VictorJuiz/thesis huggingface dataset:
Time- and Angle-resolved Photoemission Studies of Cuprate Superconductors

The origin of high-temperature superconductivity in cuprate ceramics is one of the great outstanding mysteries in physics. Discovered by Bednorz and Muller in 1986, the phenomenon has continued to both fascinate and baffle scientists for almost 30 years. At the heart of the cuprate problem lies the microscopic mechanism responsible for binding together Cooper pairs, which are a superconductor's lossless charge carriers. For most low-temperature superconductors, phonons are responsible, but Cooper pairs in the high- temperature superconductors may be bound together by magnetic interactions or even more exotic phenomena./nAlthough this most fundamental question remains unresolved, important insights continue to be gained in the field of high-temperature superconductivity, and many of them have originated from improved experimental methods and instrumentation. This thesis details progress in understanding the cuprate problem through the development and implementation of a high-resolution apparatus for conducting time- and angle-resolved photoemission spectroscopy (time-resolved ARPES). The technique works by using a near-infrared optical pump pulse to drive an electronic system out of equilibrium, and using an ultraviolet probe pulse to measure the subsequent dynamics of the nonequilibrium state using photoemission. Sub-picosecond time resolution is obtained by varying the path length of the pump pulse, and the net result is a movie of the relaxation dynamics of the band structure. Experimental results on the bi-layered cuprate superconductor Bi2212 are presented and discussed in detail./nContent is organized into eight chapters. Chapter 1 gives an introduction and overview of superconductivity research. Chapter 2 summarizes basic theoretical underpinnings of the ARPES technique, and reviews analysis techniques that are relevant to ARPES and time- resolved ARPES as well as simple models of quasiparticle recombination. Chapter 3 contains a detailed overview of the time-resolved ARPES system constructed in the Lanzara research group. Chapters 4, 5, 6, and 7 present scientific results obtained using time-resolved ARPES to study Bi2212. Finally, conclusions and future directions are discussed in Chapter 8.

Advisor: Lanzara, Alessandra
Política y estética del fraude en el modernismo latinoamericano: escritura, canibalismo y pedrería en Azul...de Rubén Darío

This dissertation draws on colonial texts in order to expand the critical corpus of Azul, beyond its conventional binary readings, either exclusively aesthetic or primarily Marxist, to render a vision of Rubén Darío that includes an account of Latin America as a space of criticism and transgression that challenges fixed notions of national identity, historical contexts, and authenticity in art. Expanding on definitions of fraud, this project develops the concept of fraude as a theoretical framework to show how Darío aesthetically constructs a writing which is deceptively apolitical. By fraude, I illustrate the form in which Darío appropriates and inhabits European identities and their spaces in order to invert the colonial violence historically inflicted in Latin America. Far from l&rsquoart pour l&rsquoart figure that is still so prevalent in the criticism ofAzul, the fraude, once decoded, reveals Darío as a poet whose writing opposes the empires of Spain, England, and the United States./nBy reexamining the colonial discourse-- in relation to sculpture, cannibalism and precious stones--, my research exposes the colonial texts, designed to appropriate and exploit the &ldquoother,&rdquo as an act of fraud in and of itself. Thus, Darío&rsquos writing, in reversing the colonial fraud, acquires a "hidden" political significance. To engage the colonial discourse within a modern nineteenth-century perspective also establishes new ground for reinterpreting the politics behind the works of Modernismo authors, such as José Martí and José Enrique Rodó with whom this dissertation is in conversation. From this viewpoint, the literary texts are to be understood as socially symbolic acts that aesthetically question and undermine dominant narratives. Even in the twenty-first century, when the global markets more than ever mediate and displace historical occurrences through the use of technology in visual mass media, blurring the boundaries between falseness and authenticity, an evaluation of fraude as a strategy for analyzing and questioning our social "reality" is necessary. This project places Modernismo in conversation with Transnational American and Postcolonial Studies by investigating how people, through shared colonial histories (still relevant in our present time), aesthetically negotiate their legacy.

Advisor: del Valle, Ivonne
Rosa, Richard
Strong Well-foundedness and the Genericity of Countable Sets

In support of the Inner Model Program, we establish that a strengthening of well-foundedness, strong well-foundedness, holds for models constructed with iteration trees of certain important types. We subsequently find instances in which this property implies that every countable subset of a model is generic over the model, thereby proving instances of the Genericity Hypothesis. We also place the property of strong well-foundedness in context by proposing how it could be used to establish iterability, a key concept of the Inner Model Program, via a new route.

Advisor: Woodin, William H.
Law, Land, and Territories: The Roman Diaspora and the Making of Provincial Administration

This dissertation examines the relationship between the institutions of Roman provincial administration and the economy of the Roman imperial diaspora in the Eastern Mediterranean in the second and first centuries BC. Focusing on the landed estates that many members of the imperial diaspora acquired in the territories of Greek cities, I argue that contestation over the allocation of resources in the provinces among Roman governing classes, the members of the imperial diaspora, and the elites of Greek cities decisively shaped the contours of what we would late recognize as the institutions of provincial administration./nSetting the Roman Empire within a new comparative framework, Chapter One suggests that ancient cities around the Mediterranean, including Rome, often used their imperial power to help their own citizens infringe upon the exclusionary property regimes of other cities, which insisted that--unless they decided otherwise--only their own citizens could acquire this land. Chapter Two combines semantic history with archaeological case-studies to argue that Roman ownership of agricultural resources in the territories of provincial cities was wide-spread and in fact often underpinned the movement of products for which the members of the diaspora are more commonly known. Chapter Three uses epigraphic documentation and Cicero's writings to examine how provincial governors responded to the economic concerns that Romans brought before them, maintaining that law became the most prominent response because it was able to perform a separation between the empire as state and the potentially problematic actions by members of the diaspora, while at the same time not abandoning these Romans' concerns. Chapter Four investigates the contestation over the terms on which members of the diaspora were able to acquire land in Greek cities and vindicates the contributions that Roman jurists and the elites of Greek cities made to the institutional architecture of provincial administration and the political economy it enshrined.

Advisor: Mackil, Emily
The Development and Validation of a Tactile Processing Speed Measure

Processing speed refers to the cognitive ability that is involved in fluently performing cognitive tasks with simple stimuli. Individual differences in processing speed can predict performance on tests of complex cognitive functions such as memory and fluid reasoning, as well as performance on academic tests in reading, writing, and mathematics. For this reason, measures of processing speed are included in most cognitive assessment batteries. However, extant measures of processing speed rely on visual stimuli, making them inaccessible to individuals with visual impairments. The current study describes the adaptation of one of the most commonly used processing speed measures, WISC-IV Coding, into a tactile task. Using a sample of 19 high school students (Mage = 15.74) with visual impairments who use braille as their primary literacy medium, have no additional disabilities, and are on track to receive their high school diploma by age 22, preliminary validation analyses were conducted. Split-half reliability calculations showed that scores on the instrument were reliable (a = .92). Additional instruments were administered - including the KeyMath-R braille adaptation, DIBELS braille reading fluency, and the Blind Learning Aptitude Test - to examine convergent and discriminant validity, and results provided evidence of convergent validity. Implications for practice and future directions for research are discussed.

Advisor: Worrell, Frank C
The Role of Conformational Energetics in Ligand Binding and Thermal Sensation

A major outstanding question in protein science is how different regions of a protein communicate with one another. Although we can identify action-at-a-distance phenomena when they occur, a generalized mechanism and an understanding sufficiently thorough as to allow for de novo design remain works in progress. This is particularly true for natively disordered proteins and channel proteins, both of which have traditionally been more technically difficult to characterize biophysically. In this work, I explore the functional relevance of their unique energetics and dynamics./nThe first project investigates the functional relevance of the hydrophobic core of disordered transcription factor MarA. We randomized the MarA hydrophobic core and selected for variants able to bind the consensus sequence. We find that MarA is highly intolerant of core mutation; this is in contrast to what is seen for the well-folded transcription factor λ-repressor. Furthermore, core variants that do retain the ability to bind consensus sequence have differentially altered affinities for different binding partners. We propose that this can be explained by taking into account the varying energetic impact of these mutations on different MarA conformations and posit that residues distant from the active site can alter both binding affinity and specificity in natively disordered proteins./nThe second project aims to shed light on the mechanisms of thermosensation. Protein channel TRPA is a heat sensor in rattlesnakes but exhibits no heat-dependent activation in mammals. This discrepancy was mapped to select ankyrin repeats within the protein's cytoplasmic N-terminal domain. We hypothesized that temperature-dependent conformational changes within these repeats propagated to the pore region may be the thermosensing mechanism employed by TRPA1. The isolated repeats were purified and analyzed biophysically. Rattlesnake ankyrin repeats 3-8 are unique in that they do not appear to unfold with temperature on the timescale tested. The mechanism of this remarkable thermotolerance and its physiological relevance are currently under investigation.

Advisor: Marqusee, Susan
Multidimensional Ultrafast Spectroscopy of Photosynthetic Pigment-Protein Complexes

This dissertation presents the application of ultrafast spectroscopy to the investigation of pigment-protein complexes (PPCs) involved in energy transfer and energy dissipation in photosynthetic organisms. PPCs are the building blocks of all photosynthetic organisms, and within individual pigment-protein complexes, energy transfer dynamics occur over fast timescales and broad spectral regions. Chapter 1 gives an introduction to the capability of photosynthetic organisms to absorb light energy, funnel this energy to a location for charge separation, and perform charge separation with subsequent conversion into chemical energy. All of these functions need to be performed efficiently under different light conditions. This chapter also includes a discussion of the different light harvesting strategies that various photosynthetic organisms have evolved. Lastly, this chapter discusses the application of ultrafast spectroscopy as an excellent tool to study the dynamics of PPCs. The three experimental techniques used in this dissertation are introduced in this chapter./nChapters 2 and 3 present the application of two ultrafast spectroscopic techniques, two dimensional electronic spectroscopy and transient absorption spectroscopy, to the investigation of the structure-function relationship of photosynthetic pigment-protein complexes. Chapter 2 is an investigation of the photophysics of the two forms of the Orange Carotenoid Protein, involved in excess energy dissipation in cyanobacteria. Ultrafast spectroscopy allows us to understand how a conformational change that modifies pigment-protein interactions is able to generate a different biological function. Chapter 3 presents degenerate and non-degenerate two dimensional electronic spectroscopy experiments to investigate the energy transfer dynamics and couplings in the bacterial reaction center, which is the location of charge separation./nChapter 4 investigates a PPC involved in excess energy dissipation in green algae, LhcSR. Fluorescence lifetime spectroscopy is used to investigate the excited state properties of LhcSR, which plays a role as light harvester, pH sensor and quencher in algae. The results allow us to identify two conformations, a light harvesting one and a quenching one. Transient absorption spectroscopy is used to investigate the energy transfer pathways involved in quenching in the two different conformations. Finally, Chapter 5 presents conclusions and extensions to future work, in order to improve our understanding of the energy transfer dynamics in natural photosynthetic systems.

Advisor: Fleming, Graham
Exploring Graphene Nanoribbons Using Scanning Probe Microscopy and Spectroscopy

Graphene nanoribbons (GNRs) are strips of graphene, featuring narrow widths at the nanometer scale. A GNR may be considered as a structure cut out of graphene, which is a two dimensional honeycomb lattice of sp2 carbon atoms. Cutting graphene in different ways may be understood as imposing different boundary conditions on graphene, and therefore the electronic structures of GNRs are dependent on their geometries. Fascinating properties of graphene nanoribbons ranging from width-dependent semiconducting energy gaps to localized edge magnetization are predicted in theory. These properties, together with their ultra-thin nature, give GNRs great potential in future electronic applications. This dissertation focuses on the fundamental relations between the geometry and the electronic structure of GNRs, and explores bottom-up strategies to synthesize GNRs via molecular self-assembly./nUsing scanning tunneling microscopy (STM) and spectrocopy (STS), chiral and ultra-narrow armchair GNRs and width-modulated GNR heterojunctions were studied. The localized edge states in chiral GNRs derived from unzipping carbon nanotubes were explored and evidence is shown that these states are spin-polarized. We further modified the chiral GNR edges with hydrogen plasma, and determined both the terminal hydrogen-bonding structure and the edge electronic structure by combining STM and ab initio simulation. Bandgap tuning of bottom-up synthesized armchair GNRs was demonstrated via development of a new molecular building block. We find that the energy gap of wider N = 13 armchair GNRs is 1.4 ± 0.1 eV, 1.2 eV smaller than the bandgap of a narrower N = 7 armchair GNR. In addition, width-modulated GNR heterojunctions were obtained by fusing segments of two different molecular building blocks, and were characterized to possess electronic structure similar to type I semiconductor junctions./nAs an effort to develop an alternative route toward synthesis of GNRs, we imaged and studied single-molecule enediyne chemical reactions on metallic surfaces with non-contact atomic force microscopy (nc-AFM). This bond-resolved imaging technique allows us to extract an unparalleled insight into the chemistry involved in complex enediyne cyclization cascades on surfaces.

Advisor: Crommie, Michael F
Essays on Mass-Participatory Finance Capitalism in the United States

This dissertation examines three interrelated questions about the patterns, causes, and consequences of mass-participatory financial activity in the United States during the years leading up to the 2008 financial crisis. The first chapter examines the economic geography of speculative investment during the mid-2000s housing bubble. Here I utilize Home Mortgage Disclosure Act data to test hypotheses about the community-level correlates of non-occupant housing purchase rates across U.S. counties. The second chapter takes up the question of why household indebtedness in the U.S. doubled from 1989-2007? I assess the empirical implications of alternative theoretical accounts using household-level data from the Survey of Consumer Finances. The third chapter addresses social stratification within mass-participatory investment markets by analyzing racial disparities in timing of entrance into the housing bubble. I use data from the Panel Study of Income Dynamics to assess the mechanisms that account for minorities' heightened likelihood of purchasing a house during the later years of the bubble. Together, the analyses contribute to sociological understandings of mass-participatory finance. They also draw new theoretical connections between the economic sociology of finance, stratification, urban sociology, and behavioral economics.

Advisor: Fligstein, Neil
A NEW LASER COOLING METHOD FOR LITHIUM ATOM INTERFEROMETRY

An atom interferometer offers means to measure physical constants and physical quantities with a high precision, with relatively low cost and convenience as a table-top experiment. A precision measurement of a gravitational acceleration can test fundamental physics concepts such as Einstein equivalence principle (EEP). We identified that the two lithium isotopes (${}^{7}$Li and ${}^{6}$Li) have an advantage for the test of EEP, according to the standard model extension (SME). We aim to build the world's first lithium atom interferometer and test the Einstein equivalence principle.\/nWe demonstrate a new laser cooling method suitable for a lithium atom interferometer. Although lithium is often used in ultra-cold atom experiments for its interesting physical properties and measurement feasibility, it is more difficult to laser cool lithium than other alkali atoms due to its unresolved hyperfine states, light mass (large recoil velocity) and high temperature from the oven. Typically, standard laser cooling techniques such as Zeeman slowers and magneto-optical traps are used to cool lithium atoms to about 1 mK, and the evaporative cooling method is used to cool lithium atoms to a few $\mu$K for Bose-Einstein condensate (BEC) experiments. However, for the atom interferometry purpose, the evaporative cooling method is not ideal for several reasons: First, its cooling efficiency is so low (0.01 \% or less) that typically only $10^4-10^5$ atoms are left after cooling when one begins with $10^9$ atoms. More atoms in an atom interferometer are needed to have a better signal to noise ratio. Second, an evaporative cooling is used to make a BEC, but we do not need a BEC to make an atom interferometer. In an atom interferometer, a high density of atoms as in a BEC should be avoided since it causes a phase shift due to atom interactions. Third, a setup for an evaporative cooling requires intricate RF generating coils or a high power laser. \/nWith a simple optical lattice and a moderate laser power (100 mW), we achieved a sub-Doppler cooling of lithium by a new laser cooling method despite the fact that lithium has un-resolved hyperfine structure. We identified that the Sisyphus cooling and the adiabatic cooling mechanisms cooperate and give both lower temperature and higher cooling efficiency than the result that can be achieved by each alone. We cooled ${}^{7}$Li atoms to $\sim \;50\;\mu$K (about 8 times the recoil temperature) in a one dimensional lattice with cooling efficiency of $50\%$. In three dimensions the cooling temperature was limited to $90\,\mu$K due to instability of our 3D lattice, however the same principle applies and potentially a lower temperature can be achieved in 3D as well.

Advisor: Mueller, Holger
Modeling Heat Transfer, Combustion, and Pollutant Transport within a Cook Stove and in a Room

Over half of the world's population, approximately 3 billion people, rely on biomass fuels (wood, charcoal, dung, and agricultural residues) and liquid fuels such as kerosene in cook stoves to meet basic needs for cooking and heating. Most cook stoves in use operate indoors without sufficient ventilation, have low efficiencies, and produce products of incomplete combustion. Indoor air pollution of toxic gases and soot aerosols from household energy use in developing countries cause health problems for families, disproportionately affects women and children, and in aggregate, has significant effects on public health. Additionally, aggregate emissions of black carbon and greenhouse gases from the combustion of household fuels in cook stoves adversely affect the environment and pose a serious threat to global climate change./nThis work looks at two components of household energy use in developing countries: 1) cook stove technology, and 2) assessing indoor concentrations of pollutants to determine personal exposure for public health. In this dissertation, the formulation of two computational fluid dynamics (CFD) models of the heat transfer, buoyant turbulent fluid flow, and combustion within a cook stove is described. Then, a model for indoor concentrations of pollutants in a room is described, and the model is applied to questions relevant to indoor air pollution and public health.

Advisor: Fernandez-Pello, A. Carlos