9 research outputs found

    Parameter Estimation for Propagation along Random Rough Surface by Using Line of Sight Data

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    The structural and temporal constraints on regional propylitic alteration: A study of the Quellaveco Cu-Mo porphyry district, Peru

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    The propylitic halo is one of the least studied parts of the porphyry system, however advancements in geochemical vectoring and fertility studies have highlighted the importance of propylitic alteration for the future of porphyry exploration. This study furthers our understanding of the development of district-scale propylitic alteration by applying an innovative approach which considers the potential spatial, structural and temporal controls on district-scale propylitic alteration, generating a 4-dimensional model of the evolution of propylitic alteration in a specific region: the giant Quellaveco Cu-Mo porphyry in southern Peru. Over 20,000 structural data points and 107 samples were collected from two ~25 km transects in the Quellaveco region. SEM analysis of 82 samples yielded grain-scale petrographic and textural information of veining and alteration assemblages. This enabled the classification of 18 wall rock and vein alteration assemblages 10 of which represented propylitic-related assemblages. Specifically identified sites were selected from the propylitic minerals for geochronological (apatite, titanite, epidote and zircon) and geochemical trace element analysis (epidote and chlorite) using the LA-ICP-MS. Dating revealed an extensive period of propylitic alteration between 72-60 Ma with an alteration maximum concentrating at 65-69 Ma. This peak in propylitic alteration occurred ~8-12 My prior to the onset of mineralisation at the known porphyry regional centers: Quellaveco (58.4-54.3 Ma); Toquepala (57.0-54.0 Ma) and Cuajone (56.5-53.0 Ma). Fluctuations of propylitic alteration continued throughout this period, with geothermic and geochemical vectors indicating a period of high temperature fluids between 72-68 Ma, consistent with early Yarabamba Batholith emplacement. The principal NW-SE faults act as major fluid conduits during this period, with specifically the NNW-SSE Puca-Porquene splay-fault. Where the NW-SE fault intersect the major NE-SW faults there are apparent areas of fluid localization. In summary, this project’s multi-disciplinary approach elucidates the temporal and spatial complexity of the development of propylitic alteration in porphyry regions

    Data-Driven Methods for Geometric Systems

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    The tools of geometric mechanics provide a compact representation of locomotion dynamics as ``the reconstruction equation''. We have found this equation yields a convenient form for estimating models directly from observation data. This convenience draws from the method's relatively rare feature of providing high accuracy models with little effort. By little effort, we point to the modeling process's low data requirements and the property that nothing about the implementation changes when substituting robot kinematics, material properties, or environmental conditions, as long as some intuitive baseline features of the dynamics are shared. We have applied data-driven geometric mechanics models toward optimizing robot behaviors both physical and simulated, exploring robots' ability to recover from injury, and efficiently creating libraries of maneuvers to be used as building blocks for higher-level robot tasks. Our methods employed the tools of data-driven Floquet analysis, providing a phase that we used as a means of grouping related measurements, allowing us to estimate a reconstruction equation model as a function of phase in the neighborhood of an observed behavior. This tool allowed us to build models at unanticipated scales of complexity and speed. Our use of a perturbation expansion for the geometric terms led to an improved estimation procedure for highly damped systems containing nontrivial but non-dominating amounts of momentum. Analysis of the role of passivity in dissipative systems led to another extension of the estimation procedure to robots with high degrees of underactuation in their internal shape, such as soft robots. This thesis will cover these findings and results, simulated and physical, and the surprising practicality of data-driven geometric mechanics.PHDRoboticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/168033/1/babitt_1.pd

    Higher dimensional time-energy entanglement

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    Judging by the compelling number of innovations based on taming quantum mechanical effects, such as the development of transistors and lasers, further research in this field promises to tackle further technological challenges in the years to come. This statement gains even more importance in the information processing scenario. Here, the growing data generation and the correspondingly higher need for more efficient computational resources and secure high bandwidth networks are central problems which need to be tackled. In this sense, the required CPU minituarization makes the design of structures at atomic levels inevitable, as foreseen by Moore's law. From these perspectives, it is necessary to concentrate further research efforts into controlling and manipulating quantum mechanical systems. This enables for example to encode quantum superposition states to tackle problems which are computationally NP hard and which therefore cannot be solved efficiently by classical computers. The only limitation affecting these solutions is the low scalability of existing quantum systems. Similarly, quantum communication schemes are devised to certify the secure transmission of quantum information, but are still limited by a low transmission bandwidth. This thesis follows the guideline defined by these research projects and aims to further increase the scalability of the quantum mechanical systems required to perform these tasks. The method used here is to encode quantum states into photons generated by spontaneous parametric down-conversion (SPDC). An intrinsic limitation of photons is that the scalability of quantum information schemes employing them is limited by the low detection efficiency of commercial single photon detectors. This is addressed by encoding higher dimensional quantum states into two photons, increasing the scalability of the scheme in comparison to multi-photon states. Further on, the encoding of quantum information into the emission-time degree of freedom improves its applicability to long distance quantum communication schemes. By doing that, the intrinsic limitations of other schemes based on the encoding into the momentum and polarization degree of freedom are overcome. This work presents results on a scalable experimental implementation of time-energy encoded higher dimensional states, demonstrating the feasibility of the scheme. Further tools are defined and used to characterize the properties of the prepared quantum states, such as their entanglement, their dimension and their preparation fidelity. Finally, the method of quantum state tomography is used to fully determine the underlying quantum states at the cost of an increased measurement effort and thus operation time. It is at this point that results obtained from the research field of compressed sensing help to decrease the necessary number of measurements. This scheme is compared with an adaptive tomography scheme designed to offer an additional reconstruction speedup. These results display the scalability of the scheme to bipartite dimensions higher than 2x8, equivalent to the encoding of quantum information into more than 6 qubits.Es ist in den letzten Jahren immer deutlicher geworden, dass weitere Forschung zur Untersuchung von quantenmechanischen Systemen durchgeführt werden muss um die wachsenden Probleme in der heutigen Informationstechnologie zu adressieren. Insbesondere sticht hier die exponentiell wachsende Nachfrage nach Computerressourcen und nach sicheren Kommunikationsprotokollen mit hoher Bandbreite hervor, um der weiter wachsenden Datengenerationsrate standzuhalten. Dies stösst auf fundamentale Grenzen, wie die erforderliche Miniaturisierung von Prozessorstrukturen (CPUs) auf atomare Dimensionen demonstriert. Von dieser Perspektive her ist es erforderlich weitere Forschung zur Kontrolle und Manipulation von Quantenzuständen durchzuführen, wie sie zum Beispiel im Feld der Quanteninformation erfolgt ist. Diese Strategie ermöglicht es von weiteren Eigenschaften der Quantenmechanik, wie zum Beispiel der Präparation von Superpositionszuständen, Gebrauch zu machen. Dies ist insbesondere relevant, da es ermöglicht NP harte Probleme zu lösen, die durch klassische Computer nicht effizient gelöst werden können. Allerdings sind bisher experimentell realisierte quantenmechanische Systeme noch nicht skalierbar genug um den Anforderungen der klassischen Technologie gerecht zu werden. Ähnlichen Argumenten folgend sind Quantenkommunikationssysteme, die die Sicherheit von Kommunikationsprotokolle zertifizieren können, noch nicht in der Lage angemessene Bandbreiten zu gewährleisten. Diese Doktorarbeit gliedert sich diesen Forschungsprojekten an, mit dem Ziel die Skalierbarkeit von quantenmechanischen Systemen zu vergrössern und entsprechend den genannten Anforderungen gerecht zu machen. Die Strategie die hier verfolgt wird basiert auf die Kodierung von Quantenzuständen in Photonenpaare, die durch den Prozess der Spontanen Parametrischen Down-conversion (SPDC) erzeugt werden. Dieses Verfahren bringt allerdings eine limitierte Skalierbarkeit der Quantensysteme mit sich, da die Detektionseffizienz von kommerziell erhältlichen Einzelphotonendetektoren limitiert ist. Dieses Problem wird in dieser Arbeit umgangen indem die Quantenzustände in höher dimensionale Hilberträume eines Zweiphotonenzustands kodiert werden, was einen deutlichen Vorteil gegenüber der Kodierung in einen Mehrphotonenzustand darstellt. Darüber hinaus ermöglicht die Kodierung der Quantenzustände in den Emissionszeit Freiheitsgrad der Photonen intrinsische Vorteile bei ihrer Anwendung auf die Quantenkommunikation. Hier ist insbesondere der Vorteil gegenüber der Kodierung in den Impuls- und Polarisationsfreiheitsgrad gemeint, die durch deutliche Einschränkungen bei der Transmission über lange Strecken gekennzeichnet sind. Mit einem Augenmerk auf diese Ziele wird in dieser Arbeit die experimentelle Umsetzbarkeit des beschriebenen Schemas gezeigt. Dies wurde durch die Anwendung von geeigneten Maßen wie die Verschränkung, Dimension und Präparationsfidelity auf die generierten Zustände quantifiziert. Insbesondere bei der Abschätzung der Fidelity wurde von Forschungsergebnissen rund um Compressed Sensing Gebrauch gemacht und weiter mit einem adaptiven Messschema kombiniert, um die effektive Betriebszeit dieser Systeme zu verringern. Dies ist für die weitere skalierbare Anwendung zur Quanteninformationsverarbeitung von Vorteil. Die Ergebnisse verdeutlichen, dass eine Skalierbarkeit der Dimension des Systems auf grösser als 2x8 Dimensionen, äquivalent zur Dimension eines 6-Qubit Zustands, in der Reichweite einer experimentellen Umsetzung liegt

    Remote Sensing Observations of Tundra Snow with Ku- and X-band Radar

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    Seasonal patterns of snow accumulation in the Northern Hemisphere are changing in response to variations in Arctic climate. These changes have the potential to influence global climate, regional hydrology, and sensitive ecosystems as they become more pronounced. To refine our understanding of the role of snow in the Earth system, improved methods to characterize global changes in snow extent and mass are needed. Current space-borne observations and ground-based measurement networks lack the spatial resolution to characterize changes in volumetric snow properties at the scale of ground observed variation. Recently, radar has emerged as a potential complement to existing observation methods with demonstrated sensitivity to snow volume at high spatial resolutions (< 200 m). In 2009, this potential was recognized by the proposed European Space Agency Earth Explorer mission, the Cold Regions High Resolution Hydrology Observatory (CoReH2O); a satellite based dual frequency (17.2 and 9.6 GHz) radar for observation of cryospheric variables including snow water equivalent (SWE). Despite increasing international attention, snow-radar interactions specific to many snow cover types remain unevaluated at 17.2 or 9.6 GHz, including those common to the Canadian tundra. This thesis aimed to use field-based experimentation to close gaps in knowledge regarding snow-microwave interaction and to improve our understanding of how these interactions could be exploited to retrieve snow properties in tundra environments. Between September 2009 and March 2011, a pair of multi-objective field campaigns were conducted in Churchill, Manitoba, Canada to collect snow, ice, and radar measurements in a number of unique sub-arctic environments. Three distinct experiments were undertaken to characterize and evaluate snow-radar response using novel seasonal, spatial, and destructive sampling methods in previously untested terrestrial tundra environments. Common to each experiment was the deployment of a sled-mounted dual-frequency (17.2 and 9.6 GHz) scatterometer system known as UW-Scat. This adaptable ground-based radar system was used to collect backscatter measurements across a range of representative tundra snow conditions at remote terrestrial sites. The assembled set of measurements provide an extensive database from which to evaluate the influence of seasonal processes of snow accumulation and metamorphosis on radar response. Several advancements to our understanding of snow-radar interaction were made in this thesis. First, proof-of-concept experiments were used to establish seasonal and spatial observation protocols for ground-based evaluation. These initial experiments identified the presence of frequency dependent sensitivity to evolving snow properties in terrestrial environments. Expanding upon the preliminary experiments, a seasonal observation protocol was used to demonstrate for the first time Ku-band and X-band sensitivity to evolving snow properties at a coastal tundra observation site. Over a 5 month period, 13 discrete scatterometer observations were collected at an undisturbed snow target where Ku-band measurements were shown to hold strong sensitivity to increasing snow depth and water equivalent. Analysis of longer wavelength X-band measurements was complicated by soil response not easily separable from the target snow signal. Definitive evidence of snow volume scattering was shown by removing the snowpack from the field of view which resulted in a significant reduction in backscatter at both frequencies. An additional set of distributed snow covered tundra targets were evaluated to increase knowledge of spatiotemporal Ku-band interactions. In this experiment strong sensitivities to increasing depth and SWE were again demonstrated. To further evaluate the influence of tundra snow variability, detailed characterization of snow stratigraphy was completed within the sensor field of view and compared against collocated backscatter response. These experiments demonstrated Ku-band sensitivity to changes in tundra snow properties observed over short distances. A contrasting homogeneous snowpack showed a reduction in variation of the radar signal in comparison to a highly variable open tundra site. Overall, the results of this thesis support the single frequency Ku-band (17.2 GHz) retrieval of shallow tundra snow properties and encourage further study of X-band interactions to aid in decomposition of the desired snow volume signal.4 month

    Towards a better understanding of the mechanisms underlying myosin-related congenital myopathies

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    Myosin is a family of proteins that plays a crucial role in generating force and motion by interacting with actin filaments in skeletal muscle. Myosin molecules notably contain heavy chain (MyHC) isoforms that have different functional capabilities. Mutations in one of its isoforms, MyHC I/β (encoded by the MYH7 gene) have been reported in humans, associated with muscle weakness and have led to two main distinct skeletal muscle diseases, Laing Distal Myopathy (LDM) and Myosin Storage Myopathy (MSM). The pathophysiological mechanisms by which subtle amino acid changes in the LMM region of MyHC I/β molecules leading to such variable skeletal muscle phenotypes in LDM and MSM patients remain poorly understood. Using a wide range of human MYH7 patient muscle biopsy samples, investigation of primary biophysical defects in the presence of defective MyHC I/β molecules including myosin filament length has revealed no change but rather a shift in myosin head positioning into a disordered relaxed state (DRX). On the road to generating a zebrafish LDM and MSM disease model, several genes were identified to be orthologous to human MYH7. Amongst orthologous genes, smyhc1 was targeted for genome editing using CRISPR/Cas9 to generate a loss of function model. Loss of smyhc1 led to early developmental defects, however, continued to grow to adulthood with no observable muscle defects. Smyhc1 null zebrafish are replaced and compensated by smyhc2 and smyhc3 in adult zebrafish. Work ongoing to generate large deletion of smyhc locus to understand the role of slow MyHC in sarcomere assembly during early developmental stages through to adulthood. It is concluded that in the presence of LDM mutations in the MyBP-C binding domain, myosin heads in the SRX state are destabilised, and zebrafish smyhc1 is orthologous to human MYH7 but only functions during the early stages of development. Continued work to generate knockout of smyhc locus may describe the function of smyhc2 and smyhc3 in later stages of development in the quest to model the progressive phenotype in LDM and MSM patients

    Radiation Simulation for Air and Oxy-fuel Combustion using Computational Fluid Dynamics

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    Coal consumption is predicted to account for about 21% of the total global primary energy in 2040 and this continues to be a challenge for global warming and air pollution. Oxyfuel combustion is one of the leading options for carbon capture and storage (CCS) technologies to reduce the impact on the environment. Initially this technology has been studied successfully on small-scale facilities but it needs to be developed for large-scale applications. CFD has been demonstrated to be a key tool for the development and optimisation of pulverised coal combustion processes and it is still an important tool for new designs and retro-fitting of conventional power plants for oxyfuel combustion. Radiation heat transfer plays an important role, influencing the overall combustion efficiency, pollutant formation and flame ignition and propagation. This thesis focuses on the radiation properties of the particles as well as gas property models on the overall influence of the prediction of the formation of NOx pollutants in pulverised coal combustion. The radiative properties of the particles are investigated with a focus on the effect of the optical properties and approximate solutions to determine the radiative properties, with different experimental data for the optical properties and approximate solutions being employed. The effects of the radiative properties on the radiative heat transfer are investigated in three dimensional enclosures for small and large-scale furnaces and implemented on a 250 kW pilot scale combustion for both air and oxyfuel conditions. The results from the study highlights the best selection for the particle properties for simulations in small and large-scale pulverised coal furnaces and employing radiation models for the gases and particles to improve the NOx predictions in pulverised coal combustion under air and oxy-fired environments

    Higher dimensional time-energy entanglement

    Get PDF
    Judging by the compelling number of innovations based on taming quantum mechanical effects, such as the development of transistors and lasers, further research in this field promises to tackle further technological challenges in the years to come. This statement gains even more importance in the information processing scenario. Here, the growing data generation and the correspondingly higher need for more efficient computational resources and secure high bandwidth networks are central problems which need to be tackled. In this sense, the required CPU minituarization makes the design of structures at atomic levels inevitable, as foreseen by Moore's law. From these perspectives, it is necessary to concentrate further research efforts into controlling and manipulating quantum mechanical systems. This enables for example to encode quantum superposition states to tackle problems which are computationally NP hard and which therefore cannot be solved efficiently by classical computers. The only limitation affecting these solutions is the low scalability of existing quantum systems. Similarly, quantum communication schemes are devised to certify the secure transmission of quantum information, but are still limited by a low transmission bandwidth. This thesis follows the guideline defined by these research projects and aims to further increase the scalability of the quantum mechanical systems required to perform these tasks. The method used here is to encode quantum states into photons generated by spontaneous parametric down-conversion (SPDC). An intrinsic limitation of photons is that the scalability of quantum information schemes employing them is limited by the low detection efficiency of commercial single photon detectors. This is addressed by encoding higher dimensional quantum states into two photons, increasing the scalability of the scheme in comparison to multi-photon states. Further on, the encoding of quantum information into the emission-time degree of freedom improves its applicability to long distance quantum communication schemes. By doing that, the intrinsic limitations of other schemes based on the encoding into the momentum and polarization degree of freedom are overcome. This work presents results on a scalable experimental implementation of time-energy encoded higher dimensional states, demonstrating the feasibility of the scheme. Further tools are defined and used to characterize the properties of the prepared quantum states, such as their entanglement, their dimension and their preparation fidelity. Finally, the method of quantum state tomography is used to fully determine the underlying quantum states at the cost of an increased measurement effort and thus operation time. It is at this point that results obtained from the research field of compressed sensing help to decrease the necessary number of measurements. This scheme is compared with an adaptive tomography scheme designed to offer an additional reconstruction speedup. These results display the scalability of the scheme to bipartite dimensions higher than 2x8, equivalent to the encoding of quantum information into more than 6 qubits.Es ist in den letzten Jahren immer deutlicher geworden, dass weitere Forschung zur Untersuchung von quantenmechanischen Systemen durchgeführt werden muss um die wachsenden Probleme in der heutigen Informationstechnologie zu adressieren. Insbesondere sticht hier die exponentiell wachsende Nachfrage nach Computerressourcen und nach sicheren Kommunikationsprotokollen mit hoher Bandbreite hervor, um der weiter wachsenden Datengenerationsrate standzuhalten. Dies stösst auf fundamentale Grenzen, wie die erforderliche Miniaturisierung von Prozessorstrukturen (CPUs) auf atomare Dimensionen demonstriert. Von dieser Perspektive her ist es erforderlich weitere Forschung zur Kontrolle und Manipulation von Quantenzuständen durchzuführen, wie sie zum Beispiel im Feld der Quanteninformation erfolgt ist. Diese Strategie ermöglicht es von weiteren Eigenschaften der Quantenmechanik, wie zum Beispiel der Präparation von Superpositionszuständen, Gebrauch zu machen. Dies ist insbesondere relevant, da es ermöglicht NP harte Probleme zu lösen, die durch klassische Computer nicht effizient gelöst werden können. Allerdings sind bisher experimentell realisierte quantenmechanische Systeme noch nicht skalierbar genug um den Anforderungen der klassischen Technologie gerecht zu werden. Ähnlichen Argumenten folgend sind Quantenkommunikationssysteme, die die Sicherheit von Kommunikationsprotokolle zertifizieren können, noch nicht in der Lage angemessene Bandbreiten zu gewährleisten. Diese Doktorarbeit gliedert sich diesen Forschungsprojekten an, mit dem Ziel die Skalierbarkeit von quantenmechanischen Systemen zu vergrössern und entsprechend den genannten Anforderungen gerecht zu machen. Die Strategie die hier verfolgt wird basiert auf die Kodierung von Quantenzuständen in Photonenpaare, die durch den Prozess der Spontanen Parametrischen Down-conversion (SPDC) erzeugt werden. Dieses Verfahren bringt allerdings eine limitierte Skalierbarkeit der Quantensysteme mit sich, da die Detektionseffizienz von kommerziell erhältlichen Einzelphotonendetektoren limitiert ist. Dieses Problem wird in dieser Arbeit umgangen indem die Quantenzustände in höher dimensionale Hilberträume eines Zweiphotonenzustands kodiert werden, was einen deutlichen Vorteil gegenüber der Kodierung in einen Mehrphotonenzustand darstellt. Darüber hinaus ermöglicht die Kodierung der Quantenzustände in den Emissionszeit Freiheitsgrad der Photonen intrinsische Vorteile bei ihrer Anwendung auf die Quantenkommunikation. Hier ist insbesondere der Vorteil gegenüber der Kodierung in den Impuls- und Polarisationsfreiheitsgrad gemeint, die durch deutliche Einschränkungen bei der Transmission über lange Strecken gekennzeichnet sind. Mit einem Augenmerk auf diese Ziele wird in dieser Arbeit die experimentelle Umsetzbarkeit des beschriebenen Schemas gezeigt. Dies wurde durch die Anwendung von geeigneten Maßen wie die Verschränkung, Dimension und Präparationsfidelity auf die generierten Zustände quantifiziert. Insbesondere bei der Abschätzung der Fidelity wurde von Forschungsergebnissen rund um Compressed Sensing Gebrauch gemacht und weiter mit einem adaptiven Messschema kombiniert, um die effektive Betriebszeit dieser Systeme zu verringern. Dies ist für die weitere skalierbare Anwendung zur Quanteninformationsverarbeitung von Vorteil. Die Ergebnisse verdeutlichen, dass eine Skalierbarkeit der Dimension des Systems auf grösser als 2x8 Dimensionen, äquivalent zur Dimension eines 6-Qubit Zustands, in der Reichweite einer experimentellen Umsetzung liegt
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