University of Illinois Urbana-Champaign
Illinois Digital Environment for Access to Learning and Scholarship RepositoryNot a member yet
123813 research outputs found
Sort by
Using Advanced Binder Rheological Parameters to Predict Cracking Potential of Hot-Mix Asphalt Mixtures with Modified Binders
No full textThis study provides insights into the complexities of asphalt binder modifications and their impact on hot-mix asphalt (HMA) cracking potential. An experimental program was developed to assess the cracking potential of HMA from binder characteristics. Various binder types, including polymer-softener-modified binders, were considered. Rheological tests were performed on binders at short- and long-term aging conditions. A multiple stress creep recovery test was conducted to evaluate the stress-dependent rutting potential of binder blends, while Fourier-transform infrared spectroscopy was used to evaluate oxidative aging and polymer degradation of the binder. Rheological parameters of binders were used to predict HMA cracking potential utilizing test results of the Illinois Flexibility Index Test. Statistical analyses, primarily based on multi-linear regression, were used to develop predictive models linking binder rheological properties to HMA cracking potential. The HMA flexibility index (FI) was predicted using the following binder rheological parameters: creep stiffness at 60 s (S-value), rate of stress relaxation at 60 s (m-value), asphalt binder content (BC), asphalt binder replacement (ABR), number of design gyrations (Ngyr), and Δ|G*|peak τ. For simplicity, short- and long-term aged HMA FI prediction models are based on S-value, m-value, and ABR. Three uncertainty categories of predicting FI from binder rheological parameters are introduced. The categories are associated with binder acceptance based on potential cracking risk.IDOT-R27-25
Comments on “Targeted consultation in preparation of the COMMISSION GUIDELINES TO CLARIFY THE SCOPE OF THE OBLIGATIONS OF PROVIDERS OF GENERAL-PURPOSE AI MODELS IN THE AI ACT” (2024/1689; ‘AI Act’)
No full textThese comments address the public opportunity to provide input on “Targeted consultation in preparation of the COMMISSION GUIDELINES TO CLARIFY THE SCOPE OF THE OBLIGATIONS OF PROVIDERS OF GENERAL-PURPOSE AI MODELS IN THE AI ACT” (2024/1689; ‘AI Act’). With the expanded development and use of general-purpose AI (GPAI) models, we believe clear guidance on compliance with EU rules, supported by empirical research insights, is critical to the public interest
Searching for new physics with Fermilab’s proton beam
Get PDFSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Diana Forbes, accepted the attached license on 2025-05-06 at 15:03.The student, Diana Forbes, submitted this Dissertation for approval on 2025-05-06 at 15:15.This Dissertation was approved for publication on 2025-05-19 at 13:23.DSpace SAF Submission Ingestion Package generated from Vireo submission #22236 on 2025-10-20 at 16:57:02In this thesis, I summarize my work on two projects that use Fermilab's proton beam to search for new physics. The first project was in response to the anomalous muon magnetic moment announcement in 2021~\cite{Muong-2:2021ojo}. This project proposed that we can use the SpinQuest experiment \cite{apyan2022darkquestdarksectorupgrade}, with no additional installations needed, to look for a muonphillic scalar particle whose coupling to muons could resolve the anomalous muon magnetic moment. In this setup, a 100 GeV proton beam would travel through a thick target material to produce a muon beam through scattering off of the target nuclei. This muon beam would then traverse the last length of the target, estimated to be cm of material, to radiatively produce hypothetical scalar particles that would promptly decay into a muon pair. Hence, the signature would be an event with a pair of muons that has an invariant mass equal to the mass of the scalar particle. We simulated events for a choice of muons on target (MOT) with typical energies of 20 GeV, and, with a invariant mass resolution, this strategy can probe the entire parameter space for which 200 MeV -- GeV scalar particles resolve the muon anomaly. Ultimately, we estimated that we would only need about 6 years of beam time to achieve a discovery sensitivity. For the second project, I collaborated with a group member named Rachel Nguyen to estimate the sensitivity of Fermilab's DUNE Near Detector site to detecting millicharged particles (MCPs) as well as heavy axion-like particles (ALPs). The majority of my work for this project focused on the MCP search. Regarding the MCP search, we utilized the setup of a proposed project named FerMINI \cite{Kelly:2018brz} to look for a MCP would be generated from charged pion scattering- a production channel that has been so far overlooked. We would use the DUNE Near Detector complex at Fermilab, with the additional installation of scintillator arrays and photomultiplier tubes (PMTs), to detect MCPs through soft ionizations. Fermilab's proton beam would pass through a graphite target, producing charged pions that secondarily scatter in the target to produce a pair from a virtual photon. The signature for detecting a MCP would be three soft ionizations through the scintillator arrays that are collinear with the beam line and target, detectable through the collection of photoelectrons by PMTs. Using the framework of chiral perturbation theory, we found a small region of parameter space, around GeV, where the charged pion production channel dominates over previously-considered production mechanisms. Regarding the ALP search, we proposed a search strategy that would use the DUNE Near Detector complex and charged pions to detect heavy axion-like particles (ALPs) with low-energy couplings to gluons. Again, using the framework of chiral perturbation theory, we demonstrated regimes of parameter space where the charged pion production channel dominates over previously-considered production mechanisms for ALPs, thereby improving the sensitivity of DUNE to these new particles compared to previous studies
Dynamics of premixed flames in closed vessels
Get PDFSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Gautham Krishnan, accepted the attached license on 2025-05-13 at 14:45.The student, Gautham Krishnan, submitted this Dissertation for approval on 2025-05-13 at 15:01.This Dissertation was approved for publication on 2025-05-19 at 13:36.DSpace SAF Submission Ingestion Package generated from Vireo submission #22298 on 2025-10-20 at 16:57:03Premixed flame propagation within closed vessels is ubiquitous within diverse engineering applications such as IC engines, combustors and bomb calorimeters, as well as in fundamental experimental characterizations of combustible mixtures using constant-volume spherical bombs. Unlike freely propagating flames that propagate under nearly isobaric conditions, combustion in a closed vessel results in continuous increases in pressure, burning rate and flame temperature, and a progressive decrease in flame thickness. To model these flames crucial to the engineering design of combustion devices, their safety considerations, as well as fundamental physical understanding, a hydrodynamic theory of premixed flame propagation within closed vessels is developed assuming the flame is much thinner than all other fluid dynamic lengths. In this limit, the flame is confined to a surface separating the unburned mixture from burned combustion products, and propagates at a speed determined from the analysis of its internal structure. Through this asymptotic analysis, the flame speed is found to depend on the voluminal stretch rate, which measures the deformation of a volume element of the flame zone, and on the rate of pressure rise. Both effects are modulated by pressure-dependent Markstein numbers—parameters that lump the effects of heat release and mixture properties while capturing the effects of temperature-dependent transport and stoichiometry. The model, deduced from physical first principles, reduces the full combustion problem to a free-boundary hydrodynamic problem and applies to flames of arbitrary shape propagating in general flows, laminar or turbulent, within vessels of arbitrary configuration. It is employed to describe the canonical configurations of smooth planar, spherical and cylindrical flames in closed rectangular, spherical and cylindrical vessels respectively. The large gas expansion resulting from exothermic combustion reactions at the flame front is known to induce flame corrugation via the well-known Darrieus-Landau (DL) instability. Moreover, the propensity of premixed flames to become corrugated under the influence of intrinsic instabilities is strengthened under the pressure rise that manifests in closed vessel combustion. The hydrodynamic theory is particularly well-suited for investigating the flame wrinkling and acceleration driven by this hydrodynamic instability in mixtures of positive Markstein number. To study the dynamics of such multi-dimensional wrinkled flames, we resort to a numerical approach. For the numerical solution of the free-boundary hydrodynamic problem, a hybrid embedded-manifold/Navier-Stokes methodology has been developed and implemented within a variable-density zero-Mach number Navier-Stokes solver. An immersed boundary method is utilized to implement boundary conditions at the walls of vessels of arbitrary shape. The methodology is adept at developing a comprehensive understanding of the effects of instabilities and low-intensity turbulence on the propagation of premixed flames in closed vessels, being able to handle multiply-folded and disjoint surfaces, representing the highly corrugated flames that result under such conditions. This provides a tremendous opportunity to simulate and obtain fundamental understanding of the effects of turbulence and combustion instabilities on the burning rate, self-acceleration and fractal nature of the flame, which due to the sheer numerical costs is impractical to study by Direct Numerical Simulations (DNS) particularly when examining the large parametric space of interest and within large physically relevant domain sizes. The numerical approach is validated against exact analytical solutions of planar and cylindrical flames, and is shown to describe highly corrugated flame conformations resulting from intrinsic combustion instabilities, in rectangular and circular domains. As a first application of the model, the onset and subsequent nonlinear evolution of the DL instability is systematically investigated in the canonical configuration of a nominally planar flame within a rectangular channel closed at both ends. The onset of instability in the channel is shown to be delayed when compared to freely propagating flames under similar conditions due to the confinement of the burned gas flow between the flame and channel wall. The unstable flame is first observed to develop a cusp-like shape with an intrusion pointing toward the burned gas, which is a characteristic signature of the DL instability. However, unlike the steadily propagating cusp-like structure formed in open space, compression and pressure rise lead to a continually evolving morphology characterized by a repetitive cell splitting and merging behavior which affects the flame surface area and, consequently, the overall flame propagation rate. The tendency towards steady cusp-like propagation is observed only in extremely long channels. The dynamic change in Markstein number associated with the pressure rise in the vessel leads to corrugated flames even for conditions where freely propagating planar flames remain stable. To further analyze the effects of vessel geometry and pressure rise on instability development, outwardly expanding cylindrical flames within closed cylindrical vessels are investigated. This second configuration serves to highlight the distinct physical mechanisms relevant to experiments within spherical/cylindrical bombs used to measure some of the most important and fundamental properties that characterize a combustible mixture—the laminar flame speed and Markstein number. As uncovered in prior studies of freely expanding cylindrical flames, disturbances on the flame surface are found to initially be damped until the flame grows to a critical size where flame perturbations commence growth, marking the onset of the DL instability. This critical size is shown to be sensitive to the wavenumbers of flame surface perturbation modes, with numerical predictions of the most unstable mode consistent with theory. The subsequent nonlinear evolution of the instability exhibits cell-splitting and merging behavior with associated intermittent flame acceleration, highlighted first for a freely expanding flame and then contrasted with flame morphologies within vessels of various sizes. With a reduction in vessel size, these bouts of acceleration become dominated by an overall flame deceleration resulting from its propagation into an unburned mixture that becomes progressively denser with pressure rise. Consistent with experimental observations of the self-acceleration of such flames and the hypothesis of its dependence on a self-similar flame morphology, fractal dimensions are extracted from simulations highlighting greater flame corrugation and acceleration for smaller Markstein numbers
Fundamental physics in extreme-gravity environments
Get PDFSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Yiqi Xie, accepted the attached license on 2025-07-07 at 13:20.The student, Yiqi Xie, submitted this Dissertation for approval on 2025-07-11 at 15:50.This Dissertation was approved for publication on 2025-07-16 at 08:52.DSpace SAF Submission Ingestion Package generated from Vireo submission #22430 on 2025-10-20 at 16:57:30Extreme gravity sourced by compact objects and their coalescences is a great avenue for testing Einstein’s general relativity and is deeply interconnected with fundamental physics. In this dissertation, we discuss three topics on the interplay between extreme gravity and fundamental physics driven by recent observational advancements. The first topic concerns making predictions about black holes in modified gravity. We prove that the spacetimes of isolated black holes in a broad class of modified gravity theories must be circular, justifying the long-existing use of a circular ansatz to simplify black hole solutions in these theories. We then analytically calculate the observables of the Blandford–Znajek process around a supermassive black hole in quadratic gravity. The calculation reveals a degeneracy between the black hole’s spin and the quadratic coupling, which hinders such an effect from constraining quadratic gravity unless the black hole is fast-spinning. The second topic concerns deciphering fundamental physics implications in gravitational-wave data from observations of compact binary coalescences. We search over the current gravitational-wave transient catalog for activated dipolar emission from massive scalar fields nonminimally coupled to gravity. Our Bayesian analysis suggests no evidence for these fields and places the most stringent upper-bound constraints on their coupling strengths. We then generalize the above search and combine it with the LIGO-Virgo-KAGRA parametrized inspiral tests of general relativity. This is achieved by extending the parametrized post-Einsteinian framework behind these tests using neural networks. We find that the resulting new framework leads to more theory-agnostic and more efficient tests of general relativity using gravitational waves. The third topic concerns improving gravitational-wave measurements of compact binary coalescences using domain knowledge from nuclear astrophysics. We show that modeling binary neutron star signals with binary Love relations breaks the distance-inclination degeneracy and improves the measurement of the neutron star masses. We forecast the decrease in the measurement error in the era of third-generation detectors, and we relax the assumptions behind our approach to prove the robustness of our forecasts
Patronus: multi-modal sensing, analytics, and localization assistance for heterogeneous working environments
No full textSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Beitong Tian, accepted the attached license on 2025-07-08 at 13:45.The student, Beitong Tian, submitted this Dissertation for approval on 2025-07-08 at 14:09.This Dissertation was approved for publication on 2025-07-08 at 15:53.DSpace SAF Submission Ingestion Package generated from Vireo submission #22441 on 2025-10-20 at 16:57:30Today’s “Jarvis-like” AI assistants excel at generic, consumer-oriented tasks, yet they remain ill-suited for heterogeneous working environments—dynamic laboratories and industrial facilities where hands-on professionals must juggle safety-critical processes, rapidly changing context, and a deluge of multimodal data. This thesis argues that effective assistance in these settings hinges on the tight co-design of three pillars: (i) a low-cost, scalable, and evolvable sensing infrastructure, (ii) a trustworthy real-time analytics pipeline, and (iii) an accurate, practical localization layer that enables context-aware humandata interaction. In this thesis, we introduce Patronus, a modular framework composed of five interoperable systems that collectively satisfy these requirements. SENSELET++ deploys a plug-and-play sensor network and anomaly analytics for scalable environmental monitoring. MachineStethoscope enables on-device, unsupervised health monitoring for legacy rotating machinery. WeldMon fuses heterogeneous signals and introduces synthetic fault augmentation to improve failure prediction in ultrasonic welding. GaugeTracker digitizes analog gauges entirely on low-cost IoT hardware, leveraging multiple vision and vision language models for robust transcription. Finally, AnyLoc provides energy-efficient visual localization that operates under low-resolution and low-light conditions in cluttered indoor scenes. Together, these systems power MAINTGlasses, a hands-free smart-glasses interface that delivers spatially relevant insights to professionals in real time. Deployments across cleanrooms, nanofabrication labs, and server rooms demonstrate that Patronus fosters safer, faster, and more efficient workflows. By unifying sensing, analytics, and localization, this work charts a practical path toward intelligent environments that actively understand and support complex human work
Using environmental nonprofits to refine rules of interest group behavior
Get PDFSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Soren Warland, accepted the attached license on 2025-07-09 at 18:49.The student, Soren Warland, submitted this Dissertation for approval on 2025-07-09 at 18:53.This Dissertation was approved for publication on 2025-07-10 at 13:35.DSpace SAF Submission Ingestion Package generated from Vireo submission #22476 on 2025-10-20 at 16:57:39Interest groups often exert their influence by working with one or more organizations in an alliance. Interest group literature focuses disproportionately on lobbying organizations, but studying the behavior of nonprofits helps refine or refute some generalizations about interest group behavior. Furthermore, many studies neglect the factor of identity in helping or hindering alliances. This dissertation studies coalitional behavior through interviews of nonprofit leaders, examination of social media data, and analysis of archival documents. These analyses demonstrate that it is important to consider the differences between nonprofit and for-profit organizations when studying coalitions, and that identity is a crucial factor in determining what groups an organization partners with
Learning controllable visual representations: advancing spatial and 3D primitive guidance for image synthesis
No full textSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Vaibhav Vavilala, accepted the attached license on 2025-07-16 at 12:03.The student, Vaibhav Vavilala, submitted this Dissertation for approval on 2025-07-16 at 12:42.This Dissertation was approved for publication on 2025-07-16 at 14:05.DSpace SAF Submission Ingestion Package generated from Vireo submission #22599 on 2025-10-20 at 16:58:36Primitives have been a longstanding interest in computer vision because they can simplify reasoning about images and 3D data. Our work dramatically advances this area, providing an efficient method to obtain 3D primitive representations from any RGB image. In the chapter Convex Decomposition of Indoor Scenes, we show how we can fit 3D primitives to complex cluttered indoor scenes, focusing on the benchmark NYUv2 dataset. We depart from classic primitive fitting that decomposes 3D meshes and show how a single depth map is sufficient during training and inference. Further, we demonstrate that a two-stage method at test-time is effective: regression - running a neural net to obtain initial primitive predictions, followed by optimization - refining the primitives with respect to the original training losses. From there, in Improved Convex Decomposition with Ensembling and Boolean Primitives we scale the dataset to over a million images, demonstrating which assumptions matter for in-the-wild scenes. We then show how to fit CSG (Constructive Solid Geometry) representations, enriching the shapes we can encode. The primitive fitting problem is unique in that we do not know the optimal number of primitives for a given test image. Thus, we show how ensembling at test-time can help us choose. Finally, in Generative Blocks World, we establish why primitives are useful. While text-to-image models abound, users wish for precise 3D control over their outputs in a user-friendly way. We demonstrate that our primitives are excellent for this multimodal task, combining the latest image diffusion models with our 3D primitive representations. Our method allows us to move the camera or individual objects in a 3D-aware way, using our primitives as an intermediate abstraction
Influencing language: A study of Mandarin and Korean teacher-influencers and language ideology in the social media space
No full textSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Elizabeth King, accepted the attached license on 2025-07-07 at 00:08.The student, Elizabeth King, submitted this Dissertation for approval on 2025-07-07 at 00:19.This Dissertation was approved for publication on 2025-07-08 at 16:53.DSpace SAF Submission Ingestion Package generated from Vireo submission #22419 on 2025-10-20 at 20:14:58This dissertation investigates social media teacher-influencers and the discursive practices through which they influence the language ideologies of their audiences. Language teaching on algorithm-driven social media applications is a popular niche for content creators who wish to seek out an audience beyond the traditional classroom. But these content creators, who I call “teacher-influencers,” are not only seeking audience for what could be deemed as merely edutainment. Instead, teacher-influencers both replicate and challenge what Bourdieu (1974) called the “academic market” as they carve out niches for their own teaching style and make appeals to potential learners based on the perceived capital held by the languages they teach. This academic market of social media affords teacher-influencers the opportunity to challenge traditional hierarchies reproduced in formal educational institutions as they instead position themselves as more effective, authentic, or relevant teachers of a target language, a positioning afforded to them by the dynamics of the social media space. This creative, teacher-influencer-centered marketplace thus becomes a site for negotiation of language ideologies, as teacher-influencers capitalize on perceptions of linguistic capital in pursuit of an attentive audience. Within influencer-driven learning networks, dominant ideologies emerge across the social media content created by these teacher influencers. Using discourse-centered social media ethnography, I first define the teacher-influencer and the ways their online teaching blurs the boundaries between formal, informal, and nonformal language teaching (Dressman, 2020). I then examine two groups of teacher influencers: Taiwanese Mandarin teachers and Korean teachers. I argue that the Taiwanese-Mandarin teacher-influencers create an alternative academic market where Taiwanese Mandarin is consistently positioned as a legitimate and distinct variety of Mandarin Chinese. I argue that the Korean language teacher-influencers negotiate the role of Hallyu, or the Korean Wave, as the main factor motivating Korean language learning, with some teacher-influencers orienting toward a more “serious” type of language study as a more legitimate goal. This research argues that teacher-influencers demonstrate the potential of online language learning to challenge traditional pedagogies by reshaping the language learning “classroom” into a complex, multifaceted, asynchronous network of affiliations where the intersection of language and culture is realized
Analysis of stimuli responsive molecules: exploring pH-sensitive acid generators and redox-active molecules for electrochemical CO2 capture
Get PDFSubmission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo termsThe student, Joel Roberts, accepted the attached license on 2025-07-15 at 22:35.The student, Joel Roberts, submitted this Dissertation for approval on 2025-07-15 at 23:00.This Dissertation was approved for publication on 2025-07-18 at 16:37.DSpace SAF Submission Ingestion Package generated from Vireo submission #22593 on 2025-10-20 at 20:15:19Stimuli responsive molecules have come into focus as a mode of analyzing biological and environmental mechanisms of interests. Methods of analysis range from the chemiluminescent Schaap’s dioxetane to self-immolating polymers. Of particular interest for targeting cancer drug delivery and aiming at carbon dioxide capture are 4-chloromethylphenyl acetals and flavins, respectively. Herein, we have explored the applications of acid and voltage sensitive small molecules that can be used with the aim of challenging selective cancer drug delivery and electrochemical mediated carbon capture. We were able to use analytical methods such as NMR, LC-MS and HPLC along with generating pH-time curves to elucidate the mechanism of the hydrolysis of acid-sensitive 4-chloromethylphenyl acetals under extracellular tumor pH. We also analyzed how well an anthraquinone and flavin derivative can capture carbon dioxide under an applied voltage. We characterized these voltage sensitive molecules using cyclic voltammetry and ATR-SIERAS to explore how they capture carbon dioxide in real time. These molecular platforms may be useful in developing cancer selective drug delivery vehicles and more effective carbon capturing technologies