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Benchmark Dose Modeling With Covariates For Nanomaterials, Sarah E. Davidson Jan 2016

Benchmark Dose Modeling With Covariates For Nanomaterials, Sarah E. Davidson

Mathematics

In the last decade, the use of engineered nanomaterials (ENMs) such as titanium dioxide (TiO2), carbon nanotubes (CNTs), carbon nanofibers (CNFs), as well as a variety of other materials have become increasingly popular in commerce because of their many beneficial properties (e.g. ability to manufacture products that are lighter, stronger, and/or more compact). However, according to the National Institute of Occupational Safety and Health, with the development of new nanotechnology it is prudent to ensure the health and safety of workers who are producing or using these materials at the forefront. For many ENMs, occupational exposure limits (OELs) are not …


Vorticity Dynamics And Sound Generation In Two-Dimensional Fluid Flow, Raymond J. Nagem, Guido Sandri, David Uminsky Jan 2007

Vorticity Dynamics And Sound Generation In Two-Dimensional Fluid Flow, Raymond J. Nagem, Guido Sandri, David Uminsky

Mathematics

An approximate solution to the two-dimensional incompressible fluid equations is constructed by expanding the vorticity field in a series of derivatives of a Gaussian vortex. The expansion is used to analyze the motion of a corotating Gaussian vortex pair, and the spatial rotation frequency of the vortex pair is derived directly from the fluid vorticity equation. The resulting rotation frequency includes the effects of finite vortex core size and viscosity and reduces, in the appropriate limit, to the rotation frequency of the Kirchhoff point vortex theory. The expansion is then used in the low Mach number Lighthill equation to derive …