical role in the vicinity of the cusps and is likely responsible for much of the dynamics in the region. Modeling of the geomagnetic cusps is notoriously challenging. Global magnetospheric models have proven indispensable in the study of the interaction of the solar wind plasma with the Earth's magnetosphere, however, the exterior cusp region poses a significant challenge for these models due to their relatively small scale. I have developed a mesoscale cusp-like magnetic field model in order to provide a better resolution (up to 300 km) of the entire cusp region than is possible in these global models. Typical observational features of the high-altitude cusps are well reproduced by the simulation. Results for both strongly northward and strongly southward interplanetary magnetic field indicate extended regions of depressed magnetic field and strongly enhanced plasma beta (cusp diamagnetic cavities). The Alfvenic nature of the outer boundary between the cusp and magnetosheath, in addition to the flow characteristics in the region, indicate that magnetic reconnection plays an important role in structuring the high-altitude cusp region. The inner boundaries with magnetosphere are gradual transitions forming a clear funnel. These cavities further present a unique configuration in which reconnecting magnetic flux tubes may gain a significant amount of flux tube entropy (H = p1/gammaV) through topological changes due to magnetic reconnection.
    • Magnetospheric imaging of EUV emissions at 83.4 and 30.4 nm wavelengths

      Garrido, Dante Espino; Smith, R. W. (1994)
      Magnetospheric images are constructed from resonant scattering of emissions by He$\sp+$ 30.4-nm and O$\sp+$ 83.4-nm ions from different spatial locations to study the structure of the intensities and its relation to the distribution of He$\sp+$ and O$\sp+$ ions around the Earth. The image intensities at these EUV wavelengths were obtained from a knowledge of ion scattering rates and available data on ion densities. This particular approach is called forward modelling and consists of the calculation of simulated EUV images of the magnetosphere. Different regions in the magnetosphere have been considered in this study to determine the dependence of the image intensities on ion energies and ion drift speeds with respect to the Sun-Earth line. Hot O$\sp+$ ions in the energy range from 1 keV to 50 keV are present in the plasma sheet with typical densities of the order of 0.1 ions cm$\sp{-3}$ arising during disturbed times. Image intensities of the order of a few millirayleighs were obtained in our simulations for these densities. During quiet times the densities are of the order of 0.05 ions cm$\sp{-3}.$ The reduction of the image intensities as a result of Doppler shifts caused by ion motion relative to the Sun-Earth line is discussed in detail and the effects of ion dynamics (particle acceleration) in the polar cap on the image intensities have also been analyzed for both He$\sp+$ and O$\sp+$ ions. The possibility of detecting polar outflows may also depend on the location of the imager. Simulated images of the plasmasphere and trough regions in both 30.4-nm and 83.4-nm wavelengths have been obtained to reflect the relative abundance of the ions in these regions. Photometric intensities of He$\sp+$ at 30.4 nm were obtained from a spinning rocket at an altitude of 435 km. The different viewing angles covered a wide range of regions in the magnetosphere, and this particular rocket geometry offered the possibility of obtaining the He$\sp+$ ion distribution from the measured intensities. This method (forward inversion) can be applied to 2-D images and it is shown that it is possible to extract 3-D ion distributions from the images.
    • Magnus' expansion as an approximation tool for ordinary differential equations

      Carlson, Tim (2005-05)
      Magnus' expansion approximates the solution of a linear, nonconstant-coefficient system of ordinary differential equations (ODEs) as the exponential of an infinite series of integrals of commutators of the matrix-valued coefficient function. It generalizes a standard technique for solving first-order, scalar, linear ODEs. However, much about the convergence of Magnus' expansion and its efficient computation is not known. This thesis describes in detail the derivation of Magnus' expansion and reviews Iserles' ordering for efficient calculation. Convergence of the expansion is explored and known convergence estimates are applied. Finally, Magnus' expansion is applied to several numerical examples, keeping track of convergence as it depends on parameters. These examples demonstrate the failure of current convergence estimates to correctly account for the degree of commutativity of the matrix-valued coefficient function.
    • The maiden's firestorm

      Aruffo, Heather; Soos, Frank; Johnson, Sara Eliza; Carr, Rich (2019-05)
      The Maiden's Firestorm is a work of speculative fiction set in the fictional Solonian Worker's Republic, a country reminiscent of the Soviet Union in the 1940s. Geopolitically, the novel centers around the conflict between the Solonian Worker's Republic and the nomadic Kyzare, an ethnic group with terrifying telepathic abilities caused by an element called Yinitrium. The story is told through the point of view of two adult children of a mixed race Kyzare-Solonian family, who must navigate the consequences of their marginalized identities in a hostile world. The first point of view follows Rakell, an engineering student who is recruited to work on a top secret weapons project, and is given the choice between Party membership and denouncing her mother, a former Worker's Party member. The second point of view follows Rakell's older brother Yeordan, who is forced by the Solonian state to spy on their estranged father, a Kyzare nationalist in charge of the Mind Warriors. The stories are interwoven throughout the novel, and are used to develop themes of political and familial loyalty, as well as nationalism, and the role of personal relationships under extenuating circumstances. The novel uses speculative fiction to address real world historical and political questions. The relationship between the Kyzare's telepathic abilities and Yinitrium allows the speculative elements to function as metaphor, and mirrors Solonian attempts to weaponize Yinitrium. In this way, power is explored as a theme, as both groups use the element to exert control over the continent.