Our understanding of animal flight benefits greatly from specialized wind tunnels designed for flying animals. Existing facilities can simulate laminar flow during straight, ascending and descending flight, as well as at different altitudes. However, the atmosphere in which animals fly is even more complex. Flow can be laminar and quiet at high altitudes but highly turbulent near the ground, an...

The development of non-equilibrium group IV nanoscale alloys is critical to achieving new functionalities, such as the formation of a direct bandgap in a conventional indirect bandgap elemental semiconductor. Here, we describe the fabrication of uniform diameter, direct bandgap Ge(1-x)Sn(x) alloy nanowires, with a Sn incorporation up to 9.2 at.%, far in excess of the equilibrium solubility of S...

Heteroepitaxial growth of Ge nanowires was carried out on Si(111) substrates by MBE. Au seeds were used as precursor for the VLS growth of the nanowires. Even if the Au droplets do not act as catalyst for the dissociation of gas, they are local preferential areas where the energetic barrier of Ge nucleation is lowered compare to the remaining non activated surface. Two sets of Au seeds were use...

‎In a recent paper C‎. ‎Miguel proved that the diameter of the commuting graph of the matrix ring $mathrm{M}_n(mathbb{R})$ is equal to $4$ if either $n=3$ or $ngeq5$‎. ‎But the case $n=4$ remained open‎, ‎since the diameter could be $4$ or $5$‎. ‎In this work we close the problem showing that also in this case the diameter is $4$.

We present electronic transport measurements in individual Au-catalyst/Ge-nanowire interfaces demonstrating the presence of a Schottky barrier. Surprisingly, the small-bias conductance density increases with decreasing diameter. Theoretical calculations suggest that this effect arises because electron-hole recombination in the depletion region is the dominant charge transport mechanism, with a ...

In this paper, the influence of aggregate size and volume fraction on shrinkage induced micro-cracking and permeability of concrete and mortar was investigated. Nonlinear finite element analyses of model concrete and mortar specimens were performed. The aggregate diameter was varied between 2 and 16 mm. Furthermore, a range of volume fractions between 0.1 and 0.5 was studied. The nonlinear anal...

Applicable Pollutants: Particulate Matter (PM), including particulate matter less than or equal to 10 micrometers (:m) in aerodynamic diameter (PM10), particulate matter less than or equal to 2.5 :m in aerodynamic diameter (PM2.5), and hazardous air pollutants (HAPs) that are in particulate form, such as most metals (mercury is the notable exception, as a significant portion of emissions are in...

3. Applicable Pollutants: Particulate Matter (PM), including particulate matter less than or equal to 10 micrometers (μm) in aerodynamic diameter (PM10), particulate matter less than or equal to 2.5 μm in aerodynamic diameter (PM2.5), and hazardous air pollutants (HAPs) that are in particulate form, such as most metals (except mercury is the notable exception, as a significant portion of emissi...

3. Applicable Pollutants: Submicron Particulate Matter (PM) greater than or equal to 0.3 micrometer (μm) in aerodynamic diameter, and PM greater than or equal to 0.12 μm in aerodynamic diameter that is chemically, biologically, or radioactively toxic; hazardous air pollutants (HAPs) that are in particulate form, such as most metals (mercury is the notable exception, as a significant portion of ...