Binary Black Hole Merger

Understanding sound radiation from the human voice has broad applications in room acoustical design, telecommunications, physical modeling of the singing voice, and virtual acoustics. Head simulators and head and torso simulators can provide simplified approximations to voice directivity, which motivate their use in room acoustical and other related measurements. Nonetheless, recent works have shown that scattering and diffraction due to the torso alter speech radiation patterns compared to those produced from an isolated head alone. Despite the improvements that including a torso provides, most commercial voice simulators neglect the effects of human legs. To better understand the impact of leg scattering and diffraction on voice directivity, this work presents measurements of a manikin with a head, torso, and legs. Comparing the results with those measured from human talkers shows that scattering and diffraction from human legs can impact voice radiation patterns, particularly above 1 kHz. The results also highlight the importance of high spatial sampling resolution when performing directivity measurements, as these scattering effects are easily spatially aliased in lower resolution sampling schemes.

Reports of audible sonic booms along the south-central California coast during SpaceX Falcon 9 launch ascents prompted measurements in Ventura County during summer 2024. A total of 132 measurements were made over six launches, with 16–25 measurements per launch. The maximum overpressure measured was 1.90 psf (133 dB), but most measured booms had an overpressure below 0.5 psf and durations of several seconds. Two launches had appreciably lower overpressures and smaller terrestrial footprint, indicating that both meteorology and launch azimuth are important factors in terrestrial boom audibility. Agreement between this dataset and environmental assessment predictions was marginal.

The quantum dimer magnet, with antiferromagnetic intradimer and interdimer Heisenberg exchange between spin-1/2 moments, is known to host an $$(\left|\uparrow \downarrow \right\rangle -\left|\downarrow \uparrow \right\rangle )/\sqrt{2}$$singlet ground state when the intradimer exchange is dominant. Rare-earth-based quantum dimer systems with strong spin-orbit coupling offer the opportunity for tuning their magnetic properties by using magnetic anisotropy as a control knob. Here, we present bulk characterization and neutron scattering measurements of the quantum dimer magnet Yb2Be2SiO7. We find that the Yb3+ ions can be described by an effective spin-1/2 model at low temperatures and the system does not show signs of magnetic order down to 50 mK. The magnetization, heat capacity, and neutron spectroscopy data can be well-described by an isolated dimer model with highly anisotropic exchange that stabilizes a singlet ground state with a wavefunction $$(\left|\uparrow \uparrow \right\rangle -\left|\downarrow \downarrow \right\rangle )/\sqrt{2}$$or $$(\left|\uparrow \uparrow \right\rangle+\left|\downarrow \downarrow \right\rangle )/\sqrt{2}$$. Our results show that strong spin-orbit coupling can induce unusual entangled states of matter in quantum dimer magnets.

This paper presents ambient | global, an ambient soundscape model developed to predict global ambient sound levels from all anthropogenic, biological, and geophysical sources. The soundscape model adopts a geospatial approach by modeling the ambient sound level as a function of geospatial features at a location. The soundscape model consists of an ensemble of four machine learning regression models fitted at acoustic measurement sites where both the geospatial features and ambient sound levels are known. The fitted model is then applied to predict ambient sound levels at any location where the geospatial features are known. The results quantify the spatial, temporal, and spectral patterns of ambient sound levels across the world under various scenarios. This paper presents maps of the existing ambient sound levels across the world in terms of the daytime overall A-weighted L50, or median sound level, and partitions the existing sound levels into their natural and anthropogenic constituents. Ultimately, the soundscape model will enable research into the impacts of humans and nature on the ambient soundscape and the impacts of ambient sound levels on humans and nature across the world.

This study describes a carrier having submicron, uniform and non-aggregated poly lactic acid (PLA) spheres loaded with the anticancer drug 5-fluorouracil (5FU) and with 9 nm superparamagnetic iron oxide nanoparticles (SPIONs) for magnetically guided drug delivery and local controlled release. Using a water/organic/water (w/o/w) doubleemulsion process, we produced uniformly spherical microparticles smaller than 2 µm in diameter with well-dispersed SPIONs that retained superparamagnetic behavior after encapsulation. 5FU loading efficiency was determined to be 94%. Biological activity and chemical integrity was confirmed for the 5FU released from the product. Drug release kinetics showed faster release within the first day followed by sustained, slower release over 63 days with a cumulative release reaching 70% of loaded drug. Drug release was faster at 37°C compared to 21°C. PBS at pH 7.4 and 5.4 promoted faster release than did distilled water at pH 7.0. Release was prolonged from these PLA systems compared to other systems employing PLGA. This research introduces a rigorously optimized microcarrier system distinguished by sub-2-µm superparamagnetic PLA or PLGA microspheres of uniform morphology containing phase-dispersed SPIONs and exhibiting long-term controlled release, offering a transformative framework for magnetically directed drug delivery using high-gradient systems such as Halbach arrays.