Thermal conductivity electrons. In this case the mean velocity is the Fermi velocity which is temperature independent. The mean free path is determined by the impurities and the crystal imperfections which are temperature independent as well. So the only temperature-dependent quantity is the heat capacity "c", which, in this case, is proportional to "T". So with "k" a constant. For pure metals such as copper, silver, etc. "l" is large, so the thermal conductivity is high. At higher temperatures the mean free path is limited by the phonons, so the thermal conductivity tends to decrease with temperature. In alloys the density of
Composite reflectivity Composite reflectivity The composite reflectivity is the maximum dBZ reflectivity from any of the reflectivity angles of the NEXRAD weather radar. The reflectivity on individual PPI angles show the precipitation intensity at that specific angle above the horizon. Some of these angles are .5, 1.45, 2.4, and 3.35 degrees with the Doppler radar having up to 14 angles when it's in Severe Mode. In the Composite, the highest intensities amongst those available in the different angles above each point of the image will be displayed. In the Canadian weather radar network, this is called MAXR, for "Maximum reflectivity" in the