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Properties of topological semimetals and altermagnetic materials using electronic structure calculations
No full textJanotti, AndersonQuantum materials have emerged as promising candidates for the latest technological advancements. Among the key areas of focus are topological materials and unconventional magnetic materials. This thesis explores the potential for understanding and controlling the electronic and magnetic properties of these materials. ☐ In the initial section of the thesis, we provide an overview of fundamental concepts of topology in materials science and introduce a recently identified phase of collinear magnetism known as altermagnetism. We also present representative material classes, including rare-earth monopnictide (RE-V) as an example of topological materials and antiferromagnetic materials possessing the rutile structural motif, exemplified by ruthenium dioxides RuO, with an emphasis on its debated magnetic properties, as an example of altermagnets. This is followed by a brief description of the theoretical methodology employed in our simulations, specifically the Density Functional Theory. ☐ The main content of the thesis begins with semimetallic RE-V compounds, where we demonstrate that their electronic structures can be tuned via structural perturbations such as strain and dimensionality reduction. This is achieved by utilizing a detailed understanding of their electronic structures, especially those near the Fermi level. Interestingly, we also show that these perturbations can ultimately modify their band topology, opening new possibilities for controlling their use in electronics and spintronics. ☐ Subsequently, we shift our focus to altermagnets, a novel class of collinear magnetic materials where the unique arrangement of non-magnetic ligands around magnetic entities contributes to their distinctive spin-group symmetry. This symmetry enables anisotropic exchange interactions, thereby inducing spin-splitting along specific high-symmetry momentum directions in the Brillouin zone despite the absence of net magnetization. RuO2 in its rutile structure serves as a candidate for such behavior. Recent experiments, however, have challenged earlier conclusions about its magnetic structure, raising questions about the origin of magnetism in the material. Interestingly, we demonstrate that spontaneous surface magnetization, as a possible contribution to the magnetic property of RuO2, can develop on the (110) surface of the material due to the breaking of local symmetry at the surface, leading to spin-polarization effects. The significance of this surface magnetization as a relevant source of magnetism and its role as a potential explanation for conflicting experimental results are discussed.University of Delaware, Department of Materials Science and EngineeringPh.D
A transaction-cost model of chronic specie scarcity and the evolution of monetary structures in constrained colonial economies
No full textThis article was originally published in Cliometrica. The version of record is available at: https://doi.org/10.1007/s11698-025-00304-y.
© The Author(s) 2025.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.A transaction-cost model of monetary choice is used to justify colonists’ claims that specie money for executing within-colony trades and paying local taxes was chronically scarce in Britain’s pre-nineteenth century North American colonies. This scarcity is shown to be the result of individual rational maximizing choice behavior given the constraints imposed on the colonies by their mother country. By contrast, the conventional quantity-theory-of-money, specie-flow model indicates that a chronic specie scarcity equilibrium is impossible. Implicit assumptions in the quantity-theory-of-money model are shown to not apply to these colonial economies. The transaction-cost model developed here builds on the Walrasian–Arrow–Debreu general equilibrium model by incorporating transaction costs and media-of-exchange structures into the market clearing mechanism. Specie (outside money) and non-specie-money media-of-exchange structures (inside monies), which have differing transaction costs, are added to the model. Those additions, along with import substitution and trade-control constraints, identify the plausible circumstances that yield a chronic specie scarcity outcome in a colony. Whether the individual rational maximizing monetary choices that produce chronic specie scarcity in a colony lead to sub-optimal or to optimal social welfare outcomes in that colony depends on what non-specie media-of-exchange structures emerge as the inside money in that colony.Preliminary versions were presented at the Third European Congress on World and Global History, London School of Economics, London, UK, 14-17 April 2011; The Institute for Global Law and Policy Pro-Seminar on Re-Theorizing Liquidity, Harvard Law School, Cambridge, MA, 6-9 June 2011 and 2 June 2012; the Conference on “De-Teleologising History of Money and Its Theory,” Japan Society for the Promotion of Science Research—Project 22330102, University of Tokyo, 14-16 February 2012; University of Delaware, 11 October 2012; Allied Social Science Associations Annual Conference, San Diego, 5 January 2013; and the conference on “Money as a Democratic Medium,” Harvard Law School, Cambridge, MA, 14-15 December 2018; Conference on “Money in Vast Early America,” sponsored by the University of Southern California, the Huntington Early Modern Studies Institute, and the William and Mary Quarterly held at the Huntington Library, Pasadena, CA, 9 Dec. 2023. The author thanks the participants of these conferences and Christine Desan, Alejandro Komai, Akinobu Kuroda, and Angela Redish for helpful comments. This article honors the influence of Douglass C. North whose graduate courses in economic history and property rights I took in the mid-1970s
Collegiate charism: the post-Vatican II architecture of the St. Thomas More Oratory at the University of Delaware
No full textIsenstadt, SandyThe St. Thomas More Oratory has been the spiritual home of Catholic students at the University of Delaware since 1970, and it is also a useful example of vernacular post-Vatican II architecture. This thesis argues that the Oratory’s design was aligned both with local building customs and, most importantly, recent Church teaching following the changes of the Second Vatican Council (1962-1965). The Oratory’s economic use of ornament, radical horizontality, and flexible seating are important artifacts of a period in social and theological flux. While time has demonstrated that it was not as effective at creating a multi-generationally beloved environment of worship as the designers intended, and new church designs are closer to the Gothic and Classical styles that long existed in the Catholic imagination, the Church’s experimentation with Modernism was a sincere and pragmatic attempt at reconciling a millennia-old faith with a changing world.M.A.University of Delaware, Winterthur Program in American Material Cultur
Eat me: voracious appetite and embodiment in surreal fiction
No full textWasserman, Sarah L.This dissertation delineates a new genre of contemporary fiction called “voracious fiction,” which uses the aesthetic conventions of surrealism to subvert cultural ideals about proper femininity. Voracious fiction subverts the violence inherent in American heteropatriarchy through surreal depictions of female embodiment and appetite that emphasize what is monstrous is not female bodies, but rather the cultural forces that turn them into objects to be consumed—visually, sexually, and literally. Voracious fiction blurs the boundaries between literary and genre fiction, realism and non-realism, and challenges audience expectations about these genre conventions, especially the genres of horror and romance. The project considers American fiction (novels, films, short stories, and popular media) produced in roughly the last fifteen years, at the beginning of the 2010s, including Melissa Broder’s Milk Fed (2021), Karyn Kusama’s Jennifer’s Body (2009), Carmen Maria Machado’s Her Body and Other Parties (2017), and Sarah Rose Etter’s The Book of X (2019). This project is about American culture beyond the field of literature, and its relationship to its literature. It brings together scholarly concerns with intersecting popular culture conversations about diet culture, white feminism, and neoliberalism through interludes of public or para-academic essays. These interludes explore the project’s key themes in current affairs and pop cultural artifacts: popular contemporary media about feminist cannibalism, the trend of “clean eating” on Instagram and TikTok, and the self-sabotaging nature of male heterosexual desire.University of Delaware, Department of EnglishPh.D
Linearly scaled-up plasma-water biphasic DBD microreactors: Application to hydrogen peroxide synthesis and water decontamination
No full textThis document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering Copyright © 2025 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/page/4authors/benefits/index.html#articles-request
This article was originally published in ACS Sustainable Chemistry & Engineering. The version of record is available at: https://doi.org/10.1021/acssuschemeng.5c07296
This article is embargoed until November 24, 2026We previously demonstrated that a modular biphasic liquid water/helium plasma reactor can efficiently produce hydrogen peroxide (H2O2). Here we demonstrate that by increasing the reactor length and thus the residence time or the applied plasma power, we can increase the outlet H2O2 concentration in the aqueous phase (an example of 39 mM is showcased) while using an argon plasma. By introducing spatially resolved optical emission spectroscopy (OES), we reveal an increasing water-produced ·OH radical concentration along the tubular reactor and correlate the ·OH production with the H2O2 concentration. High peroxide concentrations achieved through a straightforward linear reactor scale-up are suitable for green partial oxidation reactions and biochemical and environmental decontamination. This potential is exemplified by showcasing the complete and ultrafast continuous flow decolorization of an aqueous solution of highly concentrated (300 mg L–1) methylene blue (MB)
Evaluation of “Difficult-to-Express” Monoclonal Antibodies in a CHO-Based Hybrid Site-Specific Integration System Under Industrially Relevant Conditions
No full textThis article was originally published in Biotechnology Journal. The version of record is available at: https://doi.org/10.1002/biot.70102
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work
is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2025 The Author(s). Biotechnology Journal published by Wiley-VCH GmbH.Variation in the primary sequence of monoclonal antibodies (mAbs) can negatively affect their behavior in biopharmaceutical
manufacturing platforms, and efforts to identify mAbs with poor “developability” characteristics lack robust methods for assessing
mAb expression from an industrially relevant platform. Recent advancements in site-specific integration-based (SSI) platforms in
Chinese hamster ovary (CHO) cells can mitigate the high transcriptional variation observed with random integration and the
low industrial relevance of transient expression by providing a flexible platform for mAb expression from a consistent clonal
background. This work applies a novel SSI-based expression system capable of generating isogenic cell pools in less than 1 month
to systematically compare the expression of ten sequence variants of two therapeutically relevant mAbs from two genomic loci
under industrially relevant culture conditions. Eight single amino acid mutations in trastuzumab resulted in reduced productivity
compared to the wild-type mAb in batch cultures, and three mutations maintained a low-expressing phenotype in fed-batch
cultures. The mutations resulted in variant-specific patterns of decreased domain stability and increased ER stress. The application
of industrially relevant SSI systems in developability workflows could strengthen the understanding of the sequence determinants
of mAb expression to improve mAb design, candidate selection, and process development decisions.This research was supported by the National Science Foundation under grants 1624698 and 2100502, and in part by the financial assistance award
70NANB17H002 from the U.S. Department of Commerce and National Institute of Standards and Technology
CHARACTERIZATION OF CELL-MIMETIC DRUG CARRIERS FOR SUSTAINED DELIVERY OF THERAPEUTICS
No full textGleghorn, JasonMetastatic cancer is a challenging disease to treat. One contributing factor to consider is the selective permeability of the lymph nodes, which enables them to act as a safe haven for cancer cells in the body. One approach is to utilize a Trojan horse strategy, where cryo-shocked T-lymphocytes (CSTLs) act as an engineered cell-mimetic drug carrier to home to the lymph node. CSTLs loaded with small-molecule drugs resulted in rapid release kinetics, which limited achievable doses at the target sites.
To follow on, it was hypothesized that by incorporating a hydrogelated core into the CSTLs system, modifying the CSTLs would provide controlled, delayed, sustained release of the therapeutic agents. This version of the carriers is called hydrogelated T-lymphocytes (HTCs), utilizing DOX-laden poly(ethylene glycol)-based gelation solution (PEG-diacrylate (PEG-DA), initiated with 2-hydroxy-4'-(2-hydroxyethoxy)-2 methylpropiophenone).
Three aims were researched for the hypothesis: (1) characterization of loading efficiency and max loading of CSTLs and HTCs, (2) determination of the release kinetics of CSTLs and HTCs loaded with Doxorubicin, and (3) test target efficiency of loaded drugs against cancer cells in vitro.
To characterize loading efficiency and max loading of CSTLs and HTCs, the ability for HTCs to be loaded with doxorubicin had to be assessed, both visually with an epifluorescence microscope and utilizing a plate reader. The CSTLs have an average loading efficiency of 74.27 ± 6.61%. 10% and 20% PEG-DA in HTCs had average loading efficiencies of 3.95 ± 3.42% and 28.76 ± 10.52%. When testing for maximum loading, respectively for each concentration 0.525 mg/ml, 0.7 mg/ml, and 0.8 mg/ml, the efficiencies were 3.95 ± 3.42%, 12.93 ± 3.42%, and 17.19 ± 2.25%. This aim helped to better understand the loading efficiencies of HTCs and how to increase their loading abilities.
To investigate the release kinetics of CTSLs and HTCs, release experiments of all drug delivery vehicles were completed. The release profiles were analyzed utilizing one and two-phase decay, and the rates of release were determined, after varying controlled release compared to CSTL’s rapid release. Both 20% and 10% PEG-DA HTCs drug delivery vehicles have similar trends, exhibiting one-phase decay graphs. 10% PEG-DA HTCs have a rate of release (K=1.16*102), whereas 20% PEG-DA HTCs have a lower rate (K=7.87*10-5). The 20% PEG-DA HTCs have a higher percentage released than the 10% PEG-DA HTCs. With a lower loading efficiency, the 20% PEG-DA has less to release than the 10% PEG-DA HTCs.
To test the target efficiency of the HTCs loaded with the drug, the loaded HTCs were tested on 4T1s cancer cells. An assay was run to determine the viability of the cancer cells to see how efficiently the drug-loaded vehicles treated them. The viability of the 4T1s on the bottom of the well was analyzed after 20% PEG-DA HTCs released DOX from a transwell directly on the 4T1s. The viability of the 4t1's was 90.7 % after 7 days, compared to the positive and negative controls, which were respectively 100% and 58.5%.
This study demonstrated that the encapsulation of small-molecule drugs inside a hydrogel core (HTCs) produced a drug delivery vehicle with tunable properties that will enable a delayed and controlled release of small-molecule payload. This study supports the hypothesis that incorporating a hydrogelated core into the CSTLs system would provide controlled, delayed, sustained release of the therapeutic agents. This new delivery system potentially creates formulations that enable sustained release of therapeutics locally within the lymph node. Optimizing the amount of drug at the site of the disease, decreasing dosing frequency, and less off-target accumulation leads to lower systemic toxicity for the patient.Senior Thesis Progra
Essays on well-being
No full textTobacman, JeremyThis dissertation comprises two essays on the relationship between public policy and individual well-being. The first chapter investigates the causal impact of the Earned Income Tax Credit (EITC), one of the largest U.S. antipoverty programs, on subjective well-being (SWB), measured by self-reported happiness and life satisfaction, using two quasi-experimental strategies. I exploit variation in state-level EITC supplements over time and construct a simulated instrumental variable to estimate the effect of net income on SWB, accounting for potential labor supply endogeneity. Leveraging federal and state policy changes that vary by family structure, I find that while the EITC significantly increases household income, its effects on SWB are mixed. A $1,000 increase in generosity modestly raises SWB, especially during peak tax refund months, whereas increases in net income alone do not consistently improve SWB. ☐ The second chapter examines the impact of state-mandated financial education on adult financial well-being (FWB), using variation in the timing and intensity of high school curriculum requirements across U.S. states. Drawing on repeated cross-sectional data from the National Financial Capability Survey (NFCS) and a composite FWB measure, I employ a staggered difference-in-differences framework and event study design. The results show no overall evidence that mandates affect FWB. While mandate intensity (course, test, or both) yields no significant effects, requiring a course alone has a statistically significant positive impact.University of Delaware, Department of EconomicsPh.D
Aldehyde Electrophilicity and Ring Strain Govern Xylose Acetalization Pathways for Biobased Chemical Production
No full textThis is an open access article under the terms of the Creative Commons Attribution License, https://creativecommons.org/licenses/by/4.0/ which permits use, distribution and reproduction in any medium, provided the original work is properly cited.© 2025 The Author(s).
This article was originally published in Chemistry-Sustainability-Energy-Materials. The version of record is available at: https://doi.org/10.1002/cssc.202501562Xylose acetalization has emerged as a potent tool to extract this sugar from lignocellulosic biomass and for creating new biobased chemicals and materials. This article elucidates a generalized reaction network for xylose acetalization and reveals the role of aldehyde electrophilicity and ring strain in intermediate formation. Aldehydes with strong electrophilicity stabilize xylose as both furanose- and pyranose-monoacetals, whereas weaker aldehydes favour xylofuranose acetalization due to the high ring strain in pyranose acetals. The energetically favoured furanose diacetals dominate the product distribution over extended reaction time regardless of aldehyde types and reaction pathways. Measurements of the xylose tautomer ratio in the reaction conditions highlighted the importance of xylose isomerization in forming furanose acetals. These mechanistic insights not only explain the evolution of reaction intermediates but also aid in identifying potential products for sustainable chemical synthesis.This work was supported by NCCR Catalysis (180544); National Centre of Competence in Research; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (TMCG-2_213835)
An approach to predicting linear trends in tagging-related mortality and tag loss during mark-recapture studies
No full textThis article was originally published in Frontiers in Ecology and Evolution by Frontiers Media. The version of record is available at: https://doi.org/10.3389/fevo.2025.1572994.
© 2025 McCutcheon, Campbell, Hudock, Motz, Windsor, Carlisle and Hale. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) (http://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Using tags within a mark-recapture framework allows researchers to assess population size and connectivity. Such methods have been applied in coastal zone habitats to monitor salt marsh restoration success by comparing the movement patterns of Mummichogs (Fundulus heteroclitus) between restored and natural marshes. Visible Implant Elastomer (VIE) tags are commonly used to tag small fish like Mummichogs, though the retention and survival of small fish using this method varies between studies, producing uncertainty during mark-recapture-based approaches. To address this, we conducted a laboratory experiment to determine the rate of tag loss and mortality of VIE tags on Mummichogs of two size classes (greater or less than 61 mm) and across different taggers. Tag loss and mortality increased over time, and the latter significantly varied between taggers. We then developed a predictive model, R package ‘retmort’, to account for the effect of this increase on mark-recapture studies. When adapted to a series of published works, our model provided rational estimates of tagging error for multiple species and tagging methods. Of the case studies the model was applied to (n = 26), 15 resulted in a percent standard error greater than 5%, signaling a significant percent of error due to uncounted, tagged animals. By not accounting for these individuals, recapture studies, particularly those that assess restoration efforts and coastal resilience, could underestimate the effects of those projects, leading to superfluous restoration efforts and erroneous recapture data for species with low tag retention and high mortality rates.The author(s) declare that financial support was received for the research and/or publication of this article. This material is based upon work supported by the US Army Corps of Engineers, ERDC Contracting Office under Contract No. W912HZ-22-2–0015 and student support was provided by the National Science Foundation (NSF-OCE) Research Experiences for Undergraduates Award (#2051069)