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Phase equilibrium modeling and conventional thermobarometry are rooted in the assumption that chemical equilibrium is closely attained during metamorphism to determine the pressure-temperature (P-T) histories of metamorphic rocks. Alternatively, elastic thermobarometry, a complimentary method for P-T calculations, does not require chemical equilibrium constraints and is instead based on the elastic response of mineral inclusions and their host mineral upon exhumation. The most commonly used host-inclusion system is the quartz-in-garnet (QuiG) barometer, which has been experimentally evaluated and applied to many natural samples. Zircon-in-garnet (ZiG) is often cited as a host-inclusion pair that can be used for thermometry but has had far less application in natural case studies and has been observed to reset in atmospheric-pressure heating experiments (Campomenosi et al., 2023; Zhong et al., 2024). We performed piston-cylinder experiments entrapping synthetic zircons in almandine garnet at conditions of 700–900 °C and 2.0–3.0 GPa to experimentally evaluate the reliability of ZiG. We used Raman spectroscopy to measure the 356, 439, 975, and 1008 cm-1 phonon modes of synthesized zircon inclusions and calculated their peak shifts relative to a free synthetic zircon crystal. We subsequently calculated remnant inclusion strains, stresses, and pressures (Pinc) using the zircon phonon mode Grüneisen tensor approach (Angel et al., 2019) and elastic stiffness tensor (Cij) of zircon. ZiG host-inclusion pairs synthesized at pressures >2.0 GPa yield Pinc values within one standard deviation of expected values, corresponding to entrapment temperatures (Ttrap) within ~15 °C of experimental temperatures. experiments run at 2.0 GPa yield Pinc values that are ~0.08 GPa systematically higher than expected; this corresponds to Ttrap values that are ~60 °C higher than the experimental conditions. We hypothesize that systematic Pinc discrepancies in 2.0 GPa experiments potentially derived from slight errors in the zircon or garnet equations of state (EoS) and/or Cij tensors. Zircon, in particular, readily substitutes trace elements into its crystalline structure and can be altered by radiation damage, which, even in slight quantities, can greatly affect both the EoS and Cij relative to pristine zircon. Nonetheless, application of ZiG and QuiG elastic thermobarometry together is a potentially powerful tool for constraining the P-T conditions of metamorphic events independent of assumed chemical equilibrium. Angel, R.J., Murri, M., Mihailova, B., and Alvaro, M., 2019, Stress, strain, and Raman shifts: Zeitschrift für Kristallographie, v. 234, p. 129–140. Campomenosi, N., Angel, R.J., Alvaro, M., and Mihailova, B., 2023, Resetting of zircon inclusions in garnet: Implications for elastic thermobarometry: Geology, v. 51, p. 23–27, https://doi.org/10.1130/G50431.1. Zhong, X., Wallis, D., Kingsbery, P., and John, T., 2024, The effect of aqueous fluid on viscous relaxation of garnet and modification of inclusion pressures after entrapment: Earth and Planetary Science Letters, https://doi.org/10.1016/j.epsl.2024.118713. 

Students often experience difficulty in connecting knowledge from different college courses to solve complex problems such as ocean acidification, a pressing concern within the ongoing climate crisis. Here, we introduce a multidisciplinary activity in which students use their chemistry knowledge of change and stability in chemical systems through Le Chatelier’s principle and equilibrium of coupled reactions to explain the biological phenomenon of how changes in CO2 concentrations can impact shelled organisms and ecosystems more broadly in the ocean. In this activity, we build on prior literature and emphasize Three-Dimensional Learning (3DL) to support students in developing a deeper understanding of this complex problem. This Ocean Acidification activity asks students to explain (1) the relationship between CO2 concentration and ocean pH and (2) how and why changes in ocean pH could weaken shelled organisms. Among 136 students in a second-semester general chemistry course at a large institution, 93% were able to correctly predict the relationship between CO2 and pH (chemistry-biology connection). Additionally, 43% of the students were able to then further apply this knowledge correctly to explain an unfamiliar situation in which the decreased pH could lead to less available carbonate ion for the shells (biological phenomenon). This result highlights that while some students were able to correctly explain the biological phenomenon and make meaningful connections, others would require additional in-class scaffolding and student-instructor interaction to be able to integrate their knowledge to explain this unfamiliar complex biological phenomenon. Implications for teaching and future implementations are also discussed. 

Radio pulses generated by cosmic-ray air showers can be used to reconstruct key properties like the energy and depth of the electromagnetic component of cosmic-ray air showers. Radio detection threshold, influenced by natural and anthropogenic radio background, can be reduced through various techniques. In this work, we demonstrate that convolutional neural networks (CNNs) are an effective way to lower the threshold. We developed two CNNs: a classifier to distinguish radio signal waveforms from background noise and a denoiser to clean contaminated radio signals. Following the training and testing phases, we applied the networks to air-shower data triggered by scintillation detectors of the prototype station for the enhancement of IceTop, IceCube’s surface array at the South Pole. Over a four-month period, we identified 554 cosmic-ray events in coincidence with IceTop, approximately five times more compared to a reference method based on a cut on the signal-to-noise ratio. Comparisons with IceTop measurements of the same air showers confirmed that the CNNs reliably identified cosmic-ray radio pulses and outperformed the reference method. Additionally, we find that CNNs reduce the false-positive rate of air-shower candidates and effectively denoise radio waveforms, thereby improving the accuracy of the power and arrival time reconstruction of radio pulses. 

Vortices are one of the most promising mechanisms to locally concentrate millimeter dust grains and allow the formation of planetesimals through gravitational collapse. The outer disk around the binary system HD 142527 is known for its large horseshoe structure with azimuthal contrasts of ~3–5 in the gas surface density and of ~50 in the dust. Using 13 CO and C 18 O J = 3–2 transition lines, we detect kinematic deviations to the Keplerian rotation, which are consistent with the presence of a large vortex around the dust crescent, as well as a few spirals in the outer regions of the disk. Comparisons with a vortex model suggest velocity deviations up to 350 m s −1 after deprojection compared to the background Keplerian rotation, as well as an extension of ±40 au radially and ~200° azimuthally, yielding an azimuthal-to-radial aspect ratio of ~5. Another alternative for explaining the vortex-like signal implies artificial velocity deviations generated by beam smearing in association with variations of the gas velocity due to gas pressure gradients at the inner and outer edges of the circumbinary disk. The two scenarios are currently difficult to differentiate and, for this purpose, would probably require the use of multiple lines at a higher spatial resolution. The beam smearing effect, due to the finite spatial resolution of the observations and gradients in the line emission, should be common in observations of protoplanetary disks and may lead to misinterpretations of the gas velocity, in particular around ring-like structures. 

We present 50-fs, single-shot measurements of the x-ray thermal diffuse scattering (TDS) from copper foils that have been shocked via nanosecond laser ablation up to pressures above ∼135 GPa. We hence deduce the x-ray Debye–Waller factor, providing a temperature measurement. The targets were laser-shocked with the DiPOLE 100-X laser at the High Energy Density endstation of the European X-ray Free-Electron Laser. Single x-ray pulses, with a photon energy of 18 keV, were scattered from the samples and recorded on Varex detectors. Despite the targets being highly textured (as evinced by large variations in the elastic scattering) and with such texture changing upon compression, the absolute intensity of the azimuthally averaged inelastic TDS between the Bragg peaks is largely insensitive to these changes, and allowing for both Compton scattering and the low-level scattering from a sacrificial ablator layer provides a reliable measurement of T/ΘD2, where ΘD is the Debye temperature. We compare our results with the predictions of the SESAME 3336 and LEOS 290 equations of state for copper and find good agreement within experimental errors. We, thus, demonstrate that single-shot temperature measurements of dynamically compressed materials can be made via thermal diffuse scattering of XFEL radiation. 

The IceCube Upgrade is an extension of the existing IceCube Neutrino Observatory and will be deployed in the 2025–2026 austral summer. It will significantly improve the sensitivity of the detector to atmospheric neutrino oscillations. The existing 86-string IceCube array contains a dense in-fill known as DeepCore which is optimized to measure neutrinos with energies down to a few GeV. The IceCube Upgrade will consist of seven new densely instrumented strings placed within the DeepCore volume to further enhance the performance in the GeV energy range. The additional strings will feature new optical modules, each containing multiple photomultiplier tubes (PMTs), in contrast to the existing modules that each contain a single PMT. This will more than triple the number of PMT channels with respect to the current IceCube configuration, allowing for improved detection efficiency and reconstruction performance at GeV energies. We describe necessary updates to simulation, event selection, and reconstruction to accommodate the higher data rates observed by the upgraded detector and the addition of multi-PMT modules. We determine the expected sensitivity of the IceCube Upgrade to the atmospheric neutrino oscillation parameters ${\sin }^2{\theta }_{23}$and $\mathrm{\Delta }{m}_{32}^2$, the appearance of tau neutrinos and the neutrino mass ordering. The IceCube Upgrade will provide neutrino oscillation measurements that are of similar precision to those from accelerator experiments, while providing complementarity by probing higher energies and longer baselines, and with different sources of systematic uncertainties.