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Abstract Ti₃C₂T_x(MXenes) are novel 2D nanomaterials with exceptional electrical conductivity. Their surfaces are covered with functional groups that may significantly affect material properties such as hydrophobicity, electrical conductivity, and oxidation resistance. The role of these terminations in high-temperature ceramic systems with regard to phase and microstructural evolution has not been investigated. In this study, Ti₃C₂T_x-SiOC 2D nanocomposites were fabricated with -F and -OH terminated MXene to evaluate the role of surface terminations in silane coupling and phase formation during the polymer-to-ceramic transformation. X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) identified self-etching mechanisms caused by F-terminated Ti₃C₂T_xand revealed that the F surface terminations were retained in the MXene structure until evolution at ~ 550 °C. Evolved F reacted with Si–H bonds in the transforming ceramic matrix, causing additional mass loss and volumetric deformation. LiOH alkalization was shown to suppress the self-etching phenomenon through the substitution of F groups with OH on the nanosheet surface. Furthermore, F terminations were determined to only engage in hydrogen bonding with silane molecules as opposed to covalent linkages with OH terminations, which accelerated silane removal and Ti₃C₂T_xdegradation. The study provides a fundamental understanding of the nature and behavior of MXene surface terminations in the context of high-temperature ceramic nanocomposite fabrication. 

Abstract In this study, montmorillonite (MMT) nanosheets are purified and exfoliated from a crude clay source and further twice‐functionalized with cetritrimethylammonium bromide and [3‐(2‐aminoethylamino)propyl]trimethoxysliane (AEAPTMS) to promote dispersion in the preceramic polymer. Phase profiles and compositions of MMT nanoflakes and MMT‐silicon oxycarbide (SiOC) are characterized with X‐ray diffraction, infrared spectroscopy, and thermogravimetric analysis. The microstructures are examined by scanning and transmission electron microscopy. MMT nanoflakes are randomly dispersed in the SiOC matrix with α‐quartz forming at the MMT‐SiOC interface. Pyrolysis to 1400 °C induced the formation of SiC nanowhiskers that are observed up to 20 µm in length and 200 nm in diameter. After selective etching of SiO₂domains with HF, pore sizes and specific surface areas of MMT‐SiOC are analyzed with nitrogen adsorption. The study provided a new fundamental understanding of MMT‐SiOC interactions at different pyrolysis temperatures and also led to composites with specific surface areas reaching 120 m² g⁻¹ up to 1200 °C pyrolysis, and between 340 and 772 m² g⁻¹at 1400 °C pyrolysis and pore size distributions between 2 and 5 nm. The methodology and results presented improve the understanding and viability of 2D nanomaterial‐reinforced ceramic composites and MMT as a precursor for nanostructured SiC. 

We present unreported mechanistic insight into how water vapor-assisted pyrolysis in the presence of MMT hinders SiO₂crystallization and carbon removal, demonstrating a reversal of water vapor-induced effects in the presence of MMT nanosheets. 

Abstract Fragmentation of marine snow affects the downward flux of organic matter, and other aggregate‐associated compounds such as oil. Using phytoplankton aggregates, we demonstrate that marine snow with oil, termed marine oil snow, had a higher resistance to fragmentation compared to marine snow without oil when exposed to turbulence ex situ. At moderate shear levels, typical of the ocean mixed layer, 17% of marine snow without oil broke, whereas 63% of marine snow fragmented at intermediate shear. In contrast, only 17% and 33% of marine oil snow fragmented at the intermediate and highest shear levels, respectively. Our results suggest that oil increases the cohesion and stability of aggregates making them less susceptible to breaking. This work contributes toward explaining the exceptional oil sedimentation event following the 2010 spill in Gulf of Mexico. It also enhances our understanding of the factors that determine the probability of sinking aggregates to fragment. 

Aim: Video review programs in hospitals play a crucial role in optimizing operating room workflows. In scenarios where split-seconds can change the outcome of a surgery, the potential of such programs to improve safety and efficiency is profound. However, leveraging this potential requires a systematic and automated analysis of human actions. Existing methods predominantly employ manual methods, which are labor-intensive, inconsistent, and difficult to scale. Here, we present an AI-based approach to systematically analyze the behavior and actions of individuals from operating rooms (OR) videos. Methods: We designed a novel framework for human mesh recovery from long-duration surgical videos by integrating existing human detection, tracking, and mesh recovery models. We then trained an action recognition model to predict surgical actions from the predicted temporal mesh sequences. To train and evaluate our approach, we annotated an in-house dataset of 864 five-second clips from simulated surgical videos with their corresponding actions. Results: Our best model achieves an F1 score and the area under the precision-recall curve (AUPRC) of 0.81 and 0.85, respectively, demonstrating that human mesh sequences can be successfully used to recover surgical actions from operating room videos. Model ablation studies suggest that action recognition performance is enhanced by composing human mesh representations with lower arm, pelvic, and cranial joints. Conclusion: Our work presents promising opportunities for OR video review programs to study human behavior in a systematic, scalable manner. 

This video shares the experiences of Dr. Matthew Rau as a Mechanical Engineer working collaboratively in the field of oceanography, with special highlights for opportunities for engineers interested in entering the field. 

We present results of a search for spin-independent dark matter-nucleus interactions in a $1{\mathrm{cm}}^2$by 1 mm thick (0.233 g) high-resolution silicon athermal phonon detector operated above ground. For interactions in the substrate, this detector achieves an rms baseline energy resolution of $361.5\left(4\right)\mathrm{m}\mathrm{eV}$(statistical error), the best for any athermal phonon detector to date. With an exposure of $0.233\mathrm{g}\times 12$hours, we place the most stringent constraints on dark matter masses between 44 and $87\mathrm{M}\mathrm{eV}/{\mathrm{c}}^2$, with the lowest unexplored cross section of $4\times {10}^{-32}{\mathrm{c}\mathrm{m}}^2$at $87\mathrm{M}\mathrm{eV}/{\mathrm{c}}^2$. We employ a conservative salting technique to reach the lowest dark matter mass ever probed via direct detection experiment. This constraint is enabled by two-channel rejection of low energy backgrounds that are coupled to individual sensors.