Rheology of bidisperse non-Brownian suspensions.

We study the rheology of bidisperse non-Brownian suspensions using particle-based simulation, mapping the viscosity as a function of the size ratio of the species, their relative abundance, and the overall solid content. The variation of the viscosity with applied stress exhibits shear-thickening phenomenology irrespective of composition, though the stress-dependent limiting solids fraction governing the viscosity and its divergence point are nonmonotonic in the mixing ratio. Contact force data demonstrate an asymmetric exchange in the dominant stress contribution from large-large to small-small particle contacts as the mixing ratio of the species evolves.

Women in dental education and their desire to lead: A follow-up.

The aim of this study was to provide a follow-up to the 2015 national survey of women in dental education to re-examine factors and perceived barriers to pursuing administrative and leadership roles. At the beginning of 2023, a survey was administered to full-time women faculty in predoctoral dental programs in the United States. The survey instrument employed a structured format along with open-ended questions to capture qualitative data.

Shear flow of non-Brownian rod-sphere mixtures near jamming.

We use the discrete element method, taking particle contact and hydrodynamic lubrication into account, to unveil the shear rheology of suspensions of frictionless non-Brownian rods in the dense packing fraction regime. We find that, analogously to the random close packing volume fraction, the shear-driven jamming point of this system varies in a nonmonotonic fashion as a function of the rod aspect ratio. The latter strongly influences how the addition of rodlike particles affects the rheological response of a suspension of frictionless non-Brownian spheres to an external shear flow.

Scaling Description of Frictionless Dense Suspensions under Inhomogeneous Flow.

Predicting the rheology of dense suspensions under inhomogeneous flow is crucial in many industrial and geophysical applications, yet the conventional "μ(J)" framework is limited to homogeneous conditions in which the shear rate and solids fraction are spatially invariant. To address this shortcoming, we use particle-based simulations of frictionless dense suspensions to derive new constitutive laws that unify the rheological response under both homogeneous and inhomogeneous conditions. By defining a new dimensionless number associated with particle velocity fluctuations and combining it with the viscous number, the macroscopic friction, and the solids fraction, we obtain scaling relations that collapse data from homogeneous and inhomogeneous simulations.

Approach to Solitary Thyroid Nodules in Adults.

Thyroid nodules are exceedingly common in the general population and their increasing incidence appears to be secondary to incidental finding on imaging. Nonetheless, due to the potential for malignancy and thyroid dysfunction, most thyroid nodules require further investigation. Although there are no current guidelines for thyroid cancer screening in asymptomatic patients, a thorough history and physical which focuses on risk factors can serve as a good starting point during the evaluation of a thyroid nodule.