VictorJuiz/thesis huggingface dataset:
Graded index immersion optics with application as solar concentrators [electronic resource]
Keywords: Electrical Engineering.

Axially Graded Index LEns (AGILE), as an effective non-tracking concentrator, was conceptualized, simulated, and fabricated. The results demonstrated how modes/optical power can be confined in a smaller volume in a high refractive index media and paved the way for a passive concentration system coupled to solar absorbers with optical and mechanical bonding, which saves PV (Photo-Voltaic) material cost, and provides space for cooling and circuitry. Most importantly, AGILE prototypes were fabricated in straightforward, inexpensive, and scalable processes. Simple to test and verify, back-to-back AGILEs demonstrated a concentration of up to 10 suns (geometric area ratio) and tracked the theoretical simulations. AGILE is a simple device that rests on fundamental laws and has the potential to greatly improve solar conversion systems by reducing cost, increasing efficiency, and providing a robust modular design with natural anti-reflection and encapsulation. The operational principle of the AGILE is based on the fact that the number of states of an optical aperture is proportional to the square of the Refractive Index (RI), which allows loss-free concentration by a factor of square of RI. Development of AGILE into a practical technology presented substantial challenges in material science and fabrication techniques. After exploring various techniques for making graded index and fabricating optical devices with glass bonding and curing of polymer films, high-quality optics were also fabricated using 3D printing and smoothing technique. A UV gel smoothing technique that can be used with commercial 3D printers (resolution of tens of microns) was conceptualized and developed, and the optical surfaces fabricated gave a rms (root mean square) surface roughness of around 2 nm. Optical components made using 3D printing including mirrors, lenses, and solar concentrator arrays were demonstrated and tested. 3D printing ushers in a new era in optical device fabrication. This 3D printing technique was also used to fabricate and demonstrate high concentration AGILEs of up to 10 suns. Ultimately, AGILE requires transparent, robust, and broadband transparent materials with RI (Refractive Index) gradually ranging from 1 to 3.5 and beyond. Evolution of the AGILE basic structure into a more sophisticated design will involve a robust lens top surface, an optimized side wall profile, and a radial as well as an axial index gradient with nano structuring to couple light from the concentrator to the solar cell. The AGILE fabrication process, once transferred as a commercially technology, has the potential to not only change the way we concentrate light (applications also in illumination, coupling, anti-reflection coatings, and displays), but also the economy and adoption of solar power.
Graphics processing unit accelerated tensor hypercontraction for high performance computing [electronic resource] : a reduction in computational cost of Ab initio methods
Keywords: Chemistry.

Often, the computation of molecular properties requires an accurate description of the electronic wavefunction. Unfortunately, the accuracy and computational demands of a method are typically at odds with each other. In order to reduce the computational demands of ab initio methods, we have developed the tensor hypercontraction approach. In this work, we will show how the tensor hypercontraction approximation improves the efficiency of electronic structure methods while maintaining the accuracy of the underlying ab initio approach. This work focuses on the use of tensor hypercontraction in second-order Møller-Plesset perturbation theory (MP2), second-order approximate coupled cluster singles and doubles (CC2), and the extension of CC2 for excited state computations. Recently, the high performance computing industry has incorporated the use of graphics processing units (GPUs) for general purpose computing. GPUs are massively parallel architectures that are being used to accelerate computationally intensive approaches in a variety of fields, including quantum chemistry. I will show that the tensor hypercontraction methods are highly amenable to parallelization techniques and demonstrate a performance improvement for parallel tensor hypercontraction via parallelization across compute nodes and acceleration with GPUs. I will demonstrate that the use of parallel approaches allows us to extend the applicability of tensor hypercontraction CC2 and excited state computations to chemical system sizes that are challenging for canonical CC2.
The great elector's table [electronic resource] : food and the rise of Brandenburg-Prussia, 1640-1688
Keywords: History.

This dissertation reexamines the rise of Brandenburg-Prussia in the seventeenth century through the lens of food culture. It explores the ways that culture, politics, the natural environment, and science intertwined to define taste at the court of Friedrich Wilhelm (1640-1688). I argue that the decisions about everyday life at court were fundamental to the larger growth of the power of this court on the European political stage and its consolidation of power at a time when most central European states fell into obscurity. This work offers an alternative to the traditional military and bureaucratic narratives of the rise of Prussia. Instead, this dissertation views the military and bureaucratic accomplishments of this dynasty as part of a wider cultural program that shaped the consolidation of the state. In studying the economic, environmental, social, and political dynamics in choices about food at court, this work exposes the micro-decisions that determine the identity of any state.
A ground structure method to optimize topology and sizing of steel frame structures to minimize material, fabrication and erection cost [electronic resource]
Keywords: Civil and Environmental Engineering.

Engineers are often challenged to design steel structures that are safe, economical, constructible. This design process involves specifying each of the following three aspects of the structure: (i) topology, which concerns the number and connectivity of members; (ii) shape, which pertains to the location of structural joints; and (iii) sizing, which involves defining member cross-sections. This thesis presents a method to optimize topology and sizing of steel frame structures to minimize total installed cost while meeting defined safety and constructability requirements. Based on the Ground Structure Method (GSM), the proposed approach begins with an array of nodes that are interconnected with a dense mesh of linear members which have undergone a geometric check to ensure feasibility of fabrication and erection. Each member in the structure is then sized in an iterative process considering the applied forces and discrete set of section types provided. The sizing process ensures that the members are capable of bearing the applied loads and therefore result in a safe structure. Next, each connection in the structure is detailed based on the joint forces and incoming member sizes. The material quantities from the detailed structure are then used to estimate the cost of each member, including connections, based on unit rates that are intended to be provided by the steel fabricator, erector and material supplier. Finally, members in the structure are ranked according to their stress to cost ratio. The topology optimization process functions by systematically removing members in the structure which have a relatively low stress per unit cost until the converged solutions is found. The proposed Cost-Driven Deterministic Ground Structure Method (CDD-GSM) is applied to a typical two-dimensional building braced frame structure in order to demonstrate the method and compare its performance to a typical weight-based GSM approach. While being 18% heavier, CDD-GSM solution is approximately 8% cheaper than the weight-optimal design. These results highlight the limitations of existing weight-based approaches and demonstrates the importance of an accurate cost-based objective function in order to improve the practicality and effectiveness of topology and sizing optimization methods.
Haptic jamming [electronic resource] : controllable mechanical properties in a shape-changing user interface
Keywords: Mechanical Engineering.

Haptic interfaces increase the richness and quality of user interaction with a virtual or remote environment by conveying physical information through the sense of touch. Beyond vibration of a mobile device or force feedback through the end effector of a robot, shape-changing interfaces provide more complete haptic feedback by allowing the user to explore the interface directly with his or her hands. This thesis presents the design, modeling, and control of a novel form of haptic interface inspired by advances in soft robotics and tangible interaction. Haptic Jamming is a technique that combines particle jamming and pneumatic actuation of a surface to achieve simultaneous control of its shape and mechanical properties. A hollow silicone membrane is molded into an array of thin cells, each filled with coffee grounds such that adjusting the vacuum level in any individual cell rapidly switches it between flexible and rigid states. The array clamps over a pressure-regulated air chamber with internal mechanisms designed to pin the nodes between cells at any given height, which provide an extra degree of control over the output shape. Various sequences of cell vacuuming, node pinning, and chamber pressurization allow the surface to balloon into a variety of shapes. Experiments were performed to define the rheological characteristics of jammed systems from a macroscopic perspective that is relevant to force-displacement interactions that would be experienced by human users, expanding upon existing physical models of jamming at the inter-particle level. This provides the framework to tune and control the mechanical properties of a jamming interface. A custom spring-mass deformable body simulation was built combining models of the three actuation inputs of a Haptic Jamming surface: node pinning, chamber pressurization, and cell jamming. The simulation guided the development of an algorithm to generate a sequence of actuation inputs for the surface in order to match desired output shapes ranging from topographical maps to three-dimensional solid object models. The construction of multi-cell arrays integrated with the depth map from an {RGB-D} sensor provides the capability to close the feedback loop on surface shape, resulting in a more compelling display of complex shapes. Ongoing research shows promise to develop Haptic Jamming into a fully three-dimensional device with embedded stretchable sensors, permitting its use as both a computer input and output interface. This technology can enable dynamic tangible environments for applications ranging from medical simulation to product design.
Hardware acceleration of graph analysis applications [electronic resource]
Keywords: Electrical Engineering.

Graphs are powerful data representations favored in many computational domains. Analytics and knowledge extraction on these data structures has become an area of great interest, particularly with the increasing prevalence of large data sets now becoming commonplace in data centers. Due to the scale of these operations, energy efficiency on frequent tasks such as graph analysis will be very important as the domain and the data sizes continue to grow. Dedicated hardware accelerators are one high-performing yet energy-efficient approach to this problem. Unfortunately, they are notoriously labor-intensive to design and verify while meeting stringent time-to-market goals. This thesis presents GraphOps, a modular hardware library for quickly and easily constructing energy-efficient accelerators for graph analytics algorithms. GraphOps provide a hardware designer with a set of composable graph-specific building blocks broad enough to target a wide array of graph analytics algorithms. The system is built upon a streaming execution platform and targets FPGAs, allowing a vendor to use the same hardware to accelerate different types of analytics computation. Stubborn hardware implementation details such as flow control, input buffering, rate throttling, and host/interrupt interaction are automatically handled and built into the design of the GraphOps, greatly reducing design time. As an enabling contribution, this thesis presents a novel locality-optimized graph data structure that improves the efficiency of memory access to the graph.
Harnessing the complexity of complex oxides [electronic resource]
Keywords: Applied Physics.

Human prosperity is driven by technology. And over the past 50 years, much of the tremendous progress in human prosperity has been driven by information technology, especially the semiconductor transistor and Moore's law. However, today Moore's law is ending. Going forward, humanity faces two broad possibilities: either stick with the transistor and settle for a reduced rate of technological progress or, as has been done many times in the past, develop a new computing paradigm with more initial difficulty but higher ultimate potential. One candidate materials platform for a future computing paradigm is complex oxides, whose complexity is both boon and bane. On the one hand, the complexity of complex oxides enables a wide range of tunable properties, such as ferromagnetism, ferroelectricity, and superconductivity. But on the other hand, their complexity makes them difficult to synthesize reliably and difficult to understand. In my PhD, I studied how the behavior of 3d electrons can be tuned in thin films of complex oxide materials. In my first major project, I studied how electrical conductivity could be turned on and off at the interface of LaAlO3/SrTiO3. And in my second major project, I studied how ferromagnetism could be turned on and off in RCo3, where R is a rare earth element. In my LaAlO3/SrTiO3 project, despite the interface's wide variation in reported electrical properties, I highlighted a scaling relationship between sheet carrier concentration and mobility common to nearly all research groups. I also discovered that the electrical transport is robust to the presence of magnetic and spin-orbit scatterers (Tm and Lu) at a 2% concentration in LaAlO3. In cobalt perovskites, I extended the phase diagram of thin film magnetism, exploring the roles of both chemical pressure (through A-site doping) and epitaxial strain. I discovered that although tensile epitaxial strain from SrTiO3 is enough to induce ferromagnetism in LaCoO3 and PrCoO3, it is not enough to induce ferromagnetism in P0.7Y0.3CoO3, which has a smaller and less cubic unit cell. X-ray magnetic circular dichroism revealed that although the Co ions Pr0.7Y0.3CoO3 in were not ferromagnetic, they still possessed magnetic moments, suggesting that the lack of ferromagnetism came from a lack of exchange rather than a lack of magnetic moment. These results highlight the importance of chemical bonding in stabilizing a ferromagnetic ground state and demonstrate new ways to tune magnetic order. Together, these projects provide new insights toward understanding and controlling the behavior of correlated 3d electrons. And they bring us a few steps closer to finally harnessing the complexity of the complex oxides.
Health and Safety Conditions Within the Global Supply Chain of the Electronics Industry: An Investigation of Over 500 Manufacturing Facilities for a Prominent Consumer Electronics Multinational
Keywords:  Department of Biology
Biology
occupational health
Thesis

With the advent of the globalized economy, this has posed a unique threat for the health and safety of workers globally. Now that multinationals can outsource their labor to developing countries for low wages and high scalability of labor forces, there is a growing concern that the working conditions found in these overseas factories—particularly for the electronics manufacturing industry— are dangerous in occupational safety practices, resulting in high rates of injury and documented occupational diseases. Working with a prominent electronics multinational, Firm X, we collected audit data from 538 factories spanning 23 separate countries and 259 cities, the largest of its kind for the multinational. We found that out of the 525 factories that documented accidents or incidents in the past two years, 485 factories (92.38%), reported 0 of either injuries or accidents. A similar trend of little to no reporting was observed for documented abnormal occupational health (OH) exams; out of the 526 factories that documented occupational health exam evaluations, 449 of them (85.36%) reported 0 abnormalities. Overall, 80% of the audited factories reported 0 occupational injuries or abnormal occupational health exams within the past two years, which is vastly below the hypothesized results, insomuch that the credibility of these data was called into question. When compared with national averages and nongovernmental organization (NGO) audits, these data are vastly lower, strongly indicating that underreporting has taken place within Firm X’s supply chain. Thus, we believe that these data do not provide an accurate depiction of injuries rates and occupational-related illnesses for workers within Firm X’s supply chain, calling for improved modes of collecting health and safety reports through the supply chain in order to protect worker health and safety. We believe this finding is not unique to Firm X, and that understanding the working conditions in the electronics manufacturing industry, especially within developing countries, is a continual challenge that must be further investigated.
Heat shock protein 90 and the evolution of antifungal drug resistance
Keywords: Biology
Thesis

Theory holds that the capacity of a population to evolve in response to a selective pressure is due to pre-existing variants. That is, successful alleles are not produced by selection itself but are rather enriched by selection. This line of thinking has recently been challenged by the observation that some types of environmental stress can induce mutations that confer an adaptive advantage in them. Although the generality of such findings is controversial, a number of induced mutagenesis systems have now been characterized at the genetic level in bacteria. Much less is known about whether and how such processes might operate in eukaryotic cells. The highly conserved molecular chaperone Hsp90, which assists in the folding of many proteins that are critical for growth and development, has been proposed to broadly influence the capacity of mutations to produce new phenotypes. Because the activity of Hsp90 is stress-regulated, I investigated whether it might provide a means through which the environment could influence the acquisition of adaptive phenotypes. Using the classic statistical assay known as the fluctuation test, I observed that changes in Hsp90 activity altered the mechanisms by which yeast cells acquire resistance to the commonly prescribed antifungal drug fluconazole. The distribution of resistant variants I obtained suggested that fluconazole exposure itself likely induced the acquisition of resistant phenotypes. In contrast, a distribution of resistant variants consistent with spontaneous appearance was evidence in cells with reduced Hsp90 activity. I observed similar results with the evolutionarily distant human pathogen Candida albicans. These findings establish a means through which environmental stress might influence the fundamental mechanisms of adaptation in eukaryotes and further point to an unappreciated benefit of modulating Hsp90 activity as a strategy to overcome drug resistance in fungi.
Heterogeneity and depletion of the mantle assessed from abyssal peridotite geochemistry [electronic resource]
Keywords: Geological and Environmental Sciences.

Mid-ocean ridges are the surface expressions of plate tectonics and mantle convection, where decompression melting of the upper mantle produces the basaltic crust. Despite the information provided by basalts on mantle composition, they are mixtures of melts sourced from large regions. In contrast, abyssal peridotites are the residues of melting and they can be used to directly study the Earth's mantle in locations where they are emplaced on the seafloor. In this dissertation, I use abyssal peridotites to constrain mantle composition, including evidence for long-term heterogeneity and an exploration of the behavior of the element lead (Pb) -- a key geochemical tracer -- during melting. In Chapter 1, I use peridotites from the ultraslow spreading Gakkel Ridge in the Arctic Ocean to assesses the spatial variation in chemical compositions of peridotite and to explore the long-term effects of ocean ridge melting and refertilization on mantle composition. In chapter 1, the spatial length-scale of compositional variability observed among Gakkel peridotites indicates the existence of a heterogeneous mantle, including refractory mantle produced by ancient melt depletion unrelated to the current ridge setting. Chapters 2 and 3 explore the distribution and partitioning of Pb in the mantle, using peridotites from the Gakkel and Southwest Indian Ridges. Despite the importance of Pb for isotopic models of Earth's geochemical evolution, the mineralogical host of Pb in the mantle is poorly constrained. Sulfide has been suggested to contain the majority of mantle Pb, even though it occurs at modal abundances < 0.1% in peridotite. In Chapter 2, I develop a method for the in situ measurement of Pb and other trace element abundances in sulfides. Sulfides have an average Pb concentration of 2 ppm, which I incorporate into a model of sulfide petrogenesis to suggest that current estimates for source mantle composition contain too little Pb. Finally, Chapter 3 presents a comprehensive mass balance for Pb, by using Pb concentrations in the silicate phases, in addition to the sulfides, to reconstruct whole rock compositions and compare these to the measured whole rock. The results of this calculation show that Pb is hosted in a combination of silicate and sulfide phases, which is key for understanding the transport and long-term storage and abundance of mantle Pb.
High harmonic generation in rare gas solids [electronic resource]
Keywords: Applied Physics.

Strong-field laser excitation in semiconductors and insulators has been shown to produce high harmonic generation (HHG) and other strong field effects familiar in atomic physics. However, in solids, the microscopic processes underlying these effects are not well understood. One way of getting a better understanding is to compare HHG of a single chemical element both in solid and gas phase. In this dissertation I will discuss results of a comparative study of HHG is solid Ar and Kr and their respective gas states. We found that HHG spectra in solid Ar and Kr , which extends to about 40 eV, have secondary plateaus. In addition the cutoff law is well above the one in gas states. Both effects have origin from purely solid state effects. We use a quantum model of laser excitation to interpret our results and make a connection to past results on HHG in solid state, where the apparent differences between interband and intraband currents might just be stemming from vantage view. In addition, there are signs that manybody effects might play an important role in HHG in rare gas solids. Finally, the ellipticity dependence of HHG is as strong as in the case of gases which points to the importance of electron recombination. This means that HHG in solids can be a powerful tool for studying the microscopic and band structure of solids and their excitations.