Matching Items (684)
Filtering by

Clear all filters

151710-Thumbnail Image.png
Description
In this thesis I model the thermal and structural evolution of Kuiper Belt Objects (KBOs) and explore their ability to retain undifferentiated crusts of rock and ice over geologic timescales. Previous calculations by Desch et al. (2009) predicted that initially homogenous KBOs comparable in size to Charon (R ~ 600

In this thesis I model the thermal and structural evolution of Kuiper Belt Objects (KBOs) and explore their ability to retain undifferentiated crusts of rock and ice over geologic timescales. Previous calculations by Desch et al. (2009) predicted that initially homogenous KBOs comparable in size to Charon (R ~ 600 km) have surfaces too cold to permit the separation of rock and ice, and should always retain thick (~ 85 km) crusts, despite the partial differentiation of rock and ice inside the body. The retention of a thermally insulating, undifferentiated crust is favorable to the maintenance of subsurface liquid and potentially cryovolcanism on the KBO surface. A potential objection to these models is that the dense crust of rock and ice overlying an ice mantle represents a gravitationally unstable configuration that should overturn by Rayleigh-Taylor (RT) instabilities. I have calculated the growth rate of RT instabilities at the ice-crust interface, including the effect of rock on the viscosity. I have identified a critical ice viscosity for the instability to grow significantly over the age of the solar system. I have calculated the viscosity as a function of temperature for conditions relevant to marginal instability. I find that RT instabilities on a Charon-sized KBO require temperatures T > 143 K. Including this effect in thermal evolution models of KBOs, I find that the undifferentiated crust on KBOs is thinner than previously calculated, only ~ 50 km. While thinner, this crustal thickness is still significant, representing ~ 25% of the KBO mass, and helps to maintain subsurface liquid throughout most of the KBO's history.
ContributorsRubin, Mark (Author) / Desch, Steven J (Thesis advisor) / Sharp, Thomas (Committee member) / Christensen, Philip R. (Philip Russel) (Committee member) / Arizona State University (Publisher)
Created2013
ContributorsWasbotten, Leia (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-30
152040-Thumbnail Image.png
Description
"Sensor Decade" has been labeled on the first decade of the 21st century. Similar to the revolution of micro-computer in 1980s, sensor R&D; developed rapidly during the past 20 years. Hard workings were mainly made to minimize the size of devices with optimal the performance. Efforts to develop the small

"Sensor Decade" has been labeled on the first decade of the 21st century. Similar to the revolution of micro-computer in 1980s, sensor R&D; developed rapidly during the past 20 years. Hard workings were mainly made to minimize the size of devices with optimal the performance. Efforts to develop the small size devices are mainly concentrated around Micro-electro-mechanical-system (MEMS) technology. MEMS accelerometers are widely published and used in consumer electronics, such as smart phones, gaming consoles, anti-shake camera and vibration detectors. This study represents liquid-state low frequency micro-accelerometer based on molecular electronic transducer (MET), in which inertial mass is not the only but also the conversion of mechanical movement to electric current signal is the main utilization of the ionic liquid. With silicon-based planar micro-fabrication, the device uses a sub-micron liter electrolyte droplet sealed in oil as the sensing body and a MET electrode arrangement which is the anode-cathode-cathode-anode (ACCA) in parallel as the read-out sensing part. In order to sensing the movement of ionic liquid, an imposed electric potential was applied between the anode and the cathode. The electrode reaction, I_3^-+2e^___3I^-, occurs around the cathode which is reverse at the anodes. Obviously, the current magnitude varies with the concentration of ionic liquid, which will be effected by the movement of liquid droplet as the inertial mass. With such structure, the promising performance of the MET device design is to achieve 10.8 V/G (G=9.81 m/s^2) sensitivity at 20 Hz with the bandwidth from 1 Hz to 50 Hz, and a low noise floor of 100 ug/sqrt(Hz) at 20 Hz.
ContributorsLiang, Mengbing (Author) / Yu, Hongyu (Thesis advisor) / Jiang, Hanqing (Committee member) / Kozicki, Micheal (Committee member) / Arizona State University (Publisher)
Created2013
151635-Thumbnail Image.png
Description
Libby Larsen is one of the most performed and acclaimed composers today. She is a spirited, compelling, and sensitive composer whose music enhances the poetry of America's most prominent authors. Notable among her works are song cycles for soprano based on the poetry of female writers, among them novelist and

Libby Larsen is one of the most performed and acclaimed composers today. She is a spirited, compelling, and sensitive composer whose music enhances the poetry of America's most prominent authors. Notable among her works are song cycles for soprano based on the poetry of female writers, among them novelist and poet Willa Cather (1873-1947). Larsen has produced two song cycles on works from Cather's substantial output of fiction: one based on Cather's short story, "Eric Hermannson's Soul," titled Margaret Songs: Three Songs from Willa Cather (1996); and later, My Antonia (2000), based on Cather's novel of the same title. In Margaret Songs, Cather's poetry and short stories--specifically the character of Margaret Elliot--combine with Larsen's unique compositional style to create a surprising collaboration. This study explores how Larsen in these songs delves into the emotional and psychological depths of Margaret's character, not fully formed by Cather. It is only through Larsen's music and Cather's poetry that Margaret's journey through self-discovery and love become fully realized. This song cycle is a glimpse through the eyes of two prominent female artists on the societal pressures placed upon Margaret's character, many of which still resonate with women in today's culture. This study examines the work Margaret Songs by discussing Willa Cather, her musical influences, and the conditions surrounding the writing of "Eric Hermannson's Soul." It looks also into Cather's influence on Libby Larsen and the commission leading to Margaret Songs. Finally, a description of the musical, dramatic, and textual content of the songs completes this interpretation of the interactions of Willa Cather, Libby Larsen, and the character of Margaret Elliot.
ContributorsMcLain, Christi Marie (Author) / FitzPatrick, Carole (Thesis advisor) / Dreyfoos, Dale (Committee member) / Holbrook, Amy (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2013
151660-Thumbnail Image.png
Description
Puerto Rico has produced many important composers who have contributed to the musical culture of the nation during the last 200 years. However, a considerable amount of their music has proven to be difficult to access and may contain numerous errors. This research project intends to contribute to the accessibility

Puerto Rico has produced many important composers who have contributed to the musical culture of the nation during the last 200 years. However, a considerable amount of their music has proven to be difficult to access and may contain numerous errors. This research project intends to contribute to the accessibility of such music and to encourage similar studies of Puerto Rican music. This study focuses on the music of Héctor Campos Parsi (1922-1998), one of the most prominent composers of the 20th century in Puerto Rico. After an overview of the historical background of music on the island and the biography of the composer, four works from his art song repertoire are given for detailed examination. A product of this study is the first corrected edition of his cycles Canciones de Cielo y Agua, Tres Poemas de Corretjer, Los Paréntesis, and the song Majestad Negra. These compositions date from 1947 to 1959, and reflect both the European and nationalistic writing styles of the composer during this time. Data for these corrections have been obtained from the composer's manuscripts, published and unpublished editions, and published recordings. The corrected scores are ready for publication and a compact disc of this repertoire, performed by soprano Melliangee Pérez and the author, has been recorded to bring to life these revisions. Despite the best intentions of the author, the various copyright issues have yet to be resolved. It is hoped that this document will provide the foundation for a resolution and that these important works will be available for public performance and study in the near future.
ContributorsRodríguez Morales, Luis F., 1980- (Author) / Campbell, Andrew (Thesis advisor) / Buck, Elizabeth (Committee member) / Holbrook, Amy (Committee member) / Kopta, Anne (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2013
ContributorsYi, Joyce (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-22
153329-Thumbnail Image.png
Description
Seismic observations have revealed two large low shear velocity provinces (LLSVPs) in the lowermost mantle beneath Pacific and Africa. One hypothesis for the origin of LLSVPs is that they are caused by accumulation of subducted oceanic crust on the core-mantle boundary (CMB). Here, I perform high resolution geodynamical calculations to

Seismic observations have revealed two large low shear velocity provinces (LLSVPs) in the lowermost mantle beneath Pacific and Africa. One hypothesis for the origin of LLSVPs is that they are caused by accumulation of subducted oceanic crust on the core-mantle boundary (CMB). Here, I perform high resolution geodynamical calculations to test this hypothesis. The result shows that it is difficult for a thin (~ 6 km) subducted oceanic crust to accumulate on the CMB, and the major part of it is viscously stirred into the surrounding mantle. Another hypothesis for the origin of LLSVPs is that they are caused by thermochemical piles of more-primitive material which is remnant of Earth's early differentiation. In such case, a significant part of the subducted oceanic crust would enter the more-primitive reservoir, while other parts are either directly entrained into mantle plumes forming on top of the more-primitive reservoir or stirred into the background mantle. As a result, mantle plumes entrain a variable combination of compositional components including more-primitive material, old oceanic crust which first enters the more-primitive reservoir and is later entrained into mantle plumes with the more-primitive material, young oceanic crust which is directly entrained into mantle plumes without contacting the more-primitive reservoir, and depleted background mantle material. The result reconciles geochemical observation of multiple compositional components and varying ages of oceanic crust in the source of ocean-island basalts. Seismic studies have detected ultra-low velocity zones (ULVZs) in some localized regions on the CMB. Here, I present 3D thermochemical calculations to show that the distribution of ULVZs provides important information about their origin. ULVZs with a distinct composition tend to be located at the edges of LLSVPs, while ULVZs solely caused by partial melting tend to be located inboard from the edges of LLSVPs. This indicates that ULVZs at the edges of LLSVPs are best explained by distinct compositional heterogeneity, while ULVZs located insider of LLSVPs are better explained by partial melting. The results provide additional constraints for the origin of ULVZs.
ContributorsLi, Mingming (Author) / McNamara, Allen K (Thesis advisor) / Garnero, Edward J (Committee member) / Shim, Sang-Heon (Committee member) / Tyburczy, James (Committee member) / Clarke, Amanda (Committee member) / Arizona State University (Publisher)
Created2015
150140-Thumbnail Image.png
Description
The occurrence of exogenic, meteoritic materials on the surface of any world presents opportunities to explore a variety of significant problems in the planetary sciences. In the case of Mars, meteorites found on its surface may help to 1) constrain atmospheric conditions during their time of arrival; 2) provide insights

The occurrence of exogenic, meteoritic materials on the surface of any world presents opportunities to explore a variety of significant problems in the planetary sciences. In the case of Mars, meteorites found on its surface may help to 1) constrain atmospheric conditions during their time of arrival; 2) provide insights into possible variabilities in meteoroid type sampling between Mars and Earth space environments; 3) aid in our understanding of soil, dust, and sedimentary rock chemistry; 4) assist with the calibration of crater-age dating techniques; and 5) provide witness samples for chemical and mechanical weathering processes. The presence of reduced metallic iron in approximately 88 percent of meteorite falls renders the majority of meteorites particularly sensitive to oxidation by H2O interaction. This makes them excellent markers for H2O occurrence. Several large meteorites have been discovered at Gusev Crater and Meridiani Planum by the Mars Exploration Rovers (MERs). Significant morphologic characteristics interpretable as weathering features in the Meridiani suite of iron meteorites include a 1) large pit lined with delicate iron protrusions suggestive of inclusion removal by corrosive interaction; 2) differentially eroded kamacite and taenite lamellae on three of the meteorites, providing relative timing through cross-cutting relationships with deposition of 3) an iron oxide-rich dark coating; and 4) regmaglypted surfaces testifying to regions of minimal surface modification; with other regions in the same meteorites exhibiting 5) large-scale, cavernous weathering. Iron meteorites found by Mini-TES at both Meridiani Planum and Gusev Crater have prompted laboratory experiments designed to explore elements of reflectivity, dust cover, and potential oxide coatings on their surfaces in the thermal infrared using analog samples. Results show that dust thickness on an iron substrate need be only one tenth as great as that on a silicate rock to obscure its infrared signal. In addition, a database of thermal emission spectra for 46 meteorites was prepared to aid in the on-going detection and interpretation of these valuable rocks on Mars using Mini-TES instruments on both MER spacecraft. Applications to the asteroidal sciences are also relevant and intended for this database.
ContributorsAshley, James Warren (Author) / Christensen, Philip R. (Thesis advisor) / Sharp, Thomas G (Committee member) / Shock, Everett L (Committee member) / Hervig, Richard L (Committee member) / Zolotov, Mikhail Y (Committee member) / Arizona State University (Publisher)
Created2011
Description
The goal of this study is to gain a better understanding of earthquake distribution and regional tectonic structure across Arizona. To achieve this objective, I utilized seismic data from EarthScope's USArray Transportable Array (TA), which was deployed in Arizona from April 2006 to March 2009. With station spacing of approximately

The goal of this study is to gain a better understanding of earthquake distribution and regional tectonic structure across Arizona. To achieve this objective, I utilized seismic data from EarthScope's USArray Transportable Array (TA), which was deployed in Arizona from April 2006 to March 2009. With station spacing of approximately 70 km and ~3 years of continuous three-component broadband seismic data, the TA provided an unprecedented opportunity to develop the first seismicity catalog for Arizona without spatial sampling bias. In this study I developed a new data analysis workflow to detect smaller scale seismicity across a regional study area, which serves as a template for future regional analyses of TA data and similar datasets. The final event catalog produced for this study increased the total number of earthquakes documented in Arizona by more than 50% compared to the historical catalog, despite being generated from less than three years of continuous waveform data. I combined this new TA catalog with existing earthquake catalogs to construct a comprehensive historical earthquake catalog for Arizona. These results enabled the identification of several previously unidentified areas of seismic activity within the state, as well as two regions characterized by seismicity in the deeper (>20 km) crust. The catalog also includes 16 event clusters, 10 of which exhibited clear temporal clustering and swarm-like behavior. These swarms were distributed throughout all three physiographic provinces, suggesting that earthquake swarms occur regardless of tectonic or physiographic setting. I also conducted a case study for an earthquake swarm in June of 2007 near Theodore Roosevelt Lake, approximately 80 miles northeast of Phoenix. Families of events showed very similar character, suggesting a nearly identical source location and focal mechanism. We obtained focal mechanisms for the largest of these events, and found that they are consistent with normal faulting, expected in this area of the Arizona Transition Zone. Further, I observed no notable correlation between reservoir water level and seismicity. The occurrence of multiple historical earthquakes in the areas surrounding the reservoir indicates that this swarm was likely the result of tectonic strain release, and not reservoir induced seismicity.
ContributorsLockridge, Jeffrey Steven (Author) / Fouch, Matthew J (Thesis advisor) / Arrowsmith, Ramon (Thesis advisor) / Reynolds, Stephen J. (Committee member) / Arizona State University (Publisher)
Created2011
150470-Thumbnail Image.png
Description
Stratification is a dominant feature of all planetary interiors. Fine-scale structure associated with layering, as well as heterogeneities hold important clues on a planet's compositional, thermal, and dynamical state, as well as its evolution. This research centers on using data from seismic arrays, networks of seismic sensors, and array processing

Stratification is a dominant feature of all planetary interiors. Fine-scale structure associated with layering, as well as heterogeneities hold important clues on a planet's compositional, thermal, and dynamical state, as well as its evolution. This research centers on using data from seismic arrays, networks of seismic sensors, and array processing methodologies to map the fine scale structure in the Earth's upper mantle and deep layering in the Moon - Earth and Moon are the only two planetary bodies with seismic available data for such analyses. Small-scale structure in the Earth's upper mantle can give rise to seismic wave scattering. I studied high frequency data from the Warramunga Array in Australia using array seismology. I developed and employed back-projection schemes to map the possible upper mantle scattering or reflection locations. Mapped scatterers show good correlation to strong lateral P-wave velocity gradients in tomography models and may be associated with the complex tectonic history beneath north of Australia. The minimum scale of scatterers relates to the seismic wavelength, which is roughly between 5 and 10 km in the upper mantle for the frequencies we study. The Apollo Passive Seismic Experiment (APSE) consisted of four 3-component seismometers deployed between 1969 and 1972 that continuously recorded lunar ground motion until late 1977. I studied the deep lunar interior with array methods applied to the legacy APSE dataset. The stack results suggest the presence of a solid inner and fluid outer core, overlain by a partially molten boundary layer, but their reflector impedance contrasts and reflector depths are not well constrained. With a rapidly increasing number of available modern broadband data, I developed a package, Discovery Using Ducttape Excessively (DUDE), to quickly generate plots for a comprehensive view of earthquake data. These plots facilitate discovery of unexpected phenomena. This dissertation identifies evidence for small-scale heterogeneities in Earth's upper mantle, and deeper lunar layering structure. Planetary interiors are complex with the heterogeneities on many scales, and discontinuities of variable character. This research demonstrates that seismic array methods are well-suited for interrogating heterogeneous phenomena, especially considering the recent rapid expansion of easily available dense network data.
ContributorsLin, Pei-Ying (Author) / Garnero, Edward J. (Thesis advisor) / Fouch, Matthew (Committee member) / Mcnamara, Allen (Committee member) / Sharp, Thomas (Committee member) / Tyburczy, James (Committee member) / Arizona State University (Publisher)
Created2011