Propagation constant a conductor. The skin effect causes R along the conductor to be approximately dependent on frequency according to Losses in the dielectric depend on the loss tangent (tan "δ") of the material divided by the wavelength of the signal. Thus they are directly proportional to the frequency. The attenuation constant for a particular propagation mode in an optical fiber is the real part of the axial propagation constant. In electromagnetic theory, the phase constant, also called phase change constant, parameter or coefficient is the imaginary component of the propagation constant for a plane wave. It represents the change in phase
Bowditch Crests Bowditch Crests Bowditch Crests () is a line of precipitous cliffs surmounted by four summits on Bermel Peninsula in eastern Graham Land. The feature was photographed from the air by Lincoln Ellsworth in November 1935 and was mapped from these photos by W.L.G. Joerg. It was surveyed by the Falkland Islands Dependencies Survey in 1958, and named by the UK Antarctic Place-Names Committee for Nathaniel Bowditch, American astronomer and mathematician, author of "The New American Practical Navigator" (1801) which firmly set out the practical results of theories established at that date and has since gone through more than 56 editions.