VictorJuiz/thesis huggingface dataset:
Photon management in solar cells [electronic resource]
Keywords: Applied Physics.

2015 is the International Year of Light. While we celebrate past and present triumphs of light sciences, our society is undergoing an inevitable and far-reaching transition from indirect, inefficient, and non-renewable to direct, efficient, and renewable methods to utilize the energy from sunlight. Fossil fuels allow us to use solar energy captured by ancient biological materials, which did not necessarily evolve to maximize the energy harvesting efficiency. As we continue to deprive the natural resources, they will be increasingly too costly to recover and too valuable to burn, not to mention present and future environmental externalities. The optimal method to harvest the abundant solar energy consists of using solar cells, which absorb sunlight in semiconductors and convert the photon energy to more easily usable forms. With an array of maturing technologies such as concentration, storage, and smart grid, the solar industry is expected to grow substantially at least in the long run. An optoelectronic device, the solar cell requires photon management for efficiency enhancement and cost reduction, both of which are critical for any commercial success. With these objectives in mind, this dissertation concerns the optimal use of photonic methods for the improvement of optical and electronic performances of solar cells.
Photovoltaic restoration of sight in animals blinded by retinal degeneration [electronic resource]
Keywords: Electrical Engineering.

Retinal degenerative diseases, such as age-related macular degeneration and retinitis pigmentosa, are the leading untreatable cause of blindness in the world. In these diseases, the progressive demise of the image-capturing photoreceptors renders the eye unable to translate visual information into neural signals. However, to a large extent, the image-processing inner retinal neurons survive the degeneration process. Building up on the success of cochlear prostheses, retinal prostheses aim at partial restoration of sight by electrical stimulation of these surviving neurons. While several types of retinal implants demonstrated their ability to elicit percepts of light in blind patients, they suffer from a number of shortcomings. Power cables and bulky intraocular electronics make the implantation procedure very difficult, prone to complications, and the devices often fail over time. Visual percepts are frequently distorted, spatial resolution is low, and patients report only a very limited number of levels of gray. This work presents the design and characterization of a fully wireless subretinal visual prosthesis, in which photovoltaic pixels are activated by pulsed near infrared light (880-915 nm). Pixels that are 140 µm and 70 µm-wide safely elicit retinal and cortical responses both in-vitro and in-vivo in animal models of retinal degeneration. Network-mediated retinal stimulation is highly localized, restoring up to half the normal spatial resolution in blind rats, and geometrically translating to the spatial resolution expected from a person with 20/250 visual acuity. Furthermore, it preserves many features of natural vision, including flicker fusion, adaptation to static images and transient responses to changes in luminance. We conclude by describing the contrast sensitivity of prosthetic vision, and show how image processing prior to projection onto the implant can enhance system performance.
Phrasing the Enemy: The Evolution of Counterterrorism Language and Policy Across the Transatlantic Alliance After 9/11
Keywords: terrorism
rhetoric
transatlantic
alliance
Europe
Bush
counterterrorism
CISAC
Center for International Security and Cooperation
Thesis

In the aftermath of the September 11, 2001 terrorist attacks, George W. Bush launched both a metaphorical and real war on terror. As Bush’s war had global implications, one key objective in his rhetoric throughout his presidency was to convince the international community — and, specific to this thesis, his European allies— to join his cause. Success in this regard would mean that his allies join his efforts in the Middle East and also create counterterrorism policies at home that align with Bush’s conception of the war on terror. As reflected in Bush’s language, Bush’s policy decisions are guided by a key unifying theme: that the fight against terrorism is a higher calling, an effort sanctioned by God, goodness, and abstract values of liberty and freedom. To Bush, this fight against terrorism answers to a higher order and thus transcends the traditional rules and relationships that govern domestic and international society. These rules are simply roadblocks to his pursuit of a higher form of justice.
Europe does not understand terrorism this way, and Bush ultimately fails to convince them. European conceptions of terrorism are firmly rooted in a respect for traditional rules and norms of international society, and Bush’s stylistic attempts at multilateralism cannot alter this foundation. However, a profound tension emerges within the European policies implemented after 9/11, as European policies converge around that intensive American spirit, taking on the more unbounded, self-justifying character of American counterterrorism while still being formally restricted within the auspices of established legal frameworks.
Plasma production and radiation from meteoroid impacts on spacecraft [electronic resource]
Keywords: Aeronautics and Astronautics.

Spacecraft are routinely bombarded with both human-made and naturally occurring dust particles, which we will collectively refer to as hypervelocity particles. Hypervelocity particles possess enough energy to ionize and vaporize themselves as well as a significant portion of the spacecraft material upon impact, forming a plasma that rapidly expands into the surrounding vacuum. The associated electrical effects and potential for damage to satellite electronics through these processes remains largely unknown, but it has been proposed that under certain conditions this plasma can produce an electromagnetic pulse (EMP) which can threaten spacecraft electronics. This area of spacecraft engineering requires a deeper understanding of the underlying physics of the impact-generated plasma plume. This dissertation describes multi-physics simulations of hypervelocity impact plasmas. The simulations utilize a combination of smoothed particle hydrodynamics (SPH) and discontinuous Galerkin (DG) particle-in-cell (PIC) techniques running on graphical processing units (GPU). The results show a minimum velocity threshold of approximately 18 km/s for fully ionized plasma production, which matches the velocity threshold for EMP measurements from impact experiments. The fully ionized plasma produces electrostatic oscillations that can couple to an electromagnetic wave that propagates away from the plasma. Near the impact site, this wave has a field strength that far exceeds the specification to which spacecraft are currently designed. Understanding key parameters of impact plasmas, as well as any EMP mechanisms, will aid in designing more robust and reliable spacecraft that are well protected in the space environment.
Plasmonic nanoparticles in the quantum size regime [electronic resource]
Keywords: Materials Science and Engineering.

Nanotechnology development has been majorly driven by the dramatic alteration and emergence of new material properties as dimensions are decreased. In recent years, noble metal nanoparticles have attracted substantial interest owing to their ability to manipulate light on the nanoscale through localized surface plasmon resonances (LSPRs). These collective oscillations of conduction band electrons result in strong optical absorption and scattering in subwavelength structures and enable applications including molecular detection, cancer treatment, and tunable nanoantennas. While the plasmonic properties of individual particles with diameters > 10 nm and multiparticle systems with gap sizes > 1 nm have been experimentally characterized and well-described with classical electrodynamic theory, LSPRs in smaller nanostructures have historically been poorly understood. Experimental observations below these dimensional thresholds have been limited by optical detection and fabrication techniques, precluding analysis of a size regime with the potential for ultrasensitive monitoring and catalysis. This dissertation describes newly-developed approaches to probe plasmonic nanoparticle systems as their dimensions enter the quantum size regime. Our approach relies on scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS), which allow high-resolution correlation of plasmonic nanoparticle structure with spectra. First, we explore individual metallic nanoparticles with diameters ranging from 20 nm down to 2 nm. As the particles transition from a classical to a quantum-influenced regime, they reveal substantial resonance shifts that deviate from classical electrodynamic predictions. An analytical quantum mechanical model is developed to explain this divergence as function of altered particle permittivity, accounting for the discretization of energy states as particle diameter decreases. Next, resonantly-coupled multiparticle systems including dimers and trimers are discussed. Using a novel electron beam manipulation technique, the separation distance between adjacent particles can be reduced to Angstrom scales. Experimental EELS analysis of dimers reveals non-classical spectral trends and that closely correlate with state-of-the-art quantum models incorporating electron tunneling. Trimers are additionally found to support a greater variety of resonant modes through selective electron beam excitation, and demonstrate both classical and non-classical spectral evolution at sub-nanometer gaps. The study of these quantum-influenced single and multiparticle systems will inform the design of future ultrafine plasmonic sensors, as well as support new interdisciplinary exploration bridging molecular electronics, nonlinear optics, and plasmonics.
"Plugging In" [electronic resource] : disability and the body electric in contemporary American literature
Keywords: English.

This study shows how contemporary American authors provide a new understanding of disability that also challenges long-held assumptions about postwar information culture. My readings analyze portrayals of disability in contemporary literature that figure the disabled body as a communication system that can be electronically manipulated or "plugged in." This mode of literary characterization, I argue, stems from early information theory and communication engineering. The idiom of "plugging in"—what I define as a literary representation and a cybernetic action of embodiment—that circulates in American fiction and in public discourse further reveals how disability and material technologies interrelate. Charting the disabled body's transformation into a "body electric" from the early Cold War era to the present, this dissertation offers a cultural and literary framework for understanding human-machine interaction. By most critical accounts, the discipline of cybernetics decoupled information and human bodies. My readings reorient this narrative, demonstrating that the theory of information was rooted in the disabled body all along. I show how, for example, mathematician Norbert Wiener's little known prototype for a prosthesis transformed amputee stumps into myoelectric "sockets" that relayed neural information. When we attend to these material configurations, we see how cybernetics preserved a specific kind of "dysfunctional" body distinguished by neurological disorders and missing limbs in the design of its information machines. I contend that contemporary authors such as Bernard Wolfe, Thomas Pynchon, William Burroughs, Ken Kesey, Alice B. Sheldon, William Gibson, and John Scalzi sustain this legacy by adopting disability as a heuristic tool for understanding new modes of electronic communication. Their stories frame a historical arc that identifies four interlocking technoscientific movements from the late 1940s to the present: the rise of cybernetics in the early Cold War Era (1940s-60s); the emergence of the cyborg—or what literary theorist N. Katherine Hayles calls "the body of information"—during the Space Race and countercultural era; nascent computing and Internet culture in the 1980s; and global information culture and the turn toward brain-computer interfaces (BCIs) in the twenty-first century. The texts I read in the first three chapters, from Bernard Wolfe's Limbo (1952) to Thomas Pynchon's The Crying of Lot 49 (1966), offer a corrective to histories of science and technology in which the disabled body is largely absent. The final chapter concludes with a study of speculative fiction in the new millennium that turns to disability as a collective site to imagine more inclusive technological futures. This project ultimately argues that contemporary literature provides an antidote to prevailing cultural accounts that that myopically frame disability as a historically inert subject position, revealing that disabled bodies actively shape the way we use and understand technology today.
Policing and the creation of an early modern city [electronic resource] : Moscow under Catherine the Great, 1762-1796
Keywords: History.

Eighteenth-century rulers strove to remake Russia according to their ideas of enlightenment and modernity. Moscow, the country's largest city and traditional capital, served as a particular focus of reform. According to contemporary elites, Moscow's haphazard planning, superstitious populace, and decentralized administration represented the antithesis of the well-ordered capital befitting Russia as a European power. Efforts to remedy these shortcomings culminated in Catherine the Great, who introduced a series of reforms to "Europeanize" the city. This dissertation challenges assumptions that Catherinian policies brought much-needed changes to a city mired in dysfunction and fundamentally backward in comparison to the West. It does so by focusing on the Moscow Police, the institution championed by authorities as the practical means to root out behaviors and practices deemed contrary to enlightened good order. Policing in practice worked to supplant functioning administrative structures and social relationships in favor of imposing alternatives that would be much more transparent and responsive to central authorities. The language of disorder and "Europeanization" thus belies how Russian rulers wielded reforms to achieve goals in Moscow shared by their early modern European counterparts, namely to concentrate authority in central institutions and authorities and to exercise an unprecedented measure of control over the lives of their subjects.
Politics at the intersections [electronic resource] : race, ethnicity, and gender in political identity and behavior
Keywords: Political Science.

How do multiple identities jointly shape political attitudes and behavior? In this dissertation project, I investigate three separate questions about the simultaneous effects of race/ethnicity and gender on American political behavior. Together, these three papers demonstrate the contingent effects of multiple identities. Treating identities as singular and independent obscures the way that multiple identity categories affect political experiences. In Chapter 2, I use two novel survey experiments to test how negative stereotypes about race and gender subgroups can transform into positive perceptions of candidate competence under racialized conditions. In the first experiment, I test the theory of stereotype transformation by priming White respondents with information about rising local crime rates prior to offering a choice between two candidates in an intra-party mayoral race. Consistent with theoretical expectations, highly qualified Black male challengers are advantaged relative to other candidates when respondents are informed that crime is on the rise. The second survey experiment supports the theoretical basis for this counterintuitive result: associations of African-American men with violence lead to stereotypic assumptions that Black male candidates are best equipped to handle crime policy. The findings suggest an exciting new understanding of the relationship between group stereotypes and political behavior. In Chapter 3, I leverage random assignment in a national survey of Latino Americans to test the effects of race/ethnicity, out-group ties, and racial threat on the boundaries of Black-Latino electoral cooperation. I develop and test a theory that the threat of anti-Latino discrimination broadens Latinos' conception of the in-group beyond ethnicity to include other racial minorities. In turn, this increases Latino support for Black candidates who challenge White incumbents. I find that this effect is contingent on Black candidates signaling their ties to Latino interest groups, and that racial resentment and panethnicity moderate treatment effects. In Chapter 4, I use observational mass attitude data and novel survey experimentation to investigate the gender gap in African-Americans' racial linked fate. I argue that gender discrimination limits African-American women's belief that their own fate is tied to the fate of their racial group. Using both the oversample data from the 2012 ANES and new experimental evidence from a national survey of African-Americans, I find that perceptions of gender marginalization reduce racial linked fate among African-American women. However, when racial and gender disadvantage are primed simultaneously, linked fate among African-American women does not diminish. The findings indicate the need to analyze diversity within the Black population, and suggest a need to reexamine the theoretical foundations of linked fate theory.
Politics of Cultural Representation Afro-Ecuadorian Narratives in a Plurinational Framework
Keywords:  Department of Anthropology
Ecuador - Social life and customs
race
performance
Esmeraldeñan culture
cultural representation
ethnicity
marimba
Afro-Ecuadorian identity
Stanford University Department of Anthropology
Thesis

The thesis presents a historical as well as theoretical analysis of what Afro-Ecuadorian identity is—that is not a set of innate characteristics but rather actively constructed representations, in this case created by artists and musicians in relationship to their personal lives as well as the active discourse of their positions and shared experiences in relationship to broader Ecuadorian society. Furthermore, I suggest that Afro-Esmeraldeñan artists, particularly musicians and dancers, are an important part of the creation of cultural representations that travel and are shared with people across different spaces. As one artist elaborates, they are the ‘material authors’ of their identity and without their work, their expressions and the knowledge communicated through them would not exist—whether that be an explicit politics of resistance or a choreography that has been danced a million times that tells an ‘ancestral story’ (Interview, July 18, 2014). Marimba as a form of musical expression and dance to the rhythm of marimba cannot be dismissed as merely superficial understandings of ‘a people’ or merely a stereotype, but as a space in which a broad range of people interact, interpret and create meaning about their own identities and what it means for them in relationship to ‘Afro-Ecuadorian’ identity.
The politics of military operations [electronic resource]
Keywords: Political Science.

Do domestic political institutions affect the way that states fight wars, and if so, why? I argue that military operations on the battlefield are systematically influenced by civilian politicians to favor lower-risk strategies in the months preceding a domestic election. Because domestic constituencies are casualty-sensitive, democratically elected civilians face strong incentives to temporarily trade long-term strategic success for a short-term decrease in casualties, resulting in the direct and indirect politicization of military operations. Direct politicization occurs when civilians intervene in operations through direct requests, increasing monitoring, or changing tactical guidelines, while operations are indirectly politicized when the military polices its own behavior in response to organizational, bureaucratic, or personal incentives. This culminates in a preference for defensive operations in the months leading up to a domestic election, while high-risk offensive strategies are delayed until after electoral pressures have been resolved. The first empirical chapter uses the insights developed in my theory to systematically test the effect of electoral cycles on troop movement and violence levels during the wars in Iraq and Afghanistan. I then use both most different and most similar case designs to qualitatively evaluate the timing of military operations during the wars in Vietnam and Iraq. The third and fourth empirical chapters evaluate systematic deviations and patterns in bombing operations over North and South Vietnam using a recently released dataset that enables analysis of bombing runs from 1965 to 1975. Finally, I conclude with a comparative case study of the strategic bombing campaigns as executed by the United States and United Kingdom during World War II. In each case, I show that domestic politics profoundly influence civilian decision-making during conflict, and that this influence is most pronounced in the months immediately preceding an election. These findings challenge our current understanding of battlefield effectiveness, normal civil-military relations, and how democracies fight wars more generally.
The politics of Native American theatrical adaptations [electronic resource]
Keywords: Theater and Performance Studies.

Educated at top colleges and universities, Native American theater artists now hold mastery and authority over classic western theater texts. These individuals do not necessarily embrace western theater practice as the gold standard but, instead, combine remnants of their indigenous cultures with their sophisticated learned knowledge of European performance traditions. For generations, American Indians were targeted for genocide and cultural eradication, isolated by geographical and ideological boundaries specifically constructed to make European colonists feel comfortable with, distinct from, and superior to "The New World's" indigenous peoples. This dissertation is not intended to re-litigate the traumatic histories of Native America nor is it to chronicle the rise of the numerous stereotypical depictions that now dominate our current pop-culture imaginings. This project considers these to be self-evident phenomena. Instead, this dissertation offers a close investigation of the virtuosic mastery many American Indian theater artists hold over Euro-America theater making: an expertise that gives them the ability to transform narrow yet rigid ideas of Native American existence. Theatrical adaptations by New York City's Spiderwoman Theater, Los Angeles' James Lujan, and Honolulu's Taurie Kinoshita do not align with predictable non-Native cultural imaginings of American Indian existence. In fact, each of these artists has adapted a classic western theater work not as a simple homage and recapitulation of the famous source material but as a new theater work suited to a unique worldview and set of artistic inquiries. These new theater works challenge many long held beliefs of American Indian culture, experience, and identity.