Abstract: Understanding the fundamental interactions that influence molecular recognition is essential for advancing applications in drug design, sensing, and materials chemistry. This dissertation uses cryogenic ion vibrational spectroscopy (CIVS) to investigate noncovalent interactions in anion-receptor complexes by studying mass-selected gas-phase ions at cryogenic temperatures, eliminating complexities due to solvation effects. Studies of several calix[4]pyrrole receptors bound to either a halide or polyatomic anion reveal that the NH stretching features serve as sensitive probes of the hydrogen bonding strength between ion and receptor. Comparison with quantum chemical calculations yields insight into the binding motif of the guest ion and the structural changes of the receptor upon anion binding. This work also demonstrates CIVS as a powerful tool for unambiguous identification of biomarkers, successfully distinguishing constitutional isomers that would be indistinguishable by mass spectrometry alone.

Mid-Infrared (MIR) light can interact with molecules by selectively exciting molecular vibrational modes. In combination with photonic structures, MIR can target specific vibrational states of molecular to influence chemical reactions. In this talk, I will explain how photonic environments can modify molecular dynamics through strong light-matter coupling. This strong coupling leads to the molecular vibrational polaritons – a hybrid quasiparticle between light and matter. Using two-dimensional infrared (2D IR) spectroscopy, we have demonstrated that strong coupling to photonic environments can efficiently promote energy transfer within or between molecules, subsequently slowing down competing reaction pathways. We further explored the criteria to fulfill polariton-enabled energy transfer, by which we discovered and verified a new principle to enable intermolecular energy transfer through polaritons in disorder materials. Lastly, we employed a polariton propagation experiment to determine the number of active polariton states versus the inactive dark states. This research progress provide insights into a rational mechanism and designing photonic structures to modify chemical landscapes and influence reaction pathways.

Abstract: The scales of asteroid strength, from centimeters to tens of meters or more, can in principle be connected via the well-known Weibull theory (Weibull 1951) that explains in probabilistic terms why small samples of a rock are stronger than the whole. There are fewer weak flaws to be exploited in a smaller sample. This leads to a statistical understanding of size-dependent strength that has been implemented in fragmentation and damage models for planetary materials (Melosh et al., 1992; Benz and Asphaug 1994, 1995). The Weibull analysis enabled Cotto-Figueroa et al. (2016) to extrapolate laboratory measurements of meteorite strength of a carbonaceous (Allende, CV3) and an ordinary chondrite meteorite (Tamdakht, H5) to make predictions about the estimated strengths of objects of similar material, meters to tens of meters in size, i.e. large boulders on asteroids, and major atmospheric bolides. However, the application of size-dependent strength modeling to L-chondrite meteorites is perplexing. Recent studies of the Aba Panu (L3) and Viñales (L6) meteorites (Rabbi et al. 2021, 2023; Cotto-Figueroa et al. 2020, 2023), showed that they were more homogeneous than the meteorites previously studied, exhibiting therefore higher strengths at meter-scales, especially in the case of Aba Panu. The implication from the studies of the Aba Panu and Viñales meteorites is that meter-sized L-chondrite bolides should have greater airburst strengths than other ordinary chondrites. However, the reported "L fireballs" are quite weak. We are therefore conducting additional laboratory measurements of meteorite strength of two other L6 ordinary chondrites. Our goal is to better understand the scale-dependent mechanical properties of Near-Earth Objects and their components to help developing mitigation strategies from Potentially Hazardous Asteroids and for understanding properties of materials on asteroids during human and robotic exploration.

Edwards Vacuum will be providing a training on Ultra-high Vacuum (UHV) best practices, including best known methods on pump configuration, bake-out, etc.  The goal is to help align UHV best practices department wide to reduce experiment set-up time and re-work. This could also apply to those that do not use UHV today, but may like to take advantage of broadening their UHV knowledge for the future.

Please RSVP Edwards contact Nate Groneberg at ngroneberg@vacuumone.com by end of business on November 3rd.  Thank you and look forward to seeing everyone there!

The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.

Abstract: The most basic requirement of a scientific theory is that it make predictions. Is the Standard Model a scientific theory? As the well-tested, reigning theory of the elementary particles and fundamental forces, the Standard Model certainly claims to be able to predict the outcomes of a wide range of experiments. Yet from inelastic nuclear scattering, to neutron stars and superconductors, the universe is filled with systems whose behavior should be predicted by the Standard Model, but for which no such predictions are forthcoming!
For these systems, we do not need physics beyond the Standard Model. We need the computational power to determine what the predictions of the Standard Model already are. I will discuss the state-of-the-art in first-principles computations of strongly coupled quantum systems, and whether quantum computers—or anything—can salvage the notion of the Standard Model as our predictive theory of physics below the TeV scale.

Dr. Colum O'Leary, a Research Associate at the SLAC National Accelerator Laboratory, presents, “X-Ray and Electron Tomography: From Images to Volumes to Knowledge.”

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Abstract: This talk will explore how quantum radiation - known as Hawking radiation – emerges when a black hole forms in the gravitational collapse of a star. While it has long been known that black holes emit energy, its precise origin has been debated. Over the decades, some researchers proposed that this energy is released directly from the collapsing star, producing a sudden burst that may potentially disrupt the collapse. Using a somewhat idealized collapse model, we will see instead that the radiation emerges gradually from the region in the vicinity of the forming black hole (and not in a violent flash from the infalling matter).This resolves a long-standing question and corroborates the more conventional picture of Hawking radiation as a gradual, steady process that cannot interfere with black hole formation in gravitational collapse.

Quantum computing and sensing represent two distinct frontiers of quantum information science. Here, we harness quantum computing to solve a fundamental and practically important sensing problem: the detection of weak oscillating fields with unknown strength and frequency. We present a quantum computing enhanced sensing protocol, that we dub quantum search sensing, outperforming all existing approaches. Furthermore, we prove our approach is optimal by establishing the Grover-Heisenberg limit -- a fundamental lower bound on the minimum sensing time. The key idea is to robustly digitize the continuous, analog signal into a discrete operation, which is then integrated into a quantum algorithm. Our metrological gain originates from quantum computation, distinguishing our protocol from conventional sensing approaches. Indeed, we prove that broad classes of protocols based on quantum Fisher information, finite-lifetime quantum memory, or classical signal processing are strictly less powerful. We propose and analyze a proof-of-principle experiment using nitrogen-vacancy centers, where meaningful improvements are achievable using current technology. This work establishes quantum computation as a powerful new resource for advancing sensing capabilities.

The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.

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Abstract: Modeling gas-phase chemical kinetics relevant to combustion and atmospheric chemistry requires a complete description of elementary reactions involving ephemeral species such as hydroperoxyalkyl radicals, Q̇OOH, which undergo competing sets of unimolecular reactions and bimolecular reactions with O2. The balance of flux from the competition affects rates of chain-branching and inherently depends on temperature, pressure, and oxygen concentration. Accordingly, the influence of [O2] on species formed via reactions of O2 with carbon-centered radicals (Ṙ), and the subsequent fate of Q̇OOH and related products, is central to developing accurate chemical kinetics mechanisms. However, reactions consuming intermediates from Ṙ + O2 are often simplified to such a degree that mechanism truncation error (uncertainty derived from incomplete reaction networks) becomes significant and precludes high-fidelity simulations of chemical systems for sustainable transportation energy.

Intermediates produced from Ṙ + O2 reactions of hydrocarbons and biofuels include cyclic ethers and alkene isomers, which are shown to undergo two unique types of reactions that are neglected in current gas-phase combustion models: (1) non-Boltzmann reactions, wherein rovibrationally excited radicals produced during H-abstraction undergo prompt ring-opening prior to collisional stabilization, and (2) stereochemical-dependent reaction pathways originating in closed-shell cyclic ethers that follow from the preceding ring-closing transition state [Q̇OOH]≠ and from subsequent cyclic ether peroxy radicals, both of which can facilitate new reaction channels including chain-branching pathways.

To ameliorate predictive deficiencies, results from a coupled experimental-computational workflow are outlined wherein sub-mechanisms, informed by speciation experiments, are developed and utilized as input into AutoMech, an open-source code for quantum chemical mechanism development. AutoMech is employed to calculate ab initio thermochemical and rate coefficeints for all species and reaction pathways in an initial mechanism. Elementary reactions are translated by AutoMech from 2D descriptions into stereochemically-enumerated representations. Potential energy surfaces are calculated using explicitly-correlated coupled-cluster energies with dispersion-corrected double-hybrid density functional theory geometries and frequencies. Master equation theory is used to calculate pressure- and temperature-dependent rate coefficients and partition functions for each reaction and species including for non-Boltzmann reactions. Results discussed include ongoing projects on species derived from cyclopentyl radicals and alkyl-substituted cyclic ethers produced from pentyl radical isomers. 

Join us on Saturday, November 15, 2025, for an electrifying experience as CU Physics Professor Daniel Bolton uncovers the wonders of electric charges and magnets up close! Ever wondered how electrical attraction and repulsion function or what transpires inside an electric circuit? Curious about the inner workings of a power plant in generating electricity? 

Discover the answers to these questions and more at CU Wizards' captivating science demonstrations. For over 40 years, CU Wizards has been delighting audiences with free public family shows each month at CU Boulder. Everyone is welcome to attend these engaging and enlightening events. 

Don't miss out on this "electric" atmosphere of discovery! 

Abstract: The discovery of thousands of planets orbiting stars beyond the solar system has fundamentally shifted our view of Earth’s place in the Universe, has captivated the public imagination, and has transformed research priorities in astrophysics. We are now actively searching for atmospheres on temperate, terrestrial planets, and are developing the technical tools to find and characterize “Earth-2.0”. The goal of understanding the frequency and diversity of habitable (and inhabited) planets requires a `full system approach’ where we bring to bear multiple techniques for exoplanetary observation and a detailed understanding of the evolving stellar environments in which they live.

In this talk, I will present an overview of the multiple paths in our search for inhabited planets, from current efforts to find temperate planets with stable atmospheres around red dwarf stars to future detection of true Earth-Sun analogs with NASA’s upcoming Habitable Worlds Observatory (HWO). I will summarize recent progress and open questions in understanding the key stellar environmental variables that influence exoplanet atmospheres, focusing on observational and experimental work to characterize the high-energy photon and particle radiation that dominates atmospheric escape on rocky planets. I will conclude with a short overview of the upcoming HWO mission, current opportunities for the community to engage with the mission development, and the path to launch in the ~2040 timeframe.

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Abstract: A new zoo consisting of dozens of heavy subatomic particles that contain more than three quarks and antiquarks have been discovered beginning in 2003.  Although they must be described by the fundamental quantum field theory QCD, the pattern of these exotic heavy hadrons remained unexplained for more than 20 years.  I will present a simple proposal for the pattern based on the Born-Oppenheimer approximation for QCD.  There are simple calculations in lattice QCD that would corroborate the pattern.  The quantitative description of these exotic heavy hadrons requires the diabatic representation of the Born-Oppenheimer approximation, which has led to dramatic advances in atomic and molecular physics in recent decades.

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NASA science missions are often complex systems of systems, involving various stakeholders, including the United States’ Congress. To ensure a clear and concise communication of expectations, requirements, and constraints, NASA has adopted the Science Traceability Matrix (STM). STM provides a logical flow from the decadal survey to science goals and objectives, mission and instrument requirements, and data products. STM serves as a summary of what science will be achieved and how it will be achieved, with a clear definition of what mission success will look like. In this seminar, I will present the STM from the Parker Solar Probe (PSP), including requirements relating to the plasma instrument for which I am a co-investigator. I will describe how our team used the STM to map the mission’s top-level requirements to mission success criteria and helped to eliminate any single point of failure that could end the mission prematurely. I will then present my own research on magnetic switchbacks in the PSP magnetic and plasma observations and their role in solar wind acceleration and heating. I will conclude the seminar by discussing how my research on the temporal evolution of switchbacks in the solar wind led to a new STM, and helped to chart a multidisciplinary path to designing a ground-breaking science mission concept, titled Space Weather Investigation Frontier (SWIFT), with the potential to improve space weather forecasting lead times by up to 40%.

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The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.

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The Department of Biochemistry invites professors and scientists from other universities and institutes to present seminars at the University of Colorado Boulder throughout the academic year. These seminars provide an opportunity for faculty and students to learn about exciting current research.