Cornell Theses and Dissertations
Permanent URI for this collection
The theses and dissertations of graduate students at Cornell University have been deposited in Cornell's institutional repository (eCommons) since about 2004. This collection also includes a few earlier Cornell theses.
Students retain ownership of the copyright of their work. Students also have the option of imposing a temporary embargo on access to the full text of their theses for limited amount of time (see eCommons access policy). If access to a thesis is restricted, the metadata record for the thesis is still visible, but the text "Access to Document Restricted" is displayed, and a field labeled "No Access Until," which indicates the date when the full text of the thesis will become accessible.
More information about finding Cornell theses and dissertations is available on this library guide, and the eCommons help page for finding content in specific collections, including theses and dissertations.
In general, older theses and dissertations from Cornell University are not currently available as digital files in eCommons. The Library is willing to digitize and make available older Cornell theses on a cost recovery basis. If you are interested in this service, please contact dcaps@cornell.edu.
Browse
Recent Submissions
Item WRITING ROADS: WORKER STORYTELLING, KARMIC HAUNTING, AND THE MANAGEMENT OF CONSTRUCTION IN CHINAWang, Yuanping (2020-08)On the edge of a sparsely-populated area in China’s countryside, a young worker with an excavator was shoving an unclaimed corpse out of the way of a highway under construction. Afraid of being seen by the nearby villagers, he hastily mixed the bones with trash and then dumped them a mile away under cover of night. It was not until later, when the worker died during construction, that the story of the corpse turning into a ghost and asking for the worker’s life, circulated in the field. Faced with the daily hazards of poorly regulated labor, workers tend to dramatize accidents, relating them to relocated corpses, disturbed animal dwellings, or old trees growing in tomb dirt. To workers, these ghosts haunt the construction; therefore, a machine malfunction must be redressed by local rituals, a coworker’s death may be a sacrifice for the moral insult to the land, and a bossy manager’s death is a divine punishment for the state’s disrespect of workers. Attending to Chinese workers’ affective responses to death, infrastructure, history, landscape and state power, this thesis aims to explore how ghosts speak to Han migrant workers in Xinjiang as they adjust to ever-expanding, dangerous, and sometimes fatal infrastructure projects by engaging not only with one another, but also with supervisors, local bureaucrats, company managers, and ritual specialists who actively participate in the construction.Item ENABLING STABLE LITHIUM NUCLEATION AND GROWTH VIA CROSSLINKED POLYMER ELECTROLYTES AND ELECTRODE/ELECTROLYTE INTERPHASESStalin, Sanjuna (2021-05)The rapid rise of electric drive vehicles has accelerated research aimed at developing energy storage technologies with high gravimetric and volumetric energy densities. Lithium metal batteries (LMBs) are considered particularly important in this aspect but are not available today primarily because the lithium metal anode poses multiple challenges. Among them, the most difficult include the metal’s propensity to form an undesirable and dynamic corrosion layer known as the solid electrolyte interphase (SEI) that results in rough, non-planar electrodeposits at all current densities. These challenges arise from coupling of chemical reactivity of Li, highly reducing potentials during battery charge, and the out-of-equilibrium transport phenomena that drive morphological instabilities at the metal/electrolyte interface. In this thesis, crosslinked polymers are used as a powerful platform to develop design principles for electrolytes and electrode/electrolyte interphases that enable planar deposition in lithium metal anodes. The design principles are based on guidelines from a theoretical linear stability analysis of metal electrodeposition that captures chemical effects in the transport coefficients and their spatial variations at the electrolyte-electrode interphase. The aim is then to probe physical factors responsible for the nucleation and growth of morphologically unstable electrodeposits. During dendrite growth, it is revealed that the growing deposit front experiences a significant amount of compressive stress exerted by the bulk electrolyte, which if large enough can potentially slow down the growth rate. Development of structured electrolytes capable of increasing this compressive stress, while not yielding under compressive strain is proposed and demonstrated as an effective strategy to suppress dendrite growth. To address dendrite nucleation, artificial interphases and similar electrode engineering techniques are proposed as a potential drop-in solution. Careful design of the solid electrolyte interphase and tuning of its chemistry and physical properties are found to be crucial for driving stable nucleation of lithium electrodeposits. In particular, strategies to synthesize and fabricate electrochemically stable artificial interphases with precise thickness control are shown to be essential for achieving uniform ion transport, for enhancing surface tension forces, and for reducing the equilibrium reduction rate at the metal surface. Importantly, these methods enable planar lithium electrodeposition in both nucleation and growth stages.
Item Group Versus Individual Variations in the Narrative Content of College Student Autobiographical MemoriesBraimon, Rebecca (2022-08)Autobiographical memories (AM) are a subset of memories that pertain specifically to events in an individual’s own past. Using simple predictor models, this paper perturbed the narrative content of 117 Cornell students’ positive and negative autobiographical memories about parents and peers, exploring whether or not group-level status markers like sex and culture were significant predictors of recall style. Specifically, we wanted to validate or expand upon previous research on group versus individual-level differences in memory. Through mixed models statistical analysis of the 468 memories in our final dataset, we found that group membership accounted for less of the variation in AM recall than expected, with individual-level subject differences being much more pronounced. Of the narrative content variables analyzed, participant sex only significantly predicted three –agency, emotional expressiveness, and chronology– and participant culture/ethnicity only significantly predicted two –redemption and unity. The implications of these findings, as well as the methodological limitations that might have prevented us from parsing more group differences, are discussed. Suggestions for future study replications that might yield more generalizable results are mentioned.Item Self-Timed Length-Adaptive ArithmeticBingham, Edward Arthur (2020-12)Diminishing returns in technology scaling has motivated a resurgence of exploration into new computer architectures. While Coarse Grained Reconfigurable Arrays show promise in accelerating commonly used complex operations, their overall capacity remains fairly limited. While there is pressure on general purpose systems to support wide operations, the typicalworkload mostly exercises the lower 10 to 15 bits. This leaves most of the array on and unused during normal operation. This thesis presents adaptive digit-serial arithmetic as a plug-and-play method to support a variety of bitwidth requirements, showing decreased energy and area alongside increased throughput.Item Alternative Antimicrobial Agents Against Multidrug-Resistant Gram-Negative BacteriaO'Leary, Meghan Kathleen (2022-08)The emergence of antibiotic-resistant bacteria is outpacing the discovery and development of new antibiotics, and this phenomenon poses a global health crisis and exemplifies the need to develop alternative antibacterial strategies. Oligothioetheramides (oligoTEAs) are a class of synthetic, sequence-defined oligomers that have demonstrated antibacterial activity against both gram-positive and gram-negative bacteria. Particularly, the oligoTEA BDT-4G has exhibited potent activity against a range of multidrug-resistant Pseudomonas aeruginosa isolates. In addition, BDT-4G can evade mechanisms conferring resistance to the last resort antibiotic, polymyxin B, and is active against P. aeruginosa clinical isolates with an acquired resistance to polymyxin B, as well as intrinsically-resistant gram-negative species, such as Burkholderia and Pandoraea spp. However, BDT-4G is toxic to mammalian cells at concentrations required for bactericidal activity, and this narrow therapeutic window precludes clinical translation. To mitigate cytotoxicity, we first investigated a bacteria-responsive prodrug methodology whereby BDT-4G is temporarily inactivated through coupling to a polyethylene glycol (PEG) promoiety via a triglycine peptide linker (Gly3). PEGylation of BDT-4G decreases the in vitro cytotoxicity by an order of magnitude, and antibacterial activity is recovered via site-specific cleavage of the triglycine linker by LasA, a virulence factor secreted by P. aeruginosa. To further improve localization to the infection site for systemic applications, we next explored an antibody-bactericide conjugate (ABC) platform for the targeted delivery of BDT-4G. In this design, BDT-4G is coupled via a cleavable linker to an antibody that targets P. aeruginosa. For proof-of-concept of this ABC platform, we first coupled the prodrug, PEG-Gly3-BDT-4G, to an anti-Pseudomonas polyclonal antibody, and we demonstrate LasA-mediated release of the payload and bactericidal activity against P. aeruginosa. Lastly, to improve the reactivity of the ABC, we conjugated BDT-4G to the monoclonal antibody Cam-003, which binds to the conserved P. aeruginosa exopolysaccharide Psl. This conjugation was achieved through a host-cleavable peptide linker, which was selected to offset the selection pressures that may accompany a therapeutic that is activated by bacterial proteases. Through flow cytometry, fluorescence resonance energy transfer, and time-kill curves, we have demonstrated that the ABC binds to the bacterial cell surface, serum cleaves the linker, and the released oligoTEA payload is bactericidal. Overall, these studies validate the ABC strategy in vitro and motivate the translation to in vivo experiments.Item Do Formal Workers Use Informal Search Methods? Investigating Labor Search in Mexico.Zhong, Moira (2022-12)This study examines how formal sector employment affects the worker’s job search methods in Mexico. It studies how each worker and workplace characteristic is associated with the probability of using each job search method as opposed to private/public agencies using a multinomial logit model. It also examines a differential effect of using friends and family search in different sizes of town: the bigger the size of town, the more rewarding is friends and family search in terms of real monthly wages, and the possibility that the position offers any work-related benefits. In addition, it finds that using formal job search methods such as friends/family search, advertisement, internet search is associated with a slightly larger probability of that position being in the formal sector for males than females, while using direct approach is associated with a significantly larger probability of that position being in the formal sector for females than males. Importantly, it argues that the return to searching through friends and family is bigger in terms of real monthly income in towns of smaller sizes, even though larger towns are associated with higher real monthly income.Item Sustainable thinking in a digital eraZhao, Xiaobai (2022-12)This essay explores current environmental problems within the context of the digital age. By using several studios and elective works in MS.AAD program at Cornell as case studies, the essay connects environmental issues in urban and building scales to innovative strategies supported by emerging digital tools. The topics include scenic site water pollution, metropolitan electricity system transformation, sea level rising and flooding mitigation, water treatment, adaptive material reuse, sustainable timber customization, and urban evacuation plans.For each topic, the essay evaluates optimal design strategies through robust research and analysis. By implementing digital technologies like immersive animation engines, 3D printing, robotic arm fabrication, and interactive infographics, the projects tend to explore new territories of sustainable thinking in the architecture industry. Here, solving or mitigating environmental problems is not the only valuable sustainable design practice. Building awareness of hidden pollution is sustainable thinking. Encouraging people to play a role in the energy system through virtual games is sustainable thinking. Digitally modeling carbon footprint in building assembling and disassembling processes is sustainable thinking. Utilizing renewable natural building materials in digital fabrication is sustainable thinking. Even providing critical information about security and food services is sustainable thinking. With speculative graphic representation and small-scale fabrication prototypes, the essay bridges these innovative perceptions of sustainable design with the current digital context. It not only wants to challenge our status quo on sustainability but also aims to transform our understanding of digital technologies. If the first industrial revolution started the chapter of serving climate and environmental change, can we, with the help of the new technology revolution, mitigate or even alter the problems? Following the case study, are eight studio and elective projects the author worked on in her MSAAD program. More detailed documentation and explanations for each case study can be found in this section. A few of the projects also concern with sustainable design and development but are not selected due to a more conventional design approach.Item Time in the minds of Spaniards and Moroccans: Evidence from spontaneous gesturesZhao, Siyi (2022-12)People use space to conceptualize time, but the specifics of the space-time mappings in people’s minds vary across cultures. Here we investigated whether people with different reading and writing systems in their native languages think about time differently, and whether exposure to a new language and culture changes people’s space-time mappings. We analyzed the spontaneous hand gestures that people made while telling stories about the past and the future and compared these gestures across three groups: Spaniards living in Spain, Moroccans living in Spain, and Moroccans living in Morocco. Whereas Spanish is written from left to right, Moroccan Arabic is written from right to left. Consistent with previous studies linking temporal thinking with reading and writing habits, we found that Spaniards showed a statistically significant bias to gesture leftward for earlier times and rightward for later times. Moroccans showed the opposite bias, gesturing rightward for earlier times and leftward for later times; this pattern did not differ significantly between the Moroccans living in Morocco (who were speaking Moroccan Arabic during the test) and the Moroccans living in Spain (who were speaking Spanish during the test). Together, these results support that hypothesis that people’s mental timelines follow the direction of reading and writing in their native languages, and that these culture-specific space-time mappings can be maintained despite immersion in a second language and culture.Item A MULTI-STAGED STOCHASTIC OPTIMIZATION MODEL WITH COLUMN GENERATION BASED HEURISTICS FOR HOSPITAL EVACUATIONS DURING HURRICANESZhang, Qian (2022-12)Perpetual hospital evacuations caused by hurricanes require well-informed decision makings to handle uncertainty in future conditions and scarcity in various resources. Simultaneous evacuations from multiple hospitals are more challenging due to additional complexity in evacuation route choices and coordination among both evacuating and receiving hospitals. This thesis addresses above issues by developing a multi-staged stochastic optimization model and column generation based heuristics that considers uncertain future flood, wind and road traffic conditions, limited staff and vehicle resources, and effectiveness of evacuation routes generation. The model determines patient evacuation schedule and corresponding evacuation routes while trading off risk and cost. A comprehensive case study on North Carolina hospitals with Hurricane Isabel is conducted with data and model outputs of previous research. The results highlight the benefits of the model formulation and the heuristics that effectively generates complex evacuation routes and coordinates evacuating hospitals’ efforts while adapting to new information.Item On Spatial Ecologies of Culture: Reciprocal Constituents of the Built EnvironmentYocum, Connor (2022-12)Place, a scaleless realm of territory in which architecture performs, cannot be understood as a purely physical context. It cannot be divorced from temporal effects of time nor the ideological concerns of other actors. The contexts in which architecture exists are constructed from an interconnected ecology of people, place, and time that manifest complex notions of culture in space. The following body of work seeks to understand architecture as a reciprocal medium that engages with complex inputs across the physical and nonphysical terrain in which it acts, while at the same time becoming an input itself, embedding the practice with agency. This study positions architecture as a dynamic force in a spatial ecology and explores through three lenses how the practice simultaneously represents and refigures the cultural: Situations, Dissimulations, and Dispositions.