VictorJuiz/thesis huggingface dataset:
"E Ho'omau!" a study of Hawai'i teachers navigating change through generative praxis [electronic resource]

This study aims to make visible the practices of a group of teachers who are part of a community shift in Hawai'i, described here as the "Hawaiian Indigenous Movement for Education and Native Intelligence" (HIMENI). Revitalization of indigenous knowledge systems and practices has grown over the past thirty years in Hawai'i. The aims and outcomes that HIMENI teachers pursue are rooted in Hawaiian worldviews, and are aligned with Hawaiian cultural values; in some cases they differ greatly from the aims of conventional schooling. Study participants were enrolled in an inservice teacher education program and came from diverse schools across the state. During the five-year span of the ethnographic study, eight themes emerged, revealing a values-based conceptual framework that was coherently guiding HIMENI teachers across various learning contexts to strengthen the alignment between their principles and teaching practices. As they led their students through encounters with locally- and globally-valued knowledge, the eight themes helped them navigate change and build new teaching knowledge generatively—through embodied, contextualized knowledge that flowed in conversation with theory to shape practice. The HIMENI teachers' practices and pedagogies show clearly what "generative praxis" can look like, and what it can accomplish; a pedagogical model for generative praxis is proposed. HIMENI teachers cultivate generative praxis through their professional work, and also nurture its growth among their K-12 students. Analysis of the conceptual framework illuminates parallels between locally-recognized concepts and broadly-recognized constructs from the learning sciences that inform teacher practice, such as ecological models of context, embodied cognition, communities of practice, adaptive expertise and design thinking. Generative praxis is also aligned with enduring learning theories such those proposed by Vygotsky, Dewey, Bruner etc. Taken as a whole, the set of practices and processes used by this group of HIMENI teachers may be seen as an instantiation of "generative praxis"—an orientation to knowledge that powerfully promotes context-adaptive, dynamic knowledge development for teachers and learners alike. Standing alongside "content knowledge" and "pedagogical content knowledge"—two widely-recognized categories of knowledge for teaching—generative praxis gives us a new term to describe a third essential knowledge base for teaching: contextualized, iterative knowing-in-action. The teaching profession must acknowledge and cultivate generative praxis (by any name) if teacher educators and teachers are to successfully navigate the rapidly diversifying languages, cultures, knowledge(s) and routes of access to knowledge that are part of US contexts for learning in the 21st century.

Keywords: Education.
Advisor: Goldman Shelley
McDermott Ray (Raymond Patrick)
Nasir Na'ilah Suad advisor. Thesis advisor
Early-life failures in digital logic circuits [electronic resource]

Manufacturing tests detect defective integrated circuits (ICs) before they are shipped to customers. Early-life failures (ELF, also referred to as infant mortality failures) are caused by defective ICs that pass manufacturing tests but fail early in the field, much earlier than expected product lifetime. Such failures can hurt the reputation of IC suppliers, and can have consequences ranging from annoying computer crashes, loss of data and services, to financial and productivity losses, or even loss of human life. Major ELF causes include defects in transistor gate dielectrics and inter-metal dielectrics (IMD). Burn-in is traditionally used for ELF screening, where ICs are stressed at elevated voltage and temperature to accelerate defects so that they get detected during manufacturing tests. Burn-in accounts for a significant portion of manufacturing test costs, and there are serious concerns about its potentially reduced effectiveness in advanced technologies. Hence, low-cost burn-in alternatives are necessary. In this dissertation, we make the following contributions: 1. Using test chips over several IC technologies, we derive and experimentally demonstrate a new ELF signature for defects in transistor gate dielectrics: the presence of a gate-dielectric ELF transistor (i.e., a transistor with gate-dielectric defect that may result in ELF) inside a logic gate results in changes in delay of that logic gate over time before functional failures appear. This signature is distinct from gradual delay degradation effects exhibited by several circuit aging mechanisms. 2. We experimentally demonstrate that the ELF signature for IMD defects in advanced IC technologies (e.g., 28nm) is similar to that of transistor gate dielectrics. 3. We experimentally demonstrate that the derived ELF signature can be successfully detected using an on-chip clock control technique. 4. Using an industrial design with 8 processor cores supporting 64 hardware threads, we demonstrate the practicality of automatically generating special test patterns to detect ELF-induced changes in delays. Our results may be used to provide early indications of ELF-induced impending circuit failures during manufacturing tests, or during normal system operation for robust systems with built-in support for on-line self-test, diagnostics, and self-repair.

Keywords: Electrical Engineering.
Advisor: Mitra Subhasish primary advisor. Thesis advisor
Arbabian Amin advisor. Thesis advisor
Nishi Yoshio
Ecology of a threatened shorebird in an altered habitat: Bristle-thighed Curlews (Numenius tahitiensis) on Palmyra Atoll

Palmyra Atoll, USA has remained mostly uninhabited since construction and abandonment of a US naval base during World War II. However, the effects of Navy modifications made to the land and lagoons have persisted, affecting the extent, physical conditions, and benthic habitat quality of Palmyra’s lagoon sand flats. Sand flats provide critical non-breeding habitat for Bristle-thighed Curlews (Numenius tahitiensis) and the atoll hosts one of the largest wintering populations of curlews of any central Pacific island. N. tahitiensis are listed as “vulnerable” by the IUCN due to loss of non-breeding winter foraging grounds and predation by introduced mammals. Thus, Palmyra – an uninhabited island recently devoid of invasive predators – provides an appropriate setting for studying how land alterations have changed the availability of preferred lagoon flat habitat for curlews. Using camera trapping, observations of focal individuals, and quantification of prey availability and sediment characteristics to monitor curlew habitat selection across a gradient of different levels of historical anthropogenic impact, I found that curlew habitat preferences were not determined by the degree of Navy impact on lagoon flat habitat. Curlew abundance was most strongly correlated with availability of prey, such as spionid polychaetes (Malacoceros spp.), and coarse sediment composition. These findings provide new ecological information on a shorebird species of conservation concern and have implications, such as habitat loss, for land management at Palmyra Atoll and other curlew wintering grounds.

Keywords: Stanford Biology Department
Palmyra Atoll
Bristle-thighed Curlews
Numenius tahitiensis
habitat selection
Thesis
Advisor: Micheli Fiorenza
Dirzo Rodolfo
The effect of electrolyte gating on several solid state systems [electronic resource]

Recently, electrolyte gating has become a popular technique in studying the carrier density dependent physical properties in solid state materials, due to its capability of producing large carrier density modulation. The mechanism of conductance control by electrolyte gating has been widely accepted to be an electric double layer (EDL) capacitor model, which was originally proposed by Helmholtz in the 19th century to describe the electrolyte-electrode interface. However, this EDL picture is known for a number of imperfections. In this thesis, we take two transition metal oxide materials, namely the perovskite SrTiO$_3$ and rutile TiO$_2$, as examples, to show that the imperfections of EDL picture could manifest themselves in the physical properties one observes, and therefore should be included in drawing physical conclusions on electrolyte gated materials. Specifically, we show that electrolyte gated SrTiO$_3$ (001) shows two distinct electromagnetic transport regimes, which is consistent with a percolation picture, and suggests that the charge distribution in the EDL can be disordered. We also show that electrolyte gating effect on TiO$_2$ rutile is facet dependent, and strongly correlated with the TiO$_2$ surface energies. Gating cycles on TiO$_2$ rutile (101) shows large electrolyte dependent hysteresis, which is a signature of specific adsorption and ion-surface interactions. We further show that oxygen vacancy formation is more likely to be the origin of conductance in electrolyte gated TiO$_2$ rutile, and possibly SrTiO$_3$ as well. Electrochemical process could play a significant role even at low gate voltages. We finally study the electrolyte gating effect in the environment of oxygen, and propose it as a potential technique in detecting oxygen vacancy formation in electrolyte gated oxides. A number of other incomplete projects related to electrolyte gating will also be presented.

Keywords: Physics.
Advisor: Goldhaber-Gordon David
Harris J. S. (James Stewart)
Parkin Stuart S. P.
Effects of biochemical factors and mechanical loading on chondrogenesis of human adipose-derived stem cells [electronic resource]

Osteoarthritis (OA), a debilitating musculoskeletal disease that is characterized by cartilage degeneration, is one of the leading causes of disability in older adults. In 2006, it was estimated to affect 27 million adults in the United States, carrying with it a financial burden of over

Keywords: Mechanical Engineering.
Advisor: Levenston Marc Elliot primary advisor. Thesis advisor
Smith R. Lane (Robert Lane) advisor. Thesis advisor
Yang Fan (Bioengineering researcher and teacher) advisor. Thesis advisor
The effects of ground-based very low frequency transmitters on the ionosphere and magnetosphere [electronic resource]

The effects of ground-based very low frequency (VLF) transmitters on the ionosphere and magnetosphere are investigated. VLF transmitters, used primarily for Naval communications with submarines, are also capable of heating the ionosphere and inducing the precipitation of energetic electrons from the Earth's radiation belts. Controlled modulation experiments are performed with the 21.4 kHz, 424 kW VLF transmitter NPM in Lualualei, Hawaii, and physical effects of the NPM transmissions are studied with sub-ionospherically propagating VLF probe signals. Observed perturbations to the probe signal are not consistent with expectations from transmitter-induced electron precipitation nor to off-path scattering from a concentrated heating region near the transmitter but rather appear to be the result of scattering from extended lateral heating of the ionosphere by the NPM transmitter. A large-scale computational modeling framework confirms theoretically that this form of ionospheric heating can account for the observed probe signal modulations, establishing that the lateral extent of ionospheric heating due to VLF transmitters is several thousand kilometers, significantly greater than previously recognized. The trans-ionospheric propagation of VLF waves is also investigated as updated attenuation estimates are provided for multiple scenarios.

Keywords: Electrical Engineering.
Advisor: Inan Umran S. primary advisor. Thesis advisor
Spasojević Maria
Zebker Howard A. advisor. Thesis advisor
Efficient and high-speed reconfigurable transceiver for miniaturized wirelessly powered implants [electronic resource]

Small and versatile implantable devices that support distributed biosensing and localized operations could revolutionize modern medicine. Implantable systems will soon be an integral part of minimally invasive diagnostic, therapeutic, and surgical treatments to attain more accurate diagnosis and enhance the success rate of complex procedures. Wireless powering in combination with efficient high-speed reconfigurable transceivers that can accommodate a wide variety of biomedical applications and changing environmental conditions are essential for miniaturized medical implants. This thesis presents the detailed description of a wireless system architecture that enables the design of low-power battery-less implants. Wireless power transfer and very efficient high data rate communication techniques will be discussed. System and circuit design for two different miniaturized implantable devices, which were used to demonstrate these techniques, will be presented. The design challenges and tradeoffs of each of the projects will be discussed. The first project demonstrates efficient energy harvesting and forward data transfer as well as actuation for implants by providing up to several milliamps of current to power a magnetohydrodynamic propulsion system. The 3 mm x 4 mm prototype achieves 0.53 cm/sec speeds in fluid with a 0.06 T field using approximately 250 [microwatts], and receives data at up to 25 Mbps from a 2 W 1.86 GHz carrier. The second project illustrates the feasibility of low-power sensing for implants as well as an efficient reverse data link capable of robust operation in changing environmental conditions, which is common for implanted systems. The robustness was achieved through reconfigurable modulating load, pulse width, and data rate making this an attractive solution for a variety of applications, including the target application to develop a 1 mm3 implantable cardiac probe. External interrogator communicates with multiple devices using time domain multiple access. The implantable prototype consists of a 1 mm x 1 mm chip implemented in 65 nm CMOS process integrated with a 3D coil antenna and no other external components and consumes 10 [microwatts] while demonstrating wireless powering and two-way communication through 35 mm of tissue.

Keywords: Electrical Engineering.
Advisor: Poon Ada Shuk Yan
Lee Thomas H.
Meng Teresa H. advisor. Thesis advisor
Murmann Boris advisor. Thesis advisor
Efficient and invisible [electronic resource] : hybrid metal-semiconductor nanoscale photodetectors

Development of ultra-compact, silicon-compatible, and functional optoelectronic devices is essential for advancing technologies in emerging areas of optical interconnects solid state lighting, renewable energy. Photodetectors play a key role of interfacing between photonics and electronics but are plagued by a fundamental discrepancy between the dimension of state-of-the-art electronic devices and the optical diffraction limit. As we start to scale optoelectronic devices to the nanoscale dimensions, it is no longer possible to consider the optical properties of the absorbing semiconductor material alone without its surrounding components such as metallic contacts. On the other hand, nanotechnology is enabling the realization of hybrid devices and circuits in which nanoscale metal and semiconductor building blocks are woven together in a highly integrated fashion. Hereby, we will describe several optoelectronic devices for which the geometrical properties of the constituent semiconductor and metallic nanostructures are tuned in conjunction with the materials properties to realize multiple functions in the same physical space. In particular, we will demonstrate a series of photodetectors in which nanoscale semiconductor wires were used to boost light absorption due to excitation of optical resonances and the nanoscale metallic electrical contacts have been designed to either render the device 'invisible' over a broad frequency range, or act as optical antenna which funnels incident light into the device to further enhance efficiency. These structures belongs to a new class of devices that capitalize on the notion that nanostructures have a limited number of resonant, geometrically tunable optical modes whose hybridization and inter-modal interference can be tailored in a myriad of useful ways for enhanced optoelectronic devices with novel functionalities.

Keywords: Materials Science and Engineering.
Advisor: Brongersma Mark L. primary advisor. Thesis advisor
Cui Yi
Salleo Alberto
An efficient solution procedure for multi-species reacting navier-stokes equations [electronic resource]

Many countries are planning missions to Mars and the moon, which has made the ability to safely pass the most dangerous phase of the mission -- atmospheric entry -- a research priority. Prediction of the extreme aerodynamic conditions experienced during atmospheric entry is essential for safe mission, but there is currently limited experimental data to base these on. Numerical procedures are heavily used in the design of spacecraft, however, hypersonic flows are extremely challenging and computationally expensive to simulate owing to their complex physics. High temperatures induce chemical reactions in the flow, which ionize the molecular structure of the gas particles into reacting chemical species. In addition, the flow interacts chemically with the surface of the vehicle; the cooler walls of the vehicle act as a catalyst in promoting the recombination reactions which significantly affect the rate of heat transfer from the flow to the surface. These phenomena make the size of the set of governing equations very large, and extremely stiff to solve.

Keywords: Aeronautics and Astronautics.
Advisor: Alonso Juan José
Cappelli Mark A. (Mark Antony) advisor. Thesis advisor
MacCormack R. W. (Robert William)
Palacios Francisco (Research associate)
Electrical engineering and project delivery challenges in large-scale photovoltaic systems and data centers [electronic resource]

There are workflow inefficiencies and engineering knowledge deficits in large-scale photovoltaic system construction projects. This dissertation compiles the results of my doctoral research into (1) identifying and understanding the underlying causes for some of these issues and (2) developing mechanisms to address them. I assert that many workflow inefficiencies stem from sub-optimal organizational constructs--such as extreme project supply chain fragmentation and competitive bidding--prevalent throughout the construction industry. These constructs also retard knowledge development and hence influence knowledge voids in fairly new project types/scopes, such as large-scale photovoltaic systems. In response, I developed new calculation models and analysis methods to fill knowledge voids related to electrical wiring, component layouts, and electric arc-flash safety hazards in these systems. These contributions give engineers better understandings of the performance, reliability, operator safety, and cost implications of the related design choices and facilitate model-based design-analyses. Such analyses facilitate further knowledge development and improved system quality through metric-based optimization, examples of which are presented in this dissertation. This dissertation also communicates workflow inefficiencies and knowledge deficits in data center construction and operation--a project type that is also fairly new and heavily dominated by the electrical construction activities. This secondary focus is a logical extension of my primary research goals and conveys how the sub-optimal organizational constructs negatively impact newly popular construction types other than large-scale photovoltaic projects. As tertiary contributions, I demonstrate the use of systems engineering principles in construction projects and related design-automation software tools to illustrate how these principles can be used to improve stakeholder value and system lifecycle considerations. These contributions are meant to encourage increased use of systems engineering, lean construction, and/or other lifecycle based management processes in construction projects as a means of tackling the sub-optimal organizational constructs. Additionally, I introduce a new method for managing probabilistic uncertainties in popular numerical-based decision-making tools, such as Quality Function Deployment matrices, which are used extensively in systems engineering. This method is meant to increase confidence in the use of such tools and promote further development of (and/or research into) mathematical or scientific decision-making frameworks.

Keywords: Civil and Environmental Engineering.
Advisor: Levitt Raymond E. primary advisor. Thesis advisor
Fischer Martin
Rajagopal Ram advisor. Thesis advisor
Weiss Stanley
Electrochemical reduction of carbon dioxide on transition metal surfaces [electronic resource]

Electrochemical carbon dioxide reduction reaction (CO2RR) is a promising way to store energy from intermittent electricity sources (ie. wind and solar) and for the synthesis of carbon-based compounds that are currently derived from fossil fuels. To commercialize this process, catalysts that selectively reduce CO2 at low overpotential are needed. Research in this area is hindered by the experimental difficulty of comparing catalyst activity. This thesis begins with the development of a custom electrolysis cell that can be coupled to product detection with NMR and GC. This method allows for accurate voltage measurement and the quantification of all possible products to give the most complete characterization of CO2RR activity available to date. The CO2RR activity of Cu metal is well-studied, but application of this more sensitive experimental method lead to the identification of five novel products: glyoxal, glycolaldehyde, ethylene glycol, hydroxyacetone, and acetone. The CO2RR product identities and their potential dependence inspired the hypothesis that the enol and diol forms of the products may be the active intermediate species on the electrode surface. CO is believed to be an intermediate of CO2RR to methane and ethylene and the direct electrochemical reduction of CO confirmed that it is also a possible intermediate in the formation of many of the novel products observed as well. After Cu, the activity of Au, Ag, Zn, Ni, Pt, and Fe for CO2RR was also measured using the same experimental method. This represents the most complete dataset of transition metal activity available and reveals several important trends. A plot of CO2RR activity vs. CO binding energy places Au at the top of the volcano, suggesting that it has a near optimal binding energy for CO (and other intermediates) within the pure metals. A strong CO binding energy is also correlated with an early onset potential for HER and methane/methanol formation. The widespread use of CO2RR will require a catalyst with higher activity than any of the pure metals. Efforts to improve activity began by alloying Fe and Ni, which are poor overall CO2RR catalysts individually, but do produce hydrocarbon products. Alloying decreased the overpotential of needed for methane formation, demonstrating that alloying is a promising method of catalyst improvement.

Keywords: Chemistry.
Advisor: Jaramillo Thomas Francisco primary advisor. Thesis advisor
Chidsey Christopher E. D. (Christopher Elisha Dunn)
Hodgson Keith