VictorJuiz/thesis huggingface dataset:
Increasing fuel utilization of breed and burn reactors

Breed and Burn reactors (B&B), also referred to Traveling Wave Reactors, are fast spectrum reactors that can be fed indefinitely with depleted uranium only, once criticality is achieved without the need for fuel reprocessing./nRadiation damage to the fuel cladding limits the fuel utilization of B&B reactors to ~ 18-20% FIMA (Fissions of Initial Metal Atoms) - the minimum burnup required for sustaining the B&B mode of operation. The fuel discharged from this type of cores contain ~ 10% fissile plutonium. Such a high plutonium content poses environmental and proliferation concerns, but makes it possible to utilize the fuel for further energy production./nThe objectives of the research reported in this dissertation are to analyze the fuel cycle of B&B reactors and study new strategies to extend the fuel utilization beyond ~ 18-20% FIMA./nFirst, the B&B reactor physics is examined while recycling the fuel every 20% FIMA via a limited separation processing, using either the melt refining or AIROX dry processes. It was found that the maximum attainable burnup varies from 54% to 58% FIMA - depending on the recycling process and on the fraction of neutrons lost via leakage and reactivity control. In Chapter 3 the discharge fuel characteristics of B&B reactors operating at 20% FIMA and 55% FIMA is analyzed and compared. It is found that the 20% FIMA reactor discharges a fuel with about ~ 80% fissile plutonium over total plutonium content. Subsequently a new strategy of minimal reconditioning, called double cladding is proposed to extend the fuel utilization in specifically designed second-tier reactors. It is found that with this strategy it is possible to increase fuel utilization to 30% in a sodium fast reactor and up to 40% when a subcritical B&B core is driven by an accelerator-driven spallation neutron source. Lastly, a fuel cycle using Pressurized Water Reactors (PWR) to reduce the plutonium content of discharged B&B reactors is analyzed. It was found that it is possible to burn the B&B discharged fuel up to an additional 105.6 GWd/MTIHM and 66 GWd/MTIHM , for melt refining and AIROX, respectively.

Advisor: Greenspan, Ehud
Vujic, Jasmina
Non-Diffusive Heat Conduction in Small Length and Short Time Scale

With the evolution of semiconductor technology toward nanometer size and gigahertz frequency, the traditional diffusive Fourier's law of heat conduction can no longer be applied. To engineer new methods for chip cooling or thermoelectric power generation, understanding the non-diffusive heat transfer in both the length and time domains is important. In this dissertation, the phonon transport at nanometer lengths or gigahertz heating frequencies is investigated using the Boltzmann Transport Equation (BTE)./nRegarding length scale effects, a systematic theory of the phonon thermal conductivity accumulation function was developed to show which phonon mean free paths are important for heat transfer. I show that the nanostructure thermal conductivity can be obtained with only the bulk mean free path spectrum and nanostructure geometry as independent inputs. This theory has been applied to nanowire and in-plane thin film systems. In addition, the length scale effect on the effective conductivity in randomly oriented superlattice polycrystals, which are potential thermoelectric materials, has also been investigated./nRegarding time scale effects, I derived an analytical solution to the BTE under the gray mean free time assumption, and extended the solution to the non-gray regime. With this theory, I can explain the experiments measuring a heating frequency dependent thermal conductivity of semiconductor alloys. I also build up a framework which can be used to extract a phonon accumulation function with respected to mean free time. The similarities and differences of both length and time effects have also been compared and discussed.

Advisor: Dames, Christopher
Gas Storage and Separations in Metal-Organic Frameworks with Open Metal Sites

The work presented in this dissertation describes the synthesis and characterization of metal-organic frameworks for gas storage and separation applications. A specific class of materials investigated is metal-organic frameworks containing coordinatively-unsaturated metal cation sites, as these sites perform the bulk of the work for the separations discussed. A wide variety of techniques and spectroscopic methods are covered, including gas adsorption, structural analysis, infrared and Mössbauer spectroscopies, and breakthrough experiments.

Advisor: Long, Jeffrey R.
"The Sound of Here and Now": Cultural Production, Revivalism, and Amateurism in the Tokyo Garage Rock Scene

This dissertation is an ethnography of the Tokyo garage rock scene, a revival scene in the Tokyo underground comprised of fans and musicians who recycle and recreate Anglo-American rock and roll music from the mid-1960s. Seeped in retro-nostalgic style, garage assumes an orientation to the past premised on a playful, visceral engagement with the cultural objects of yesteryear (the sound recordings, the fashions, the ephemera) that is highly selective and fixated on certain modalities of pastness. In particular, garage rock represents a commitment to the obscure, the local, the noisy, the makeshift, and the trashy./nWith the turn in the humanities and social sciences in recent years towards sound and sensory studies, new avenues have opened to reconsider the intersection of musical style, performance, and the sociocultural--to understand how the experiential domains of affect and performance intersect with wider sociocultural processes. Drawing on fieldwork from the Tokyo underground rock scene, this dissertation explore the aesthetics of excess, trash, and immediacy in the Tokyo garage rock revival. I ask, what tangible effects do these defining features of garage music perform socially? In what ways do they underscore a particular logic of cultural production in underground culture? This dissertation presents a framework to understand style and musicality as more than mere by-products of the social, but as foundational to musical life in all its dimensions./nBy focusing on retro-nostalgic style, this dissertation fills a lacuna in popular music scholarship on the processes of cultural revivalism in contemporary pop culture. To date, the scholarship on music revivalism has been dominated by folk and heritage musics. Unlike heritage culture, which makes virtue of preservation and enshrinement, retro cultures such as garage rock fetishize the playful, sensuous materiality of the recovered objects themselves as the focus of revival rather than a mythologized past or narrativized identity. To this end, I present a unique framework through which to conceptualize music revivalism in pop culture revivals like garage by focusing on the forces of mediation and cultural production in ways that are attuned to the particulars of garage sound and style.

Advisor: Guilbault, Jocelyne
Moving On Up? U.S. Military Service, Education and Labor Market Mobility among Children of Immigrants

This dissertation examines U.S. military service enlistment intentions and post-military education and labor market outcomes among young adult children of immigrants in the United States in the early 21st century. I assert that the military is perceived as an alternative pathway to incorporation among disadvantaged children of immigrants. Rather than relying on ethnic social ties and networks to get ahead as segmented assimilation asserts is necessary for success among disadvantaged children of immigrants, they actively avoid downward mobility by choosing military service as a pathway to mobility. I argue that disadvantaged children of immigrants who aspire to upward mobility are pushed toward military service by structural disadvantages but only those who perceive the military as best option to get ahead make the decision to enlist./nAn empirical investigation of post-military educational and labor market outcomes reveal that military service does not uniformly benefit veteran children of immigrants as they may have hoped. Analyses of nationally representative data, the National Longitudinal Survey of Adolescent Youth (ADD Health) and the Current Population Surveys (CPS) reveal that veteran children of immigrants are less likely to acquire bachelor's degrees and are less likely to be enrolled in post-secondary school than non-veterans by the ages of 24 to 32 but unemployment and earnings are similar between veteran and non-veteran children of immigrants./nHowever, these findings hide the variation underlying these outcomes that are revealed by in-depth interviews with thirty-three veteran children of immigrants. While some individuals seamlessly transition from military service to stable, middle-income occupations in the civilian labor market, others face unemployment, underemployment and obstacles to post-secondary degrees because of non-transferable military job skills and the challenges of transitioning from military to civilian life. Members of a third group were pursuing four-year degrees at the time of their interviews and post-college trajectories have yet to be determined.

Advisor: Bloemraad, Irene
Essays on the Politics of Diversity in Modern America: A Causal Inference Approach

Using methods of causal inference, computational social science and careful qualitative analysis, this thesis examines the roles that race and gender play in three key areas of modern American political life: political polarization, immigration policy and political participation./nIn the first essay entitled "The Big Sort(s): Diversity, White Flight and Polarization in Neighborhoods and Cities,'' I develop the Migration-Flight-Polarization (MFP) hypothesis to explain how changes in diversity brought about by internal migration and immigration hold the key to understanding the connection between residential choice decisions and geographic polarization along partisan and ideological lines. Using an original agent-based modeling simulation and Hurricane Katrina evacuee data collected from schools and neighborhoods in Houston, Texas, I demonstrate that changes in diversity and "white flight'' responses to these changes are responsible for the growing partisan divide in Houston neighborhoods and the City of Houston as a whole./nMy second essay entitled "Not in My Backyard: The Effect of Immigrant Race and Proximity on Immigration Policy Preferences,'' examines the extent to which immigrant race and proximity to a respondent informs immigration policy opinion. Using a survey experiment which employs blurry images of a fictional undocumented Mexican immigrant and respondent Internet Protocol addresses, I randomly manipulate immigrant skin tone and perceived distance between respondents and the immigrant. I find that the effect of race on immigration policy opinion depends upon the perceived distance between the immigrant and respondents. When respondents believe that the immigrant lives nearby, the darker immigrant elicits more anti-immigration responses to immigration policy questions. Conversely, when no immigrant location is provided, the darker immigrant elicits greater pro-immigration responses to the same questions. I also find that attitude polarization on immigration policy increases when respondents believe that the immigrant lives near them. These findings help explain the paradoxical divide between support for pro-immigration policies at the national level and anti-immigration policies at the state level./nMy third essay with Morris Levy entitled "Estimating the Gender Penalty in the House: A Regression Discontinuity Approach,'' brings a novel regression discontinuity design to bear on the question of whether net voter bias against female candidates for office can help explain the limited growth of female election to the House of Representatives. Using house primary vote share as a forcing variable, we estimate the causal effect of a major party nominee's gender on that candidate's general election vote share. Our period of study encompasses all Congressional elections since 1982. Our findings suggest that female Republican candidates that barely win two-person House primaries against males receive a substantial boost in general election vote share. A similar effect among female winners of close Democratic primaries is not found.

Advisor: Gailmard, Sean
The Use of Discretionary Expenditures as an Earnings Management Tool: Evidence from Financial Misstatement Firms

This study examines the use of real earnings management in a setting where earnings manipulation is likely to have occurred. Using firms subject to SEC Accounting and Auditing Enforcement Releases, I find that misstating firms show lower discretionary SG&A but higher discretionary R&D than the control sample in the years in which they overstate earnings. I then investigate whether this result is explained by heightened management incentives to support stock prices. I find evidence consistent with investors overvaluing high discretionary R&D and low discretionary SG&A during misstatement years. Overall, these results suggest that while cutting SG&A is considered a feasible earnings management tool to inflate earnings and stock prices, cutting R&D is not a viable option in a setting where managers desire to signal growth and maintain high stock market valuations.

Advisor: Dechow, Patricia
Regulation of Bacterial Type IIA Topoisomerases

Abstract/nRegulation of Bacterial Type IIA Topoisomerases/nby/nSeychelle Monique Vos/nDoctor of Philosophy in Molecular and Cell Biology/nUniversity of California, Berkeley/nProfessor James M. Berger, Chair/nDNA topoisomerases are ubiquitous and essential enzymes that maintain the supercoiling homeostasis of chromosomes. Decades of research have elucidated how topoisomerases manipulate DNA to introduce or remove supercoils. Recently it has become apparent that these enzymes are highly regulated by cells, often through direct physical interactions with other proteins involved in diverse cellular processes such as replication, chromosome condensation, transcription, and repair. It is largely unknown how these interactions affect enzyme function and localization in cells./nTo gain a better understanding of topoisomerase regulation, I have explored some of the intrinsic and extrinsic mechanisms bacteria use to control their type IIA topoisomerases, topoisomerase (topo) IV and gyrase. This work has revealed intrinsic features that contribute to substrate discrimination by topo IV, determined how a condensin homolog binds and activates topo IV, and uncovered a novel proteinaceous mechanism to inhibit gyrase function. These initial studies provide a framework for understanding how gyrase and topo IV function are integrated into the broader context of the cell through enzyme specific modifications and associations and may provide novel targets for small molecule inhibitors.

Advisor: Berger, James M
A hybrid approach of physical laws and data-driven modeling for estimation: the example of queuing networks

Mathematical models are a mathematical abstraction of the physical reality which is of great importance to understand the behavior of a system, make estimations and predictions and so on. They range from models based on physical laws to models learned empirically, as measurements are collected, and referred to as data-driven models. A model is based on a series of choices which influence its complexity and realism. These choices represent trade-offs between different competing objectives including interpretability, scalability, accuracy, adequation to the available data, robustness or computational complexity. The thesis investigates the advantages and disadvantages of models based on physical laws versus data-driven models through the example of signalized queuing networks such as urban transportation networks./nThe dynamics of conservation flow networks are accurately represented by a first order partial differential equation./nUsing Hamilton-Jacobi theory, the thesis underlines the importance to leverage physical laws to reconstruct missing information (\emph{e.g.} signal or bottleneck characteristics) and estimate the state of the network at any time and location. Noise and uncertainty in the measurements can be integrated in the model. When measurements are sparse, the state of the network cannot be estimated at every time and location on the network. Instead, the thesis shows how to leverage other characteristics, such as periodicity. From deterministic dynamics, the thesis derives the probability distribution functions of physical entities (\emph{e.g.} waiting time, density) by marginalizing the periodic variable. Using a Dynamic Bayesian Network formulation and exploiting the convexity structure of the system, the thesis shows how this modeling leads to realistic estimations and predictions, even when little measurements are available. Finally, the thesis investigates how sparse modeling and dimensionality reduction can provide insights on the large scale behavior of the network. Large scale dynamics and patterns are hard to model accurately based on physical laws. They can be discovered through data mining algorithms and integrated into physical models.

Advisor: Bayen, Alexandre M
It's Personal: The Tangible and In(tangible) and of Aging Out of Foster Care Into Adulthood

Close to 20,000 youth age out of foster care into early adulthood every year, hard pressed to achieve independence at an accelerated pace. Most current state policies require youth to leave foster care between ages 18 to 21, leading to considerably more compressed transition periods than what is typically found among the general population. Though not true of all youth who age out of care, low levels of educational attainment, great economic and housing instability, and generally poor adjustment is well documented among former foster youth in adulthood. In response, legislative efforts have targeted the needs of older youth in foster care for over three decades, primarily focused on teaching youth practical skills for independent living. However, the efficacy of existing independent living skills programs is unclear, resulting in a lack of clarity regarding "what works" in supporting youth during their transition to adulthood. "Soft" resources and skills, such as adult identity and level of personal agency, are also often missing from living skills programs and may be just as important in facilitating stable transitions and nurturing readiness to take on the challenges of adulthood./nThis study investigated transitions to adulthood among youth who aged out of foster care in California. The study sought to move beyond previous research by exploring the utility of a theoretical framework, Côté's identity capital model, for explaining differential pathways to adulthood among youth aging out of care. The first study question examined housing pathways taken by youth after aging out of care, following commonly used models in demographic analyses of pathways in transitions to adulthood. The three remaining research questions focused more specifically on the identity capital model, and explored constructs of adult identity and agency in relation to youth functioning after exiting the foster care system./nSimilar to patterns found among youth in the general population, more than a few youth in the study sample relied on supportive relatives or non-related adults for housing during their transition to adulthood. Many youth in the sample also lived in their own place, and in fact, this was the most common housing status observed among the study sample, by far. Furthermore, very few youth left and returned to a relative home or transitional housing, suggesting youth accessed these housing safety nets on a limited basis. Cronbach's alpha estimates and confirmatory factor analyses (CFA) indicated that previously validated scales used to measure adult identity and agency had low reliability and validity in use with the current study sample. Similarly, CFA goodness-of-fit tests indicated a poor fit of model constructs and indicators to data of the current study sample.

Advisor: Duerr Berrick, Jill
"What's In a Name?" American Parents' Search for the Perfect Baby Name

In the last half-century, the most popular names given to American children have become less common than ever before. Between 1960 and 2010, the percentage of children receiving the top ten most popular names dropped from roughly 22% to 8%. In 2010, almost 10% of American children received names given to fewer than five children born in the country that year. Increasingly, when naming their children, parents from all demographic backgrounds are choosing something "distinctive" or even truly unique. I argue that this shift in practices reflects an increasing cultural emphasis on individuation, as parents struggle to ensure that their children will "stand out" without being branded as strange./nMy dissertation explores the phenomenon of the "widening name pool" using data drawn from a sample of longitudinal birth records and from more than 80 in-depth interviews with contemporary parents and those who named their children in the last few decades. My findings suggest that, rather than a simple side effect of increasing demographic diversity, the shift toward increasing use of distinctive names reflects an active effort on the part of parents to find something "different." Parents explain this choice in terms of a desire to help their child forge a more unique identity, which will also - implicitly - be a stronger one. Contemporary parents feel a sense of pressure to choose a distinctive name, claiming that to do otherwise might lead children to feel somehow less than "special"; however, parents also shy away from selecting a name that could cause children to stand out in the wrong way. My research suggests that, for most parents, the perfectly distinctive name is one with personal meaning for the family, something easily comprehensible by strangers, and in which parents can feel that they've made an "authentic" choice, a concept most often expressed by parents' avoidance of names strongly connected to racial or ethnic groups with whom they have no affiliation./nAlthough contemporary parents choose distinctive names at significantly higher rates than their counterparts from a few decades past, both groups present remarkably similar rationales for their desire for a distinctive name. I thus suggest that the increasing diversity in contemporary names reflects not only the cultural shift toward individuation but also a reaction to the increasing presence of and emphasis on popularity data in the resources available to parents seeking "expert advice" on naming a child. Thus, my conclusion submits that the widening pool of American baby names, motivated by larger cultural forces, is also self-perpetuating as contemporary parents and experts alike become increasingly conscious of the "need" to avoid the most popular names.

Advisor: Swidler, Ann
Vaisey, Stephen