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Optimization-based network modeling of the chemical and refining industry
Full text linkThe U.S. energy landscape has changed drastically in the past years, not only solidifying the country as a key player in the global energy markets, but also having profound effects on the chemical and refining industries, by providing an abundance of Natural Gas Liquids (NGLs) that serve as versatile feedstocks. The evolving role of these industries and their complex interdependence necessitate advanced tools for modeling and optimization. The first part of this dissertation develops a comprehensive superstructure network model of the entire U.S. chemical and refining industry. This model aims to predict potential future trajectories of these industries under various scenarios related to the availability and utilization of fossil fuels. The model could serve as a crucial tool for forecasting shifts in chemical manufacturing considering specific constraints or technological innovations that capitalize on NGLs or alternative fuels. The second part focuses on regional, spatially-resolved network models to evaluate new chemical production technologies. Focusing on the Marcellus Shale region, the model identifies the optimal locations and maximum adoption costs for new technologies, with a case study on chemical plants that produce gasoline from ethylene. Time resolution is added to this model to provide a dynamic perspective, addressing questions around the potential for new chemical processing technologies to replace or supplement existing infrastructures. In the final part, the dissertation explores the integration of renewable energy into chemical processing networks. As the shift towards lower carbon emissions continues, assessing the impact of variable renewable energy on the profitability and emissions of chemical processing networks is paramount. The developed model investigates optimal decisions concerning renewable energy infrastructure and battery storage. Taken together, this dissertation offers a thorough exploration of network modeling as a tool for optimizing and understanding the increasingly interwoven chemical and refining industries. The models and analyses presented can serve as key resources for stakeholders, policy-makers, and industry practitioners seeking to navigate these industries' future complexities and opportunities.Chemical Engineerin
Why wearing a yellow hat is impossible : Chinese and U.S. Children’s developing possibility conceptions
Full text linkWhen thinking about possibility, one can consider epistemic or deontic principles (i.e., physical possibility or permissibility). Cultures differing in independence and interdependence weigh epistemic and deontic obligations differently; children in these cultures may conceive of possibility differently. A growing body of research on children’s possibility conceptions has consistently replicated a robust finding: though children as young as 4 recognize events that violate physical laws as impossible, these children also deny the possibility of events that are physically possible nevertheless improbable. From ages 4-8, children increasingly acknowledge the possibility of these events (e.g., Shtulman & Carey, 2007). However, these replications have occurred within the U.S. and Canada. The current dissertation takes this research to China, asking whether this pattern holds in an independent culture, and explores potential cultural influences on possibility judgments of ordinary events (i.e., physical regularities), impossible events (i.e., physical violations), and improbable events (i.e., physical irregularities). Study 1 explores the effect of consensus testimony on 8-year-olds possibility judgments in Austin, TX and Wuhan, China. Study 2 explores the developmental trajectory of children’s possibility judgments in Austin and Wuhan, and Study 3 asks whether children from Austin and five different Chinese cities use epistemic constraints to make possibility judgments. This research suggests that culture influences not only what children judge to be possible, but also how children reason about possibility. These findings underscore the complex exchange between culture and cognitive development and reinforce the need for more cross-cultural research with varied populations in diverse locations when studying conceptual development.Psycholog
The influence of music on cognitive function in people with type 2 diabetes
Full text linkPeople with type 2 diabetes (T2DM) are at risk of cognitive impairment. This dissertation aimed to examine how music impacts cognitive function of people with T2DM. A systematic review of people with mild cognitive impairment was conducted to examine the effects of music interventions on cognitive function and to identify gaps in the literature. The systematic review indicated that various music interventions (e.g., dancing, listening to music, musical improvisation) improve global cognitive function, verbal fluency, executive function, and spatial function. The review also highlighted existing gaps in the literature regarding the effects of music interventions on specific cognitive domains and their impact on disease-related cognitive impairment. In addition, secondary analyses on people with T2DM were carried out to investigate the influence of music on their cognitive function. The first study used path analysis to examine the relationships among musical activity engagement, depressive symptoms, physical activity, and cognitive function. The path model revealed that musical activity engagement had a significant indirect effect on subjective cognitive function through physical activity, with physical activity fully mediating this relationship. The second study employed multiple regression to identify the significant musical reward factor predicting cognitive function. Results showed that mood regulation reward had a significant positive association with subjective cognitive function. The findings of the dissertation provide preliminary evidence on the effects of music on cognitive function in people with T2DM. Continued and more rigorous research is necessary to establish strong evidence for the beneficial effects of music and its application in clinical practice. Implications for future research and nursing practice were discussed.Nursin
Regulation of manganese efflux transporter SLC30A10 for maintaining manganese homeostasis
No full textManganese is an essential metal that induces neurotoxicity at elevated levels. Animal studies dating back to the 1920s highlight the importance of hepatic and intestinal manganese excretion for maintaining physiological body manganese levels. However, the molecular mechanism of manganese excretion is only now being elucidated following the discovery of hereditary forms of manganese toxicity linked to homozygous loss-of-function mutations in SLC30A10. Our previous studies identified SLC30A10 as a manganese efflux transporter that is crucial for mediating manganese excretion in the liver and intestines and preventing toxicity. Whereas the disease-causing, yet very rare SLC30A10 loss-of-function mutations are now well characterized, the effects of modest changes in SLC30A10 activity or expression on manganese homeostasis and pathophysiology for general public health are poorly understood. These changes can be caused by genetic factors, such as less severe SLC30A10 polymorphisms, or as a homeostatic response to factors, such as elevated manganese levels. Indeed, several highly frequent, non-coding SLC30A10 SNPs, as well as a coding SNP have been associated with modest manganese level increases, neuromotor deficits, or elevated liver disease markers. In addition, our lab has recently characterized the manganese-induced SLC30A10 upregulation by hypoxia-inducible factors (HIF). This work aimed to build upon these recent findings to: [1] determine the effects of coding SLC30A10 SNP associated with liver disease markers (variant T95I) on SLC30A10 activity; and [2] characterize mismetallation and inhibition of Prolyl Hydroxylase Domain 2 (PHD2) as the homeostatic manganese sensing mechanism that activates HIF signaling and SLC30A10 upregulation. In Chapter 2, liver disease-associated SLC30A10 variant T95I is shown to retain Mn efflux activity comparable to wild-type (WT) SLC30A10 in cell culture assays, suggestive of a minor deficit in SLC30A10 activity that may only present a pathological phenotype in conjunction with other disease factors. In Chapter 3, the mismetallation and inhibition of PHD2 enzyme by elevated manganese are characterized as the homeostatic Mn sensing mechanism that activates HIF signaling and upregulates SLC30A10. Altogether, these results substantially advance our understanding of SLC30A10 regulation in response to elevated manganese and have implications for identifying genetic susceptibilities to manganese pathophysiologies.Cellular and Molecular Biolog
Context Matters. Raising children with a serious condition can sometimes take a toll on a mother’s long-term physical health.
No full textThis study examined how three dimensions of parenting intensity shaped physical health among mothers who care for a child with a serious condition. Fixed-effects modeling of panel data showed all three dimensions predicted poorer health over time. Associations were weaker when mothers had higher incomes or worked for pay.Population Research Cente
Master's thesis recital (mezzo soprano)
No full textVittoria mio core / Giacomo Carissimi -- Thy hand, Belinda ; When I am laid / Henry Purcell -- Che faro senza Euridice / Gluck -- Amorosi miei giorni / Stefano Donaudy -- Der Tod und das Mädchen / Schubert -- Ah! Mon fils! : from Le prophète / Meyerbeer -- Hold fast to dreams / Langston Hughes [text], Rosephanye Powell -- Afraid, am I afraid? : from The Medium / Menotti -- The water is wide / arr. Jay Althouse -- Amoung the fuchscias / Burleigh -- Nobody knows de trouble I seen / arr. Clarence Cameron White -- City called heaven / arr. Hall Johnson -- Memory : from Cats / Andrew Lloyd Webber -- Send in the clowns : from A little night music / Stephen Sondheim -- Gimmie gimmie : from Thoroughly modern Millie / Jeanie Tesori, Dick Scanlan.MusicName of supervisor not provided
N-path filter architectures for radio frequency applications
Full text linkThis research focuses on the design and analysis of N-path filters for radio-frequency applications. A switched-based N-path filter circuit can be employed for filtering an RF signal, as well as a passive downconverter. A known limitation of this filter is that in addition to downconverting signals from around the desired center frequency, the circuit also downconverts signals located around harmonics of the LO frequency. This can degrade the desired signal in the presence of interferers located around these harmonics. Two solutions that address the above limitation are described in this dissertation. First, an N-path filter using a pulse-width modulated representation of a sinusoidal LO to mitigate harmonic downconversion is described. Pulse-width modulated clocks are used to drive the switches in the N-path filter. The potential for employing pulse-width modulation for providing gain control is also described. The architecture is simulated and analyzed in a 65-nm CMOS technology. Second, a downconversion receiver employing a switch-based N-path filter embedded inside a harmonic-selective negative feedback loop is described. A pulse-width-modulated local oscillator (PWM-LO) is used in a feedback-path upconverter to reduce the noise injected by the feedback path circuits around the fundamental frequency of the local oscillator (LO) at the input of the N-path downconverter. While both architectures are effective in reducing the harmonic response, the second approach allows for using lower PWM clock frequency. The feedback-based architecture is implemented, measured and analyzed in a 65-nm CMOS technology. The design is shown to reject the harmonic response of the N-path filter. The compression resulting from blockers around the 3rd and the 5th LO harmonics is also reduced, by 2.3 and 6.9 dB, respectively, while the noise figure is observed to degrade by 2.1 dB through use of the technique. Parasitic capacitance at the input of the N-path filter is known to reduce the gain of an N-path filter while shifting its passband center frequency to a lower value due to residual charge retention at the input node, from one clock phase of the Npath filter to the next. A technique is demonstrated to correct for this source of error. An auxiliary capacitor with alternating polarity is used at the output of the N-path filter to reset the residual charge in the parasitic capacitance in each phase of the N-path filter clock. The auxiliary capacitor is included in the above feedback-based architecture. An N-path architecture with harmonic response suppression which also compensates for the peak frequency shift of the N-path response is implemented, measured and analyzed in a 65-nm CMOS technology. At f [subscript LO] = 500 MHz, peak shift is observed to be 5.5 MHz without compensation, with 2.8 pF auxiliary capacitance, the peak shift reduces to 2.6 MHz, and the noise figure degrades by 1.6 dB. The peak-shift is reduced by 0.7-3.3 MHz depending on the LO frequency with 2.8 pF auxiliary capacitance, while the noise figure is observed to degrade by 0.7-1.7 dB though the use of the peak-compensation technique. Through the use of the above approaches, an N-path filter can be employed as a downconversion receiver with considerably relaxed requirement for harmonic attenuation at the input node.Electrical and Computer Engineerin
Moroccan reef ecosystems : evolution and extinction in the Early Jurassic
Full text linkExtinctions in the Jurassic (201.3-145 million years ago) were foundational to the development of modern marine communities. One of the most severe reef collapses of the Phanerozoic is associated with two consecutive extinctions in the Early Jurassic: the Pliensbachian/Toarcian (Pl/To) boundary event and the Toarcian Oceanic Anoxic Event (T-OAE). This dissertation uses fossil data from Pliensbachian and Toarcian reef sites to reconstruct the ecology of reefs from intervals surrounding these two events to identify variability in how taxa responded to each biotic crisis. These data were used to determine if those differences could be explained by differing extinction drivers in each event. These reefs grew in tropical carbonate settings in the Central Atlas Basin, Morocco; an interval uniquely expanded, enabling us to thoroughly sample reefal units from multiple locations, chronostratigraphic units, facies, and stages of reef growth, from across the Lower Jurassic. A quantitative analysis of more than 250 thin sections provides data for an assessment of the specific structural and ecological changes that occurred as reefs evolved across the Pl/To and the T-OAE. Occurrence and percent composition data were used to quantify the differences in reef facies between extinctions. During the Pliensbachian, lithiotid bivalve reefs grew in lagoonal environments and coral, sponge, and microbialite reefs grew on the platform edge. An influx of nutrients and siliciclastics just after the Pliensbachian/Toarcian boundary caused a collapse of reef ecosystems. In the earliest Toarcian, lithiotids recovered more rapidly than other reef builders, which led to a shift in reef type to predominantly lithiotid biostromes immediately following the recovery of the carbonate factory. Coral, sponge, and microbial reefs were slower to recover from the Pl/To, but showed signs of reestablishment just before the onset of the T-OAE. The environmental changes associated with the T-OAE, such as siliciclastic influx and ocean acidification, resulted in the extinction of the lithiotids; in contrast, corals and microbialites recovered quickly, and coral and microbialite-dominated reefs returned to the platform within the interval of the T-OAE carbon isotopic excursion. This dissertation highlights the differential response of reef framework builders to Jurassic environmental changes and emphasizes that by understanding how past reefs responded to these changes, we can better protect modern and future reefs.Earth and Planetary Science
Worthy of safe haven : the politics of asylum in contemporary Brazil
Full text linkForced displacement worldwide has reached over 65 million for the first time in history. One in every 113 people on the planet is now an asylum seeker, refugee, or internally displaced. The current era demands our critical attention to forced migration in general, but also to asylum in particular. In 2015, two million people applied for asylum—more than any previous year on record. Under international law, asylum seekers are those who claim refugee status after migrating. Yet, as we know, refugee status is not freely chosen but decided by the state. Taking the case of Brazil, this dissertation asks: How does the state determine who qualifies for refugee status, and with what consequences? While there were 966 asylum applications in Brazil in 2010, this number reached almost 29,000 in 2015. Through 15 months of ethnographic fieldwork conducted inside the asylum apparatus, this study traced the perceptions, actions, and interactions—of and between state, civil society, and asylum-seeking actors—that lead to case decisions and constitute the refugee regime in Brazil. Research also entailed interviews, and analyses of asylum case documents and a case decision dataset. This dissertation investigates the logics of the refugee regime in Brazil. It argues that a series of thus-far-uncharted cognitive frames and epistemic practices are crucial to how asylum officials make sense of asylum seekers and evaluate their claims. Moreover, it asserts that the logics of refugee protection are racially configured and configuring by detailing the production of asylum seeker racial legibility and the racial inequalities that result. Finally, it contends that the confusing, piecemeal, and Janus-faced nature of the asylum process produces apathy about refugee status for those who seek and obtain it. In sum, this dissertation contributes to our understandings of the everyday workings of refugee status determination, and the consequences for those seeking safe haven.Sociolog
Exposure to little cigar/cigarillo marketing at the point-of-sale and use of little cigars/cigarillos and cigarettes among young adults
Full text linkIntroduction: There are little to no studies investigating the impact of objectively measured exposure to little cigar and cigarillo (LCC) point-of-sale (POS) marketing at tobacco retail outlets (TROs) on tobacco use. The aim of the present study was to examine the relationship between objectively measured exposure to LCC POS marketing and current and future use of LCCs and conventional cigarettes. Method: Data from the Marketing and Promotions Across College in Texas (Project M-PACT) study were used in the present study. Participants were 4,201 Texas young adults attending 24 Texas colleges. All LCC marketing at TROs within one mile of each of the 24 colleges was objectively documented and linked to the survey data. Separate multilevel logistic regression analyses examined the impact of LCC marketing at the POS on current and future (six months later) use of LCCs and cigarettes. All analyses controlled for age, sex, race/ethnicity, and type of college, and longitudinal models controlled for baseline use Results: Findings from cross-sectional analyses indicated that greater exposure to LCC POS marketing is associated with higher odds of current use of LCCs (AOR = 1.003, 95% CI = 1.0002, 1.0053) and cigarettes (AOR = 1.006, 95% CI = 1.0050, 1.0075). Specifically, for each additional piece of LCC marketing material observed, the odds of current LCC use increased by a factor of 1.003 and current use of cigarettes increased by a factor of 1.006. These findings did not hold in the longitudinal models. Exposure to LCC POS marketing at baseline predicted current cigarette use at 6-month follow-up, specifically, for each additional piece of LCC marketing material observed, the odds of current LCC use increased by a factor of 1.004. However, exposure to LCC POS marketing did not predict current LCC use at 6-month follow-up. Conclusion: Results demonstrated that exposure to LCC POS marketing is associated with higher odds of current LCC use as well as current and future cigarette use among young adults. This suggested a significant influence of LCC marketing exposure at the POS. Regulations on LCC POS marketing, especially around college campuses, should be considered.Kinesiology and Health Educatio