VictorJuiz/thesis huggingface dataset:
Oxide surface and bulk atomic structures studied by real space and reciprocal space probes [electronic resource]
Keywords: Materials Science and Engineering.

The versatile and intriguing properties of complex oxide materials make them important components of electronic, optical, electrochemical and catalytic devices and applications. However, the understanding of such materials is often constrained by our ability to characterize the oxide crystals in full details. One difficulty is to characterize the location and the fractions of transition metals with similar atomic numbers and radii in the bulk of multi-cation oxide systems whose properties are can be affected by the cation disorders. Another example is pertinent to surfaces on which important catalytic reactions take place between the oxide surfaces and the gas molecules in the surrounding environment. Many surface characterization techniques are electron based and limit their usage to unrealistic conditions (e.g. ultrahigh vacuum). Synchrotron X-ray radiation provides unique advantages for characterizing oxide materials, particularly its tunable energy and extremely large intensity. In this dissertation, I will demonstrate how we enable two diffraction techniques at the Stanford Synchrotron Radiation Lightsource to obtain important information about the bulk and surface atomic structure of materials. Specifically, in the first part, we employ the resonant diffraction to investigate the site-specific cation occupancies in the bulk A2BO4 spinel oxides. The quantification of the anti-site defect concentrations in materials such as Ga2ZnO4, Cr2MnO4, Co2NiO4, and Co2ZnO4 explains the electrical behaviors of several distinctive classes of spinels. The excellent agreement between experiment results and theoretical predictions validate doping rules in spinels. In the second part, I detail the refinement approach to model the atomic structure of oxide single crystals and thin films based on crystal truncation rods, diffuse scattering features that are sensitive to surface structures. Cerium dioxide (CeO2), an electrode material for fuel cells and electrolyzers, is grown commensurately on yttria-stabilized zirconia (YSZ) and the oxide heteroepitaxy is used as a model system for surface structural determination. The interface and surface roughness is investigated by surface X-ray diffraction at ambient pressure and at elevated temperatures. We show that the surface roughness has two components of different physical origins over different length scales. Combining other characterization performed on films of different thicknesses, we determine the growth mode transition of ceria ultrathin films induced by the large biaxial strain. We propose the dislocation formation mechanisms at the heterointerface of ceria and YSZ to explain why it is possible to grow commensurate ceria films beyond the critical thickness predicted by equilibrium theory. The model system of coherently strained ceria ultrathin films will enable us to study the interplay of strain, point defects, and the interface and their effect on transport and catalytic properties in heteroepitaxial oxide systems.
The "Paris school" of Russian poetry [electronic resource]
Keywords: Slavic Languages and Literatures.

The dissertation is dedicated to the literary phenomenon of the "Paris School of Russian Poetry." The author borrows this concept from a seminal article of André Warnod to describe the artistic activities of a group of young poets from different parts of the Russian Empire who emigrated to Paris and wrote in Russian. They exerted their biggest impact on the Russian culture and Russian literary life abroad in a very short period of time, between 1919 and the end of 1925. These young poets were close to the French avant-garde writers and artists, the representatives of Dada movement and Surrealism. They worked together with innovative painters from Montparnasse, wrote non-traditional poetry and published unconventional books. The author presents characteristic features of these poets, both as a group and individually, and creates a collective portrait of the "Paris School of Russian Poetry.".
Parodies of Paideia [electronic resource] : prose fiction and high learning in the Roman empire
Keywords: Classics.

This dissertation analyzes three works of ancient prose fiction, the Life of Aesop, the Story of Apollonius of Tyre, and the Alexander Romance, in order to determine whether prose fiction was a "popular" literary genre in antiquity and to illuminate how prose fiction engaged the "elite" authors of the classical canon. Investigating literacy rates, the economics of book production, and access to education in the Roman Empire, I argue against the existence of any popular literary texts in Imperial period and introduce a new paradigm of authorized and unauthorized cultures that derive their status from institutionalized cultural capital. Furthermore, I demonstrate that the "unauthorized" fictions of Aesop, Apollonius, and Alexander had a close and confrontational relationship with the "authorized" literature of the canon, especially the Greek and Latin authors at the center of the school curriculum. While classical scholarship often addresses how the most elite writers of the Greco-Roman world interpreted the classical tradition, this research reveals how similar negotiations with the canon took place in aspiring intellectual communities.
Part one: investigations of voltage-gated sodium channels in the central and peripheral nervous systems; Part two: carbocyclization of unsaturated thioesters under palladium catalysis [electronic resource]
Keywords: Chemistry.

Voltage-gated sodium channels (NaVs) are membrane-bound proteins responsible for the initiation of action potentials in electrically excitable cells. Naturally occurring guanidinium toxins, including (+)-saxitoxin (STX), target the outer pore of NaVs with remarkable selectivity and potency. Inspired by a growing interest to understand the role of NaVs in healthy and aberrant biological functioning in neurons, we have synthesized fluorescent analogues of STX and applied them to the visualization of NaVs in primary cell cultures and tissue. Of these fluorophores, STX-coumarin (STX-Cou) has distinguished itself for its potency and utility in live neurons; studies with STX-Cou in primary neuronal cultures represent the first reported imaging of NaVs in such cells. Our work to synthesize and evaluateSTX-Cou binding as well as to assess the utility of this fluorophore for selective NaV imaging in neurons through fluorescence microscopy is described herein. We have initiated efforts to study NaVs in the peripheral nervous system. Our work, conducted in collaboration with Prof. Ben Barres' lab (Dept. of Neurobiology), has revealed a form of NaV regulation in dorsal root ganglion neurons mediated by the surrounding glial cell network. The characterization of this interaction as well as key mechanistic insights are presented. Finally, inspired by the complex polycyclic architectures of STX and other guanidinium toxins, we have developed and introduced new synthetic strategies for the construction of carbo- and heterocycles from the appropriate linear precursors. In particular, we describe the palladium-catalyzed, copper- and zinc-mediated cyclization of thioesters with pendant olefins and alkynes to form the corresponding ketone products. This work offers new synthetic methods for the preparation of cycloalkanone compounds and also provides additional impetus for the continued discovery of methods for late-stage cyclization of acyclic molecules.
Parts in building construction projects [electronic resource] : definition and case study
Keywords: Civil and Environmental Engineering.

The Architecture, Engineering, and Construction (AEC) industry's productivity rate is lower than the manufacturing industry. One primary cause is the limitation in understanding of detailed input products. This thesis intends to help construction project teams apply successful manufacturing experience and manage construction projects from a basic input product point of view. It points out the importance of building parts and defines a part as "any entity that requires an act of installation to become a component in the final building product". This definition emphasizes the LEAN concept of value and focuses on on-site installations, which are direct value-adding activities. The author categorized parts into discrete and non-discrete parts to quantify parts and conducted a case study to estimate the number of parts in a seven-floor hotel. The result showed a range of 3.2 to 4.6 million parts with more than 90% of the parts not identified in Building Information Models (BIMs). This discrepancy makes it difficult for construction crews to plan and be efficient every day since they need the detailed information about the input products to ensure availability of all materials needed. This thesis points out that identifying and quantifying parts will help the AEC industry understand its projects and their parts. This knowledge of parts is also necessary in evaluating prefabrication benefits, or adopting manufacturing strategies such as LEAN for the production of detailed parts to improve productivity. In the next step, the author plans to study different part attributes, such as temporary work needed and part-related productivity data, to support construction teams using the parts concept in project management.
Patterns and symmetries for discourse particles [electronic resource]
Keywords: Linguistics.

Discourse particles provide important signals in conversation, by helping speakers and hearers coordinate on the course of an interaction. Therefore, a precise understanding of discourse particles will provide new insights into the pragmatics of conversation. In this thesis, I will present a framework based on questions under discussion that allows us to capture the key information-theoretic structures in conversation that seem to affect the use of discourse particles: the presence or absence of presuppositions, the issues guiding a conversation, and how interlocutors move between these issues. I present two case studies of German discourse particles that highlight central aspects of the QUD framework: überhaupt and doch. These raise a challenge found in particle systems in many languages: lexicalized focus. Many languages possess particles that can occur with or without focus, and the meanings associated with the unfocused and focused variants are often very different. Since intonation can have discourse-managing functions similar to that of discourse particles, the effect of having or lacking focus marking directly on a particle is different from the effect of focus on regular content words. I will identify patterns that allow us to systematically distinguish the meanings of focused and unfocused particles in a focused/unfocused pair. This serves as a stepping stone towards understanding the interplay of grammar, intonation, and interaction.
Performing shapes [electronic resource] : composing the gap between performer and image
Keywords: Theater and Performance Studies.

My dissertation is located within the field of performance phenomenology, with an emphasis on the practice of the performer. Examining the works of three contemporary artists in dance and theatre -- Claudia Contin Arlecchino, Virgilio Sieni, and Ann Carlson -- who make performance in conversation with visual arts, I focus on the phenomenon of the performer's gesture, or aesthetic movement, considering it as a bridge between performing arts and visual arts. By working on images, these artists establish a relationship between form and the act of perFORMing. The passage that I propose from the word performance to the word performing emphasizes the process of making as thinking -- that is, the role of the performer as the designer of her action and the perceiver of its processual phenomenon. Using images from distinct traditions to elaborate innovative techniques in acting and dancing, each of these artists presents a different approach to the image -- literal, structural, and reenacted -- and provides new methodologies for directing and choreography. Their practice, which I define as figural performing, constitutes an important subject of investigation for performance theory and phenomenology, for it locates the performer at the true center of thinking and making performance. Based on a formal use of the image, figural performing offers an alternative to methods of performing in dance and theatre based on the dramatic text or the body. My study's exploration of the figural builds on a minor lineage in need of further examination -- from commedia dell'arte and biomechanics, to Isadora Duncan and Oskar Schlemmer, to Happenings and action painting. By emphasizing gesture as a connection between performance and visual arts, my study also fosters an interdisciplinary analysis and historicization of performance.
Performing the politics of translation in modern Japan [electronic resource]
Keywords: East Asian Languages and Cultures.

This dissertation examines the ways in which translation, theater, and political activism interacted in Japan from the standpoint of two key opposition political movements between the Meiji Restoration in 1868 and the end of World War II. As such, it is an attempt to bridge gaps between fields of study represented by the diverse triad of theater, translation, and political theory. I seek to explain the importance of translation in the theatrical and political worlds of prewar Japan. Conventional scholarship on the modernization of Japanese theater usually tracks its development from within the theatrical world. By contrast, my approach explores politically charged performances in both traditional and non-traditional performance spaces in order to uncover the way their interaction influenced the formation and development of modern theater. I examine the influence of political, para-theatrical activity that involved translated texts and concepts in the context of the Freedom and People's Rights Movement of the 1870s and 1880s and the Proletarian Movement of the 1920s and 1930s.
PhaMers Identifies Novel Bacteriophage Sequences from Thermophilic Hot Springs
Keywords: Quake, Stephen
Bacteriophage
Phage
Metagenomics
Yellowstone
PhaMers
Thesis

Discovering novel phage sequences from metagenomic data is often challenging. This study presents PhaMers (Phage k-Mers), a phage identification tool that uses supervised learning to identify metagenomic sequences (contigs) as phage or non-phage on the basis of tetranucleotide frequencies. PhaMers compares the tetranucleotide frequencies of metagenomic contigs to those of phage and bacteria reference genomes from online databases. Using PhaMers, we identified 103 novel phage sequences in hot spring samples from Yellowstone National Park. We applied a microfluidic-based mini-metagenomic approach to sequence environmental samples and produce metagenomic sequence datasets. We analyzed assembled contigs using PhaMers and VirSorter, a publicly available phage identification and annotation pipeline. We present the performance of PhaMers in identifying genomic fragments of phages and its ability to predict phage taxonomic classification. We also present putative hosts and taxa for some novel phage sequences. PhaMers is available for public use at https://github.com/jondeaton/PhaMers.
Pharmaceutical Copay Assistance Programs and Patient Drug Choice: Biological Specialty Drugs
Keywords:  Department of Economics
Stanford Department of Economics
Tiered co-pay schemes
co-pay offset programs
prescription drug choice
pharmaceutical pricing
and coupons
Thesis

In an effort to manage prescription drug spending, health insurers design tiered copay schemes that steer patients towards buying lower-price drugs. In response, pharmaceutical companies issue coupons (called copay cards) that can lower the high co payments insurers assign to non-preferred drugs. This paper exploits the lifting of a ban on coupons in Massachusetts effective July 2012. The paper examines the effect of the ban lift on patients’ choice of drug brand as well as changes in the cost burden shared by insurers and patients. I use pharmacy claims data for biological specialty drugs that treat Multiple Sclerosis and Rheumatoid Arthritis to examine the effect of copay cards on insurers’ costs and patients’ purchasing behavior. I find that brand names that introduced coupons following the ban lift saw a 16% increase in the number of prescriptions (scripts) and patients per quarter relative to brand names that did not offer coupons. Moreover, I find evidence that the likelihood that a transaction had a coupon increases with the co payment. Lastly, I find that for a given drug brand, following the ban lift, transactions with a coupon also had higher co payments. This fact suggests that the introduction of coupons in Massachusetts was offset by a decrease in the share of the drug cost covered by the insurer, resulting in no change in the patient’s out-of pocket
payment.
Phase equilibria and emergent electromechanical coupling in two-dimensional materials [electronic resource]
Keywords: Materials Science and Engineering.

Two-dimensional monolayer crystals are a family of materials that exist in atomically thin form, lacking the chemical energy penalty associated with conventional surfaces. The first experimental isolation of two-dimensional crystals in 2005 triggered a wave of research, motivated by these ultra-thin materials' promising transport properties and their attractiveness as building blocks for atomic-scale heterostructure devices. Equally intriguing but hitherto largely unexplored device applications arise when the electronic state of a two-dimensional material interacts with non-electronic degrees of freedom. This dissertation elucidates several different instances of such coupling, along with their potential applications. First, this work discovers that that many commonly studied two-dimensional materials exhibit highly useful electromechanical coupling in the form of piezoelectricity, in contrast to their non-piezoelectric parent bulk crystals. Our density functional theory (DFT) calculations of the piezoelectric coefficients of monolayer BN, MoS2, MoSe2, MoTe2, WS2 and WSe2 reveal that some of these two-dimensional materials are more strongly piezoelectric than bulk wurtzites. Bilayers composed of two piezoelectric monolayers are then shown to possess leveraged coupling between mechanical curvature and electric fields - an emergent nanoscale property that occurs only in bilayers. The next part of this dissertation focuses on an anomalous form of electromechanical switching specific to Mo- and W-dichalcogenide monolayers. DFT calculations on these systems show that tensile strains can drive phase transitions between competing semiconducting and metallic two-dimensional crystal structures. Such strain-induced structural phase transitions occur at especially modest strains in MoTe2 (0.3-3.0% under uniaxial conditions). Finally, this work considers alloying between MoTe2 and WTe2 as a means of bringing monolayer phase transitions close to ambient conditions, for example to enable temperature-driven phase transitions near room temperature. Phase diagrams computed via DFT show that one can use the composition of alloyed monolayers to tune the relative stability of competing monolayer phases in such alloys.
Phase separation in BaPb1-xBixO3 and fermiology of hole-doped PbTe [electronic resource] : insights to understand superconductivity in valence-disproportionated systems
Keywords: Physics.

Valence disproportionated materials are an intriguing class of compounds in which ions of the same chemical element exist in two different states of oxidation. In this thesis, I have studied two anomalous superconductors that are based on materials that exhibit charge disproportionation. My experiments, which probe details of the crystal structure (via high resolution transmission electron microscopy) and of the electronic structure (via quantum oscillations), reveal key aspects of both systems that are associated with the superconductivity. In the case of the first system, the bismuthate BaPb1-xBixO3, we reveal a stripe-like nano-scale structural phase separation for superconducting compositions. This phase separation appears to be a key component in shaping the superconducting dome in this material, leading to a crossover from an inhomogeneous macroscopic superconductor to a granular superconductor for which phase fluctuations suppress Tc. Significantly, this observation implies that this material is intrinsically a higher temperature superconductor. The second family of materials studied in this PhD thesis is one resulting from hole doping in the narrow band gap semiconductor PbTe. The only impurity known to produce superconductivity in this host material is Tl, which has previously been tentatively associated with dynamic valence fluctuations of the Tl impurities. We performed a full Fermi surface characterization of Pb1-xTlxTe, as well as its non-superconducting analog, Pb1-xNaxTe, via Shubnikov de Haas oscillations in magnetotransport, for fields up to 35T (DC). Our results indicate the presence of incoherent resonant impurity levels for Tl concentrations beyond a critical value. The presence or absence of these states at or near the Fermi energy is intimately connected to the presence or absence of superconductivity in doped PbTe. We also show that the Fermi surface of these compounds, in the low temperature regime and for carriers concentrations up to 1x10^20cm^−3, is in fact simpler than has been previously thought, deriving from a single-non-parabolic band.
Phonon sensor dynamics for cryogenic dark matter search experiment [electronic resource] : a study of quasiparticle transport in aluminum coupled to tungsten transition edge sensors
Keywords: Physics.

Understanding the quasiparticle diffusion process inside sputtered aluminum (Al) thin films (∼ 0.1-1 μm) is critical for the Cryogenic Dark Matter Search (CDMS) experiment to further optimize its detectors to directly search for dark matter. An initial study with Al films was undertaken by our group ∼ 20 years ago, but some important questions were not answered at the time. This thesis can be considered a continuation of that critical study. The CDMS experiment utilizes high purity silicon and germanium crystals to simultaneously measure ionization and phonons created by particle interactions. In addition to describing some of the rich physics involved in simultaneously detecting ionization and phonons with a CDMS detector, this thesis focuses on the detailed physics of the phonon sensors themselves, which are patterned onto CDMS detector surfaces. CDMS detectors use thin sputtered Al films to collect phonon energy when it propagates to the surfaces of the detector crystals. The phonon energy breaks Cooper pairs and creates quasiparticles (qps). These qps diffuse until they get trapped in an proximitized "overlap" region where lower-Tc tungsten films connect to the Al film. These tungsten films are the transition edge sensors (W-TESs) CDMS uses to readout phonon signals. We performed a wide range of experiments using several sets of test devices de- signed and fabricated specifically for this work. The devices were used mostly to study quasiparticle (qp) transport in Al films and qp transmission through Al/W interfaces. The results of this work are being used to optimize the design of detectors for SuperCDMS SNOLAB.