VictorJuiz/thesis huggingface dataset:
In-situ Analysis of Zinc Electrodeposition within an Ionic Liquid Electrolyte

Ionic liquids have received considerable attention as an alternative electrolyte for rechargeable battery systems. The goal of this investigation is to develop an understanding on the electrodeposition behavior of zinc within ionic liquid electrolytes and determine whether the unique properties of ionic liquids may allow for enhanced cyclability of the zinc electrode for rechargeable battery systems./nThree different analysis techniques are employed for the investigation of the zinc deposition behavior within an imidazolium based ionic liquid electrolyte. First, the electrochemical behavior of the electrodeposition behavior is analyzed by cyclic voltammetry and potential step methods. Second, in-situ atomic force microscopy (AFM) is conducted to investigate the morphological evolution of zinc during electrodeposition. Finally, in-situ ultra-small-angle X-ray scattering (USAXS) is conducted during the electrodeposition of zinc to understand how the electrode surface evolves during electrodeposition and help confirm the results obtained from the in-situ AFM analysis./nThe ionic liquid electrolyte chosen for the investigation of zinc electrodeposition is an imidazolium based system consisting of zinc trifluoromethanesulfonate (Zn(OTf)2) dissolved within 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate (BMIm OTf), and electrodeposition analysis is conducted on a Pt disk electrode. The behavior of Zn/Zn(II) within the ionic liquid electrolyte is analyzed at various deposition overpotentials, Zn(OTf)2 concentrations, and temperatures./nThree distinct morphological behaviors are observed during the in-situ AFM analysis: growth of boulder like morphology, growth dominated by favorably oriented grains, and the formation of surface instabilities that manifested as agglomerate islands. The electrodeposition growth of Zn dominated by favorably oriented grains obtains a steady state where the surface roughness remained constant despite continued growth. The in-situ USAXS analysis confirms the results observed by the in-situ AFM analysis. In addition, the USAXS data shows that the zinc deposition behavior is hierarchical whereby the main scattering entities exhibited a sub-structure that remains constant in size with continued deposition./nThe results of this research indicate that zinc deposition within an ionic liquid electrolyte can obtain a compact and dense morphology. Furthermore, the morphology can evolve under a steady state condition under certain deposition parameters identified by this research. The improved deposition morphology of zinc within ionic liquid electrolytes may help improve the cycling performance of the zinc electrode and help make zinc based rechargeable batteries a viable alternative for energy storage applications.

Advisor: Evans, James W.
Health Equity in a New Urbanist Environment: Land Use Planning and Community Capacity Building in Fresno, CA

A tale of two cities. The Mason-Dixon line. The Berlin Wall. Fresnans have evoked a variety of metaphors to describe the spatial divide between the rich, clean and white neighborhoods in the north and the southern areas housing the poor, polluting industries and communities of color that has characterized urban development in the city since its inception. The narrative explaining this spatial inequality has been remarkably consistent over time - sprawl fueled by aggressive developers, corrupt city councilmen and the market pushed the city limits ever farther northeast, abandoning the older neighborhoods to the south where the poor and immigrant communities settled and were too disorganized to counter the government's neglect./nThe spatial concentration of the poor, people of color and unwanted land uses can be seen in cities around the country and is identified by public health scholars to be a key driver of the disparities in health between racial and socio-economic groups. City governments are increasingly returning to their core and investing in New Urbanist and Smart Growth strategies to transform these older, more densely developed neighborhoods as the drive for environmental sustainability, walkable neighborhoods, and the attraction of creative urban residents grows. The potential effects of such efforts on the health and wellbeing of the existing residents, however, remains under explored. This dissertation asks if and how the new planning paradigms that use public health as a goal and organizing principle significantly change planning practice and lead to the re-distribution of environmental risks and resources to reduce health disparities? I investigate this question through three case studies of in Fresno a) a downtown revitalization plan, b) the general plan update, and c) a foundation based community development effort to increase the power of South Fresno residents to engage in planning./nFollowing a year of fieldwork I find that everyone is talking about healthy neighborhoods, however for whom and how to achieve them appear to be quite different. While community groups seek to improve the living conditions of the poor residents of South Fresno and ensure their ability to stay in a revitalized downtown, planners are focusing on attracting wealthier residents and actively avoiding any talk about equity, affordable housing and public investment. Thus, although health seems to be providing a unifying framework in terms of a vision for the physical environment, it does not ultimately resolve the inherent tensions between community and economic development.

Advisor: Corburn, Jason
Comparative genomics and transcriptomics in the mammalian fungal pathogen Coccidioides spp.

Coccidioides spp. are dimorphic fungal pathogens that cause the mammalian disease coccidioidomycosis, also known as San Joaquin Valley Fever - a potentially fatal infection that can occur in healthy human adults. C. immitis and C. posadasii are members of the Ascomycota, order Onygenales - a diverse group of fungi that includes both mammalian pathogens and non-pathogens. In the first chapter, full transcriptomes were sequenced for the hyphal and spherule growth phases for both C. immitis and C. posadasii. In the second chapter, the closest known relatives of Coccidioides spp. were sequenced for comparative phlyogenomics. In the third chapter, the origin of lineage- specific genes was assessed in Coccidioides. The work described here takes advantage of Illumina next generation sequencing technology to assess gene expression and genomic changes in Coccidioides that allow these species to form the complex spherule growth morphology. The techniques and experimental approach used are broadly applicable across all organisms; Coccidioides makes a particularly interesting case study, given the evolutionary conundrums in the Onygenales.

Advisor: Taylor, John W
Nanodiamond Imaging: a New Molecular Imaging Approach

Nanodiamond imaging is a novel biomedical imaging technique that non-invasively records the distribution of biologically-tagged nanodiamonds in vivo, in two or three dimensions. A nanodiamond imaging system optically detects electron spin resonance of nitrogen-vacancy centers in nanodiamonds, a non-toxic nanomaterial that is easily biologically functionalized. Two systems were built to demonstrate the feasibility of the technique. Using the first system, we imaged 2D projections of multiple nanodiamond targets within pieces of chicken breast; it is the first demonstration of imaging within scattering tissue by optically-detected magnetic resonance. The first system achieves a sensitivity equivalent to 740 pg of nanodiamond in 100 s of measurement time with a spatial resolution of 800 μm over a 1 cm2 field of view. The second system was built with a field of view large enough to image a mouse, and with the capability to acquire multiple 2D projections of the subject for 3D reconstruction of the nanodiamond distribution./nIn this thesis, we briefly review existing imaging modalities. We show how nanodiamond imaging has the potential to image with both high sensitivity AND high spatial resolution over organism-scale fields of view, features which are mutually exclusive in existing modalities (except at the shallowest imaging depths). Nanodiamond imaging's combination of high sensitivity and high resolution is potentially one of its greatest advantages. With reasonable sensitivity increases we expect to achieve a sensitivity of 100 fg and potentially as low as 25 ag; spatial resolution could reasonably be extended to <100 μm and is only limited by the strength of the magnetic gradient. We discuss practical ways to achieve these sensitivity increases, including various different modulation schemes./nWe also review the nitrogen-vacancy center and its optically-induced spin polarization and optical spin detection mechanisms starting from a group-theoretic understanding of its energy levels. We build upon knowledge of the nitrogen-vacancy center, starting from its spin Hamiltonian, to present a model of the optically-detected magnetic resonance lineshape of nitrogen-vacancy centers in nanodiamond powder. This model is compared to measurements. We explore the imaging point-spread function and show how imaging at just above the NV zero-field frequency--2.872 GHz, rather than 2.869 GHz--improves the contrast./nDetails of the imaging systems are discussed, including the stable source of optical excitation provided by band-pass-filtered LEDs, and the sensitive optical detection provided by custom-built photodiode amplifiers that were shielded to reject microwave interference. Other detailed subsystems designed and constructed for these imaging systems include electromagnet coils and multichannel bipolar magnet power supplies, and software for experiment control and signal processing.

Advisor: Yablonovitch, Eli
Mitigating Renewable Variability through Control and Optimization Techniques

Motivated by environmental and energy security concerns, many states and countries have enacted legislation calling for increased renewable adoption in the electricity sector. Unlike conventional fossil fuel-based electricity sources, renewable resources such as wind and solar power are characterized by intermittent, uncertain, and non-dispatchable output. Successfully addressing this variability in renewable generation is a prerequisite for deep renewable penetration. The prevailing paradigm in most power systems, exemplified by programs such as the Participant Intermittent Renewable Program (PIRP) in California, is one where the system operator accepts all renewable generation and absorbs the attendant variability through operating reserves. This approach works today at modest renewable generation levels but will result in untenable increases in reserve requirements tomorrow when renewables serve a sizeable fraction of total electric load. Hence, meeting ambitious renewable penetration targets will require the implementation of a number of variability mitigation strategies across the entire spectrum of power system operations. In this dissertation, we identify and explore areas in which control and optimization techniques can help provide some of these solutions./nOne such mitigation strategy is the coordinated aggregation of deferrable loads and storage, in which load is tailored to match variable supply. We investigate methods of exploiting these demand-side capabilities by developing and evaluating algorithms for the real-time scheduling of these flexible resources. We note that the benefits of coordinated aggregation can be achieved at modest levels of both deferrable load participation and flexibility. We also provide an analytical framework for understanding how these resources influence the costs of meeting load requirements incurred in wholesale electricity markets. Specifically, we explore the interplay between deferrable load scheduling and cost-minimizing procurements of bulk power and reserve capacity made in the day-ahead forward market./nAnother solution we consider, specific to wind power, involves curtailing generator output in certain situations. We explore how a wind power producer - subject to financial penalties for imbalances from contracted amounts - might leverage power curtailment capability to mitigate financial risk arising from price and production uncertainty. In particular, we analytically quantify the economic benefit derived from curtailment as an explicit function of expected prices, and compute empirical estimates of this curtailment benefit using price data from the various power system operators.

Advisor: Poolla, Kameshwar
A Team-Based Behavioral Economics Experiment on Smoking Cessation

Tobacco use is a leading cause of death worldwide, yet smoking cessation services are not widely available in many low-resource settings. Popular approaches also fail to help smokers to maintain self-control and motivation. The degree to which peer pressure promotes self-control in team-based health interventions remains largely untested. Moreover, peer pressure and cash incentives have rarely been mobilized in tandem. To this end, we conducted a randomized controlled trial in 42 villages in Thailand to test a novel intervention that combines commitment contracts for smoking cessation with team incentives that activate peer pressure. We randomly assigned 201 participants, 11% of all smokers in the study area, to a control group that received smoking cessation counseling or a treatment group that received counseling plus a commitment contract, team incentives, and text message reminders for smoking cessation. We find that, relative to the control group, the intervention increased biochemically verified smoking abstinence by 25% points at six months (three months post-intervention). Moreover, the intervention cost about $300 per marginal quitter, less than half that of common smoking cessation aids in Thailand. We find evidence that exogenously selected teammates had a large causal effect on each other's outcomes. The team effects are heterogeneous with respect to participants' ex ante quit predictions: the success of less confident smokers increases with a teammate's degree of self-confidence whereas the success of more confident smokers does not change. Further analyses indicate that heterogeneous teams result in higher aggregate quitting than do homogeneous teams. Our team commitment intervention may offer a viable cost-effective alternative to smoking cessation approaches in low-resource settings.

Advisor: Dow, William H
Static and Microwave Transport Properties of Aluminum Nanobridge Josephson Junctions

Josephson junctions are the basis of superconducting qubits, amplifiers, and magnetometers. Historically, tunnel-style junctions have been most common. However, for some applications--those requiring a small, highly transparent, all-superconducting junction--nanobridge weak link junctions may be preferable. This thesis presents extensive characterization of aluminum nanobridge Josephson junctions. The junction behavior is simulated by numerically solving the Usadel equations. These simulations are then tested and confirmed via low- and microwave-frequency transport measurements. The data confirm that nanobridge junctions approach the ideal weak-link Josephson limit./nSuch a near-ideal junction can be used in a superconducting quantum interference device (SQUID) to form an ultra sensitive magnetometer. This thesis presents the first nanobridge-based dispersive SQUID magnetometer. The devices show near-zero dissipation, with bandwidth and sensitivity on par with the best reported results for any SQUID-based magnetometer. These magnetometers have several flexible modes of operation, allowing for optimization of sensitivity, bandwidth, or backaction. They also provide insight into the internal dynamics of dispersive measurement with nonlinear cavities, as the magnetometer backaction depends on the bias point and can readily be measured./nNanobridge junctions also provide a useful tool for diagnosing sources of decoherence in superconducting qubits. By replacing the usual tunnel junction with a nanobridge, the contribution of the junction to decoherence processes may be probed. In particular, the interaction of nanobridge junctions with quasiparticles provides information both about the junctions themselves and about quasiparticle generation and relaxation mechanisms. This thesis reports measurements of nonequilibrium quasiparticles trapping in phase-biased nanobridge junctions. By probing the quasiparticle-induced changes in resonant frequency of a high-Q nanoSQUID oscillator, one may measure the mean distribution of trapped quasiparticles and study its temperature dependence. These measurements also provide spectroscopy of the junctions' internal Andreev states and the dynamics of quasiparticle excitation and retrapping. The work presented here demonstrates the utility of nanobridge junctions as a tool for quantifying the population and distribution of quasiparticles in a superconducting circuit.

Advisor: Siddiqi, Irfan
Parallel Layout Engines: Synthesis and Optimization of Tree Traversals

Mobile web browsers and data visualization tools require a performance boost. Parallelization poses an opportunity because commodity computers feature fast and energy-efficient multicore, subword-SIMD, and GPU hardware. However, layout engines in both browsers and visualizations have resisted parallelization thus far. This thesis introduces techniques for parallel computing over trees and applies them to generating layout engines./nOur solution is twofold. First, we show how to specify layout languages in the attribute grammar model of constraints over trees. Second, we address outstanding challenges in parallelizing attribute grammars and computations over trees. Our resulting attribute grammar compiler generates layout engines for various layout languages and parallel hardware./nWe provide several individual contributions:/n* We specify the functional and parallel behavior of common layout language primitives./n* We present a language for scheduling parallel tree traversals and a static verifier for ensuring a schedule will solve the attributes of an arbitrary layout in a safe order./n* We introduce a parallel programming model where programmers may partially specify the parallel schedule and call an optimizing synthesizer to complete the schedule./n* We design a scheduling algorithm that is fast and modular over scheduling constructs./n* We optimize tree traversals for SIMD hardware by automatically staging dynamic memory allocation and clustering diverging tasks./n* We optimize parallel tree traversals for MIMD architectures through a load-balancing heuristic that approximates work stealing./nTo evaluate our approach, we present two case studies. First, we generated the first parallel webpage layout engine that can for the most part render complex sites such as Wikipedia. Second, we generated interactive data visualizations that support up to 1,000,000 data points in real-time. Both case studies have been further validated industrially.

Advisor: Bodik, Rastislav
Of Gratitude and Sorrow: A Visual History of Everyday Mexican Spirituality, 1700-2013

This dissertation is a study of Mexican devotional images and their importance in the society that produced them. I trace the changes and continuities in the ways that Mexicans experienced the sacred over a long arc of history, with a focus on the nineteenth century, a time when Mexico transitioned from a colonial society into a modern republic. The study encompasses devotional practices such as pilgrimages and processions, but focuses especially on the material culture of popular piety. Specifically, it examines two art forms--ex-votos and children's funerary portraits--to show how devotional practice shaped relationships to the institutional church both before and after independence, as well as to the emergent liberal state in the nineteenth century. I use these images to explore the worldviews of people who left little in the way of written records, but whose visual output was both prolific and expressive of their perceptions about the relationship between humans and the divine./nThrough the study of the material culture of devotion, I demonstrate not only the continued centrality of Catholic holy beings to Mexican mentalities after independence, but also explore a changing world, one that we can loosely characterize as "modernizing." "Modernizing" was evident in several spheres: in the urban landscape, in transportation, in politics, the economy, in technology, and in the institutional church. In this context it is easy to imagine that forms of religious expression might also change, but traditional religiosity--with its processions, pilgrimages, and other saint-oriented devotional practices--not only survived but flourished in the nineteenth century. This particularly Catholic accommodation with modernity is most visible in an increase in ex-votos left at shrines, but also in the augmented negotiations over the proper role of religion in public life. I explore the reasons for these phenomena and conclude that despite the apparent paradox of continuing and increased "traditional" religious practices in a secularizing world, affirmations of traditional Catholicism were in fact a way of assimilating the modern world for both the institutional church and for laypeople./nFinally, I address the complex negotiations between the church and the state as political institutions from the colonial period to the mid-twentieth century, and the ways that their ideologies and actions both shaped and were shaped by popular culture. Using Mikhail Bakhtin's model of circularity for describing the interactions between elite and popular cultures, I look beyond simple dichotomies and suggest how the transmission of culture and ideas is multidirectional and multidimensional. I use visual cultural production--especially ex-voto paintings--as a barometer of religious mentalities, and, by extension, as a measure of the intersections between religion and politics in a period of important historical changes.

Advisor: Chowning, Margaret
Loop group actions on categories and Whittaker invariants

We develop some aspects of the theory of D-modules on schemes and indschemes of pro-finite type. These notions are used to define D-modules on (algebraic) loop groups and, consequently, actions of loop groups on DG categories. We also extend the Fourier-Deligne transform to Tate vector spaces./nLet N be the maximal unipotent subgroup of a reductive group G. For a non-degenerate character c of N((t)), and a category C acted upon by N((t)), there are two possible notions of the category of (N((t)),c)-objects: the invariant category and the coinvariant category. These are the Whittaker categories of C, which are in general not equiva- lent./nHowever, there is always a natural functor T from the coinvariant category to the invariant category. We conjecture that T is an equivalence, provided that the N((t))-action on C is the restriction of a G((t))-action./nWe prove this conjecture for G=GLn and show that the Whittaker categories can be obtained by taking invariants of C with respect to a very explicit pro-unipotent group subscheme (not indscheme) of G((t)).

Advisor: Teleman, Constantin