VictorJuiz/thesis huggingface dataset:
Alternative processing methods and materials for thin film chalcogenide solar cells [electronic resource]
Keywords: Materials Science and Engineering.

CIGS is currently the highest efficiency chalcogenide absorber, with a record cell efficiency of 20.3%. One of the main challenges of CIGS manufacturing is reducing costs and scaling up manufacturing. The use of toxic elements (Se, Te, Cd) and rare earth elements (In, Te) further complicates the materials processing. The development of non-toxic, earth abundant materials to replace these technologies is underway. Furthermore, there is a need to develop scalable and high-throughput manufacturing techniques that could reduce costs and improve manufacturing of chalcogenide solar cells. Solution-based deposition techniques are widely considered to be a route to low-cost, high-throughput photovoltaic device fabrication. Nanoparticle based inks are one means of achieving low-cost and high-throughput solution-processed devices. I study the properties of CuInS2 nanoparticles and their application to solar cell fabrication. I also establish a methodology for a highly scalable deposition process and report the synthesis of an air-stable, vulcanized ink from commercially available precursors. Using this air-stable solution process, solar cells are made with an absorber layer that is flat, contaminant-free, and composed of large-grained CuInS2. I demonstrate an initial power efficiency of 2.15%. To address the challenge of reducing elemental toxicity and the use of rare elements in chalcogenide solar cells, I will discuss some alternative absorbers that don't contain Indium, Cadmium, Tellurium, or Selenium. I demonstrate a 2.2% Cu2SnS3/CdS solar cell using rapid thermal processing and address the challenges facing this material to improve efficiency.
Analyzing staffing and care practices to improve substance use outcomes in VA patients [electronic resource]
Keywords: Management Science and Engineering

Using U.S. Department of Veterans Affairs (VA) records, this dissertation explores the staffing mix in substance use disorder treatment programs (SUDTPs) and the effectiveness of the current clinical practice guideline in reducing suicide risk associated with opioid therapy. The VA treats a large number of Veterans diagnosed with substance use disorders (SUDs) in four types of specialized SUDTPs at an annual cost of more than 50 million. The staffing mixes were not significantly different from 2001 to 2003, the years under review. However, given differences in treatment focus and provided services, the four types of SUDTPs may require different staffing mixes. We demonstrate how cost-effective staffing mixes for each type of VA SUDTP can be defined empirically. We derive prediction functions for benefits and costs based on patients' treatment outcomes at VA SUDTPs nationally from 2001 to 2003, and use them to formulate optimization problems to determine recommended staffing mixes that maximize net benefits per patient for four types of SUDTPs while conforming to limits of current practice. Compared to the actual staffing mixes in 2001-2003, the recommended staffing mixes would lower treatment costs while improving patient outcomes. We also introduce an approach to building a decision support system for staffing each type of SUDTP reflecting the dynamics of effectiveness and costs associated with the staffing changes. Compared to the actual staffing mixes, the staffing mixes suggested by the staffing decision support system are expected to treat significantly more Veteran patients under the existing staffing budget while improving patient outcomes. We also examine associations between adherence to guideline recommendations and the risk of suicide attempt based on Veterans Health Administration (VHA) records. Opioid therapy is often provided to reduce chronic pain in at-risk patients. Unfortunately, available opioid medications have been also used as a means for attempting suicide. In 2010, the VHA and the Department of Defense released a jointly developed clinical practice guideline (CPG) to reduce the risk of adverse events such as suicide attempt in patients prescribed opioids, primarily based on expert consensus. We conduct multivariate mixed-effects logistic regression analyses to define the associations between facility-level CPG adherence rates and risk of suicide attempt while controlling for the associations between individual-level delivery of CPG-based services and the risk of suicide attempt. Major findings include the following: suicide attempts were negatively associated with facility-level adherence rates for both consistent urine drug screenings and follow-up appointments, and were positively associated with facility-level risky sedative co-prescription rates.
Anti-CD47 antibody-mediated phagocytosis of cancer by macrophages primes an effective anti-tumor T cell response [electronic resource]
Keywords: Cancer Biology.

Mobilization of the T cell response against cancer has the potential to achieve long-lasting cures. However, it is not known how to optimally harness antigen presenting cells to achieve an effective anti-tumor T cell response. In this study, we show that anti-CD47 antibody-mediated phagocytosis of cancer by macrophages can initiate an anti-tumor T cell immune response. Using the ovalbumin model antigen system, anti-CD47 antibody-mediated phagocytosis of cancer cells by macrophages resulted in increased priming of OT-I T cells (CD8+), but did not prime OT-II T cells (CD4+). The CD4+ T cell response was characterized by a reduction in Foxp3+ regulatory T cells. Macrophages following anti-CD47-mediated phagocytosis primed CD8+ T cells to exhibit cytotoxic effector function in vivo, protecting animals from tumor challenge. We conclude that anti-CD47 antibody treatment not only enables macrophage phagocytosis of cancer, but can also initiate an anti-tumor cytotoxic T cell immune response. Anti-CD47-mediated phagocytosis of cancer cells by macrophages leads to priming of a predominant CD8+ T cell response without priming of CD4+ T cells, demonstrating differential priming of T cell responses by macrophages. Priming of effector CD8+ T cells is difficult to achieve with existing vaccines for cancer and infectious diseases. Anti-CD47-based vaccination strategies serve as a promising new strategy for overcoming this challenge for treating or preventing human disease.
Antimonide-based III-V CMOS technology [electronic resource]
Keywords: Electrical Engineering.

As scaling of silicon CMOS becomes increasingly difficult, use of alternate materials with high carrier mobilities is being explored extensively. Despite burgeoning interests in III-Vs for realizing high performance transistors at low power, III-V MOSFETs have been plagued by (a) Poor PMOS performance, which makes realizing CMOS in a single material system difficult; (b) Low density of states (DOS) for electrons; (c) Poor surface passivation resulting in high interface trap density; (d) Poor dopant activation in the source-drain (S/D); (e) High contact resistance; (f) Hetero-integration of III-V materials on silicon substrates. This work will present novel solutions to overcome these problems. The design is based on the 0.61-0.62nm lattice constant system with InGaSb as the channel material because of its advantages in terms of band engineering and high mobility/offsets for both electrons and holes. The goal is to achieve high electron/hole mobility in the same channel material for N- and P-channel MOS devices through the optimization of surface passivation, stoichiometry, heterostructure design and novel contact/interface engineering. Hetero-integration on a silicon substrate is another key challenge in enabling III-V CMOS. The hetero-integration scheme for III-V CMOS transistors on silicon using the rapid-melt-growth (RMG) technique is demonstrated.
Anxiety and test performance [electronic resource] : an emotion regulation perspective
Keywords: Psychology.

It is widely recognized that anxiety can influence performance in test-taking situations. However, surprisingly little is known about the mechanisms that underlie these effects. In this dissertation, I first review the literatures on test anxiety, stereotype threat, and choking under pressure in order to clarify the mechanisms that underlie the association between test anxiety and test performance. In my review of the literature, I describe how test anxiety is triggered, how it unfolds over the learning-testing cycle, and how it may influence test performance. I then consider how test anxiety may be (and often is) regulated, and consider the direct and indirect effects emotion regulation might have on performance in test-taking situations. Next, I present data from a series of studies in which I examined the effects of cognitive reappraisal and expressive suppression on test anxiety and test performance. Specifically, in Studies 1-2, I investigated expressive suppression as a source of interference during diagnostic test-taking, finding that those high in trait test anxiety use more expressive suppression, and expressive suppression is associated with poorer performance and measures of cognitive interference. In Studies 3-4, I investigated cognitive reappraisal as a test anxiety intervention, finding that cognitive reappraisal of the test situation improves outcomes for the highly test anxious, but that cognitive reappraisal of arousal can lead to paradoxical performance decrements consistent with test anxiety. Finally, in Study 5, I compared and contrasted expressive suppression and cognitive reappraisal in a test-taking paradigm, finding no significant effects of these manipulations on outcome measures. However, within the control group, I found that the association between test anxiety and cognitive interference is mediated by the use of expressive suppression. Taken together, the findings from these 5 studies suggest that test anxiety often triggers an increased usage of the strategy of expressive suppression, which can lead to worse performance, and that test anxiety performance decrements can be alleviated by cognitive reappraisal of the test situation.
The appeal of the (high) road less travelled [electronic resource] : why moral actions become more appealing when no one else does them
Keywords: Business.

Previous research has documented the power of descriptive norms to increase prosocial behavior, but has largely neglected the possibility of uniqueness as a motivator of prosocial behavior. Although theories of normative influence predict that social information indicating that a behavior is rare will dissuade others from taking action, I predict that low rates of prosocial behavior can be particularly motivating, prompting prosocial action on par with descriptively normative behavior. Study 1 explores the real experiences of unique behavior among entrepreneurial chefs through a series of qualitative interviews. Results from Studies 2 and 3 suggest that counter-normative social information increases individuals' willingness to engage in prosocial behavior relative to a baseline condition. Further, Studies 4 and 5 explored divergent psychological mechanisms responsible for descriptively normative and counter-normative social influence. Results from Study 4 suggest that while individuals spurred to behave prosocially when it is normative to do so experience no positive benefit to their self-worth because that behavior is common, individuals who engage in counter-normative prosocial behavior show increases in the perceived identity centrality of those behaviors because that behavior is distinctive. Consistent with this psychology, results from Study 5 reveal that individuals who have engaged in counter-normative prosocial behavior do so as an identity opportunity rather than from feelings of obligation, and these individuals express more pride than those whose prosocial behavior is more common. Thus, individuals who are motivated to take rare prosocial action, but not those motivated to take common prosocial action, may do so because they foresee the opportunity of a prospective enhancement to their self-worth.
Application optimized computing [electronic resource]
Keywords: Electrical Engineering.

All computing systems are power limited, whether it is the 1W limit of a cell phone, or the 100W limit of a server. Triggered by the end of voltage scaling, the restricted power budgets are the result of energy per transistor switch scaling slower than the number of transistors on the chip. Since technology scaling no longer provides the energy savings it once did, to scale performance (operations/sec), we must improve the energy per operation by reducing the number of transistors involved in each operation. This fundamental change is forcing the design community to find new approaches to energy efficient computing. Most designs use pre-designed processor based solutions because of their flexibility and availability. However, they are usually not the most energy efficient solutions. To better understand the potential of producing general-purpose chips with better efficiency, this thesis tries to analyze in detail the types of inefficiencies that exist in general-purpose systems - designs that can be outclassed by up to 3 orders of magnitude in both performance and energy-efficiency by ASIC designs. To collect this data, we classify applications using the dominant sources of energy: compute, control and memory. For compute and control bound applications we gather this data by first identifying the types and magnitudes of energy overheads that exist in a general-purpose Tensilica based extensible RISC chip multiprocessor (CMP) system and then by exploring the architectural support and customizations needed to transform a general-purpose system to have the same energy efficiency as an ASIC. Because the fundamental operations in compute bound applications are generally very low-power, amortization of overheads introduced by programmability requires execution of hundreds of these operations in one cycle. Interestingly, a high percentage of compute bound applications share common data-flow characteristics, which we exploit to create a flexible yet efficient domain specific processor, called the Convolution Engine. Although, control bound applications also operate on low-power control flow operations, sequential dependencies restrict the number of control flow operations fuseable into one instruction to between ten and fifteen. This restriction also defines the extent of achievable efficiency for control bound applications. Unlike the low-power operations abundant in compute and control bound applications, the fundamental cost of a memory fetch is considerable. Improving the system efficiency of memory bound applications not only requires improving the efficiency of the processing elements, but also requires substantially increasing reuse in data fetches.
Approaches for local false discovery rates [electronic resource]
Keywords: Statistics.

Modern hypothesis testing problems involve a large collection of hypotheses H_1, ..., H_N. The Bayesian local false discovery rate is the posterior probability that a hypothesis is null. The local false discovery rate paradigm is therefore an intuitive and attractive approach for deciding which hypotheses to declare as non-null. Accurate local false discovery rate estimation relies on positing an appropriate null distribution, which should be empirically estimated. It is often reasonable to estimate the null distribution from data that is truncated over a region which can safely deemed to be null. This truncation approach is appealing since it enriches the class of models that can be used as candidate null distributions. We propose the use of a log-concave null distribution as a non-parametric extension of earlier local false discovery rate work. Moreover, the truncation approach has a missing data interpretation. For exponential families, a general but simple EM algorithm can be constructed to obtain the maximum likelihood estimates without having to solve the corresponding score equations, which may be awkward in the case of truncation. We verify the correctness of the algorithm by applying Louis' formula (1982).
The archaeology of reform at a German prisoner of war camp in a Canadian national park during the Second World War (1943-1945) [electronic resource]
Keywords: Anthropology.

During the height of the Second World War pressure from Great Britain resulted in the transfer of thousands of German prisoners of war (PoWs) from British to Canadian control. To house them, Canada built a system of PoW camps, including Riding Mountain Camp in southwestern Manitoba. The PoWs sent there soon realized their good fortune: they lived in warm barracks, ate abundant food, and were able to purchase goods from a mail order catalog. But while the PoWs were well treated, they were at the same time subjected to a concerted reeducation campaign organized by the Allies. This reveals that these Canadian camps were not merely warehouses for the PoWs, but in fact, classic reforming institutions. Initially subjected to ideological training under Nazism, the PoWs were next subjected to another kind of education under the Canadians. Evidence collected from oral history interviewing, archival research, and three seasons of field archaeology combine to reveal that material culture was a key nexus in this competition for the minds of the PoWs. In addition to providing books and teaching courses on history and political science, the Canadians introduced the PoWs to a democratic, capitalistic way of life by familiarizing them with North American consumer goods and by allowing them to fraternize with Canadian civilians. The Nazi bureaucracy, in turn, used material things to try to keep the PoWs from turning to the other side. For example, by sending them crisp new Wehrmacht uniforms from Germany, heartening Christmas cards, and packages filled with German goods adorned with Nazi symbolism.
Asymptotically valid and exact permutation tests [electronic resource]
Keywords: Economics.

Given independent samples from P and Q, two-sample permutation tests allow one to construct exact level tests when the null hypothesis is P = Q. On the other hand, when comparing or testing particular parameters [theta] of P and Q, such as their means or quantiles, the classical permutation tests need not be level [alpha], or even approximately level [alpha] in large samples. Under very weak assumptions, this dissertation provides general test procedures whereby the asymptotic validity of the permutation test holds even when the assumption of identical distribution is unknown, while retaining the exact rejection probability [alpha] in finite samples when the underlying distributions are identical. A quite general theory is possible based on a coupling construction, as well as a key contiguity argument for the multinomial and multivariate hypergeometric distributions. The mathematical and statistical foundations for understanding permutation tests are laid out. Based on these technical arguments, the ideas are broadly applicable and generalizations have been made to the k-sample problem of comparing general parameters, the two-sample U-statistics, and d-dimensional multivariate cases and multiple testing. In the U-statistics case, we consider the Wilcoxon statistic or some rank statistics where the parameter of interest is a function of the joint distribution [theta](P, Q) and not just a simple difference [theta](P) - [theta](Q). In multivariate case, we apply the modified Hotelling's T^2-statistic as well as tests based on the maximum of studentized absolute differences. In the latter case, we must employ a bootstrap prepivoting operation, which leads to a bootstrapping after permuting algorithm. Then, we apply these tests as a basis for testing multiple hypotheses simultaneously by invoking the closure method to control the Familywise Error Rate. Monte Carlo simulation studies illustrate how the classical permutation tests and the proposed new permutation tests perform under various scenarios of underlying distributions with small, moderate, and large samples. Lastly, we also present some economic empirical applications where the permutation tests are utilized for testing some parameters of the underlying distributions.
At the center of the periphery [electronic resource] : oil, land, and power in Baku, 1905-1917
Keywords: History.

At the turn of the twentieth century, the output of the Baku oilfields accounted for half of the world's crude oil. This was not accomplished by government fiat or the workings of a monopoly, but by a large and variegated group of workers and entrepreneurs within well-defined market structures, a development all the more remarkable for its rarity in Russian history. However, the oil industry was already threatened by the seeds of its own success. As oil made the transition from a source of illumination to a source of energy, it became the subject not only of increased demand but of intense political contestation as well. The fate of the oil industry became entangled with the outcome of broader debates within Russian society about the proper role of the government in protecting the public interest and the legitimacy of private property. This dissertation recounts how these struggles played out and demonstrates their impact at the local and translocal levels: productive plots found no lessees, workers went on strike, restive villagers dug their own wells, and increasingly antagonized ethnic groups killed each other in growing numbers. All the while, the oil industry in Baku continued to decline, the first oil industry to do so under the weight of political pressure.
Attentional bias in social phobia [electronic resource]
Keywords: Psychology.

Social phobia (SP) affects more than 10% of American adults in their lifetime. A negative attentional bias is one of the best studied factors that contributes to the maintenance of SP; many studies have demonstrated that individuals with SP show biases to attend preferentially to social threat. Recently, researchers have begun to demonstrate that manipulating attentional biases can induce anxiety in non-anxious individuals or alleviate anxiety in anxious individuals. Therefore, it is important for both researchers and clinicians to gain a better understanding of the attentional biases that characterize SP. In the current research, participants with SP and healthy control participants with no history of mental illness completed three tasks: a behavioral attentional cueing task that yields separate measures of engagement with and disengagement from social threat; a free-viewing eye-tracking task in which positive, negative, and neutral emotional faces were presented for the participants to view over a 15-second period; and an antisaccade task that tests participants' ability to control the shifting of attention to positive and negative emotional stimuli. The results demonstrate a deficit in attentional control in individuals with SP on exposure to social threat stimuli, followed by avoidance of these stimuli. At long exposure times, attentional deployment seems to be influenced more by elaborative processes than it is by SP.