VictorJuiz/thesis huggingface dataset:
Multiscale modeling and testing of biopolymer-bound soil composites

Extraterrestrial construction presents many interesting and new challenges. Unlike Earth, in extraterrestrial environments, such as the moon or Mars, there are limited, naturally-occurring, resources that are readily available for construction purposes. Transporting large amounts of materials from Earth is cost prohibitive. This work focuses on the development of a novel class of composites for use in limited resource environments: Biopolymer-bound Soil Composites (BSC). The composite is produced by mixing soil, water, and a biopolymer binder to create a versatile composite with compressive strength comparable to that of ordinary Portland cement concrete (upwards of 40 MPa). This dissertation introduces a multi-scale framework to model and test the composite's mechanical properties for the purpose of robust design of BSC materials that can resist extreme environments. At the nanoscale, nanoindentation is used to obtain the mechanical properties of the dry biopolymer after dissolving in water and desiccating. At the microscale, the creation of Statistically Equivalent Periodic Unit Cells based on microCT images captures the spatial arrangement of soil particles, desiccated biopolymer and voids. Finite element modeling is then used to obtain basic mechanical parameters. At the mesoscale, a Rigid Body Spring Method (RBSM) model is used to simulate fracture using the homogenized properties obtained at the microscale. At the macroscale, triaxial testing and uniaxial tests aided by digital image correlation (DIC) are used to corroborate and tune the simulations. The goal of this dissertation is to devise a framework to support robust computational simulations that enable the prediction of the mechanical properties of BSC materials with different biopolymer-soil combinations. These new BSC materials can then be used in the design of future structures on the Moon, Mars or other celestial bodies. This work represents the first steps towards a comprehensive framework for computational modeling of BSC materials

Advisor: Lepech Michael 
Borja Ronaldo I. (Ronaldo Israel)
Loftus David
Myeloid reprogramming B cell acute lymphoblastic leukemia

Five-year survival rates for adult B-cell acute lymphoblastic leukemia (B-ALL) remain dismal, and novel approaches will be required to improve outcomes. I enumerate several important advances in a promising treatment strategy that entails reprogramming malignant B-cell precursors to macrophage-like cells. We found that primary human BCR-ABL1+ B-ALL cells could be induced to reprogram into macrophage-like cells by exposure to myeloid differentiation-promoting cytokines in vitro or by transient expression of the myeloid transcription factors C/EBPα or PU.1. The resultant cells were clonally related to the primary leukemic blasts but resembled normal macrophages in appearance, immunophenotype, gene expression, and function. Critically, reprogramming patient leukemic blasts to myeloid cells ablates their tumorigenicity in immunocompromised mice. We further determined that myeloid reprogramming may occur to some degree in human patients by identifying primary CD14+ monocytes/macrophages in BCR-ABL1+ B-ALL patient samples that possess the BCR-ABL1+ translocation and clonally recombined VDJ regions. Additionally, we found that small molecule drugs augment C/EBPα-driven myeloid reprogramming. We employed a whole genome CRISPR-Cas9 screen and identified genetic knockouts that improve reprogramming in a human cell line model of B-ALL. We validated two targets, EHMT2 and EHMT1, resulting from this screen for their ability to increase myeloid reprogramming. These genes encode protein products G9a and GLP, respectively, which form a heteroduplex capable of conferring the transcriptionally repressive histone mark H3K9me2. Ablating G9a expression, and subsequently H3K9me2 deposition in chromatin, speeds the transition of cells from a lymphoid to a myeloid state. The addition of A366, a small molecule inhibitor of G9a, induced higher frequency and more rapid myeloid reprogramming. Last, we found that the addition of A366 improved chromatin access measured by ATAC-seq at a number of important myeloid loci. The use of a small molecule in myeloid reprogramming is an important proof of principle for the clinical feasibility of reprogramming technology for hematologic malignancy. We built upon the principles of cell reprogramming, developing a new cytokine-dependent method of myeloid reprogramming, and discovering a novel small molecule target that improves myeloid reprogramming

Advisor: Majeti Ravindra
Alizadeh Ash
Levy Ronald
Winslow Monte
Naming and un-naming in Old English literature

Personal names, particularly historical ones, have long been subject to the unconscious biases of the modern scholars who study them. As a result, existing studies of Old English names have focused primarily on onomastic functions that are readily legible for modern readers, treating names as inter- and extratextual links, purveyors of etymological resonances, and, above all, referential labels for characters. In contrast, this dissertation investigates the ways in which the early medieval English experience of naming might diverge from modern expectations, using case studies and close textual analysis to explore what it means to read an Old English name—or any name—on its own terms. In the process, these case studies reveal a persistent anxiety about names that fail to perform their functions, a failure that leads to an utter onomastic negation discussed here as "un-naming." Chapters 1 and 2 are dedicated to Beowulf, the most well-studied Old English text and also one of the most onomastically dense. Chapter 1 challenges the assumption that names function primarily in a referential way, arguing that each instance of naming in this poem also becomes a means of signaling connection in its own right. Shifting to examine connectedness at the level of character, Chapter 2 recasts Beowulf's network of names as a means of controlling and containing anonymity, a measure that fails spectacularly when the anonymous, unconnected—and therefore un-named—dragon endangers not only the named social network within the poem, but also the audience outside of it. Chapter 3 explores the grammar of "being" and "calling" names in the Old English language, investigating the literary consequences of these naming strategies in a number of poems in the Exeter Book. While the "called" solutions of the Exeter Book Riddles help to construct the sense that an object inhabits its own proper place in the world, the prospect of "being" the names and pseudo-names in Deor, Wulf and Eadwacer, Widsith, and The Wanderer can lead to a horrifically indefinite, un-named existence. Finally, Chapter 4 argues that the names of the eponymous interlocutors of the Solomon and Saturn dialogue tradition act as a way of framing, authorizing, and otherwise containing the texts' "transgressive" qualities—a containment that ultimately shatters in Solomon and Saturn II when the monumental "Solomon" and "Saturn" who frame and authorize this dialogue split from the "Solomon" and "Saturn" who address each other as individuals. Together, these case studies demonstrate the stakes and consequences of naming in Old English literature, while also providing a model for more self-conscious and more deeply-contextualized inquiry into the meaning and function of literary personal names

Advisor: Treharne Elaine
Algee-Hewitt Mark
Starkey Kathryn
NanoLog : a nanosecond scale logging system

Instrumentation is fundamental to developing and maintaining applications in the modern datacenter. It affords visibility into what an application is doing at runtime, and it helps pin-point bugs in a system by exposing the steps that lead to an error. The most common method of instrumentation today is logging, or printing out human-readable messages during an application's execution. Unfortunately, as applications have evolved to become increasingly more performant with tighter latency requirements, traditional logging systems have not kept up. As a result, the cost of producing human-readable log messages is becoming prohibitively expensive. NanoLog is a nanosecond scale logging system that's 1-2 orders of magnitude faster than existing logging systems such as Log4j2, spdlog, Boost log, or Event Tracing for Windows. The system achieves a throughput of up to 82 million log messages per second for simple log messages and has a typical log invocation overhead of 8 nanoseconds. For comparison, other modern logging applications today can only achieve up to a few million log messages per second at log latencies of hundreds of nanoseconds to several microseconds. NanoLog achieves its ultra-low latency and high throughput by shifting work out of the runtime hot-path and into the compilation and post-execution phases of the application. More specifically, it performs compile-time extraction of static information from the log messages to reduce I/O and decouples formatting of the log messages from the runtime application by deferring it until after execution. The result is an optimized runtime that only outputs the minimal amount of data and produces a compact, binary log file. The binary log file is also amenable to log analytics engines; it is small relative to full, human-readable log messages and contains all the data in a binary format, saving the engine from parsing ASCII text. With these enhancements, NanoLog enables nanosecond scale logging and hopes to fill the performance gap left between traditional logging systems of today and the next generation applications of tomorrow

Advisor: Ousterhout John K. 
Rosenblum Mendel 
Zaharia Matei
Nanophotonic platforms for enhanced chiral light-matter interactions

Chiral, or "handed, " structures range from spiral galaxies to human hands to amino acids to circularly polarized light (CPL). The differential absorption between right and left CPL, known as circular dichroism (CD), is critical to applications spanning the synthesis and purification of pharmaceuticals and agrochemicals to all-optical magnetic writing and recording. However, differential absorption of CPL is generally up to five orders of magnitude below the absorption of unpolarized light. Recent advances in nanophotonics, the study and manipulation of light at the nanoscale, lay the foundation toward highly sensitive and efficient CD. In this thesis, I will describe progress we have made to leverage these nanoscale chiral light-matter interactions in molecular and magnetic systems using high-refractive index periodic nanostructures, known as metasurfaces. First, we computationally design a platform based on dielectric nanodisks that enhances the local optical chirality density by engineering the coupling between electric and magnetic optical resonances. These high-index dielectric nanoparticles can enable large-volume and uniform-sign enhancements in the optical chirality density. By overlapping electric and magnetic resonances, local chiral fields can be enhanced by several orders of magnitude. We show how these design rules can enable high-yield enantioselective photochemistry and project a 2000-fold improvement in the yield of a photoionization reaction. Next, I will discuss an experimental demonstration of metasurface-enhanced circular dichroism with a molecular monolayer. We fabricate silicon nanodisk metasurfaces and functionalize them with a self-assembled monolayer of dye-DNA complexes. We measure the monolayer fluorescence-detected circular dichroism in a home-built table-top polarization sensitive spectrometer; we also show how this technique is sensitive to changes in the CD handedness through double-stranded to single-stranded DNA denaturing. Finally, we extend this platform for use in all-optical information storage applications using magnetic materials. We show that the presence of helicity-preserving silicon nanodisks can enhance reflection and transmission dissymmetries under right- and left-CPL excitation, leading to higher differential local absorption and thus the potential to decrease power thresholds and miniaturize components in magnetic switching

Keywords: Materials Science and Engineering.
Advisor: Dionne Jennifer Anne
Brongersma Mark L.
Lindenberg Aaron Michael
Nanophotonic thermal, plasmonic and non-hermitian media : from fundamental limits to applications

Optics and photonics play a central role in modern science and technology, spanning renewable energy, fundamental science, consumer technology, sensors, therapeutics and medicine, global communication and information processing pipelines, and exciting new frontiers in quantum computing and artificial intelligence. Despite their vast diversity, these applications are threaded by electromagnetism, thermodynamics and quantum mechanics. In this Thesis, we begin at the intersection of thermodynamics and electromagnetism, exploring the fundamental limits of renewable energy harvesting technologies utilizing the Sun and the vast, cold outer space as thermodynamic resources. Then, making a connection to nanophotonics, we consider how nanostructuring affects the efficiency of energy harvesters such as solar cells, developing a rigorous mathematical formalism to treat light trapping. Continuing in the vein of the thermodynamics of photonic devices, we then develop a novel optical refrigeration mechanism that arises from tailoring the thermal radiation from active photonic structures. Next, we explore the behavior of plasmonic systems in a novel regime, demonstrating the significance of quantum-plasmonic effects in preserving their thermodynamic validity. Lastly, we explore a novel class of active electromagnetic media that break Lorentz reciprocity, finding applications in information processing schemes

Keywords: Electrical Engineering.
Advisor: Fan Shanhui
Brongersma Mark L.
Miller D. A. B.
Nanoscale electrical and thermal interfaces to resistive memory devices

Future computing systems need ultra-high storage densities for large volumes of data. Non-volatile resistive random-access memory (RRAM) based on metal oxides or phase-change materials could enable such high capacity with low latency. However, as memory cell dimensions are reduced to sub-10 nm scale, their contacts, interfaces, and self-heating can determine the memory device behavior and packing density, yet these are poorly understood. In the first half of my thesis, I will show that the electrical contact resistivity varies over 10 orders of magnitude depending on the memory material considered; cubic Ge2Sb2Te5 has contact resistivity near 10 mΩ⋅cm2 while contact resistivity to as-deposited HfO2 is as high as 0.5 MΩ⋅cm2, at room temperature. I will then showcase switching measurements on nanoscale memory devices and insights gleaned about the role of contact resistance. In the second half of my thesis, I will demonstrate some of the first nanoscale thermal measurements on resistive memory devices using scanning thermal microscopy. With a single-layer graphene as a top electrode, I show the most thermally intimate measurement of an RRAM filament to date and observe a device temperature rise > 300°C. Varying the thermal conductivity of electrodes over a 50x range, I investigate device-level heat spreading and conclude that Joule heating in a sub-10 nm filament can cause a temperature rise up to 200°C, even at a distance of 50 nm from a typical RRAM device. By comparison to simulations, I show that the filament itself can reach temperatures in excess of 1200°C within its hourglass-like sub-10 nm dimension geometry. This filament temperature strongly depends on the thermal boundary resistance at the filament-electrode interfaces. These novel insights point to the importance of nanoscale thermal engineering of the filament-electrode interfaces and of the electrodes to minimize array level thermal cross-talk and to enable ultra-high storage densities

Keywords: Electrical Engineering.
Advisor: Pop Eric 
Saraswat Krishna 
Wong Hon-Sum Philip
Nations by the Numbers: Ethnoracial Data Collection and National Identity in the United States and France

The question of how large, multicultural democracies balance diversity and national identity is crucial in an age in which these countries are both continuously diversifying and witnessing a surge in xenophobic nationalism. The politics of data collection exists at the heart of this tension, as quantifying people based on race, ethnicity, or religion can imply government legitimation of social divisions. In the United States, counting citizens by race and ethnicity is extremely common, yet this same practice is forbidden by law in France. From the French perspective, ethnoracial census categories serve to advance group-oriented rhetoric and undermine a unified French national identity. The motivation for my research is to test this claim — does government collection of ethnoracial data have adverse effects on the coherence and strength of national identity? In addition to analyzing the history of ethnoracial data collection in the United States and France, I conduct a national survey experiment of Americans assessing how ethnoracial categorization impacts respondents’ feelings of national identity. Ultimately, I find that ethnoracial categorization influences the national identification of white and black Americans, an effect that I posit stems from a relationship between Americanness and whiteness.

Keywords: Program in International Relations
race
census
social identity
Thesis
Advisor: Davenport Lauren
Natural image processing in the primate retina

The retina is the first stage of the visual system, where light is absorbed and encoded in the spikes of neurons. Information from roughly 100 million photoreceptors is compressed to the outputs of roughly 1 million neurons, called retinal ganglion cells, that make up the optic nerve. This is the brain's only source of visual information, yet how the retina uses this limited bandwidth is not well understood. This is particularly true for natural vision in primates, despite its relevance for human health applications, as retinal research is primarily done in non-primate species using targeted, artificial stimuli. Here, large-scale, multi-electrode recordings are used to investigate natural image processing in the primate retina through the complementary lenses of encoding, where computational models are used to predict the responses of RGCs to natural stimuli, and decoding, or reconstruction, where the stimulus is estimated from the RGC responses

Keywords: Physics.
Advisor: Chichilnisky E. J.
Schleier-Smith Monika
Baccus Stephen A.
Navigating climate change : he role of politics in youth discourse and scientific reasoning

Human-driven climate change remains divisive in the US, where skepticism of the scientific consensus is associated with political conservativeness. However, how politics affect youth perceptions of climate change has been studied only minimally. This dissertation deepens our understanding of the ways in which political views influence US youths' scientific reasoning about climate change. Study #1 used mixed methods to analyze the results of an individually randomized trial involving 357 participants in grades 9-11. Findings demonstrated the value of teaching mechanistic understandings of climate change, yet also showed the influence of worldview on receptivity to climate change for adolescents, as well as complex interactions between quantitative reasoning and worldview. Study #2 examined the intersection of science, emotion, and politics in youth writing about climate change, with an analysis of letters written by 350 teenagers across the United States during the lead up to the 2016 Presidential election. Using a mixed-methods approach to analysis, this study identified in these letters three distinct discourses, or ways of discussing climate change: a solution-oriented discourse, a climate politics discourse, and a discourse of doom. This analysis also demonstrates the politicization of climate change for some youth in the US. Study #3 asked about science learning that occurred in a 9th grade classroom in moments when political aspects of climate change emerged through discourse. With sociocultural theory as a conceptual lens, this study used discourse analysis to show evidence for productive disciplinary engagement (PDE) around knowledge of the political dimensions of climate change. It also described moments in which students drew on their own personal political frameworks to navigate issues of science

Keywords: Education.
Advisor: Ardoin Nicole M. (Nicole Michele) 
Brown Bryan Anthony 
Carlson Janet (Associate research professor of education)
Nehruvian Socialism, a Fine Balance: Reconciling Economic Planning and Democracy in Modern India (1947-64)

This work examines the origins of post-colonial India's political economy, and how centralised state planning was reconciled with India's democratic constitution. By analysing the work of Jawaharlal Nehru, India's first Prime Minister, this thesis shows that national unity and poverty were two overarching aims that guided India's political economy in the initial years after independence. After examining the intellectual history of state intervention and economic planning from the 1920s-1940s in the USA, USSR and Europe, the thesis explores how planning was conceived of in India. It also analyses the perspectives of Indian businesses and finally sees how planning was implemented during Nehru's rule from 1947-64 in the form of Five-Year Plans.

Keywords: Vibhav Mariwala
Department of History
Stanford University
Jawaharlal Nehru
Democracy
Socialism
Planning
Keynes
Soviet
Five-Year Plan
The Bombay Plan
Modernity
Constitution
Political Economy
Thesis
Advisor: Hansen Thomas
Crews Robert
Neither blank slate nor set in stone : cultural behaviors of organizational newcomers

This thesis probes the causes and consequences of cultural behavior of new organizational members - newcomers. Chapter 1 models and simulates the effect of inter-organizational mobility on cultural diversity in organizational populations, demonstrating how culture within organizations may be shaped by the behavior of other organizations via culture carriers. Chapter 2 leverages modern tools from computational linguistics to analyze when individuals switch cultural codes following an organizational merger, highlighting the interacting effects of social status and adaptability. Chapter 3 builds on the data and methods developed in Chapter 2 to examine the network conditions that shape emergent cultural change, finding that individuals in brokerage positions are more likely to become sources, or vanguards, of future culture. Collectively, these chapters draw attention to organizational structures and boundaries as key sources of cultural variation and change

Keywords: Business.
Advisor: Carroll Glenn 
Goldberg Amir 
Hannan Michael T.
Srivastava Sameer (Sameer B.)
Nemt altiu maer für niuwe : Wolfram von Eschenbach and the Arabic subtext of Latin Europe from the twelfth century

In my dissertation I analyze Wolframs von Eschenbach's Willehalm and Parzival with regards to the tangible appropriation of elements of Saracen culture. I explore the phenomenon in order to derive through literary analysis a model which which to describe the complex engagement with Arabic Culture in Latin during the twelfth and thirteenth centuries

Keywords: German Studies.
Advisor: Gumbrecht Hans Ulrich
Berman Russell A.
Starkey Kathryn