This tutorial will explain the pumping system speed of sound concept (how to account for acoustic velocity changes due to pipe wall flexibility and liquid properties), the definition of quarter-wave, half-wave, and higher order acoustic mode shapes, the importance of each mode shape, and examples of how to estimate these mode shapes and frequencies. The use of basic acoustics to identify and re...

C. Pierpaoli1, S. Marenco1, G. Rohde1, D. K. Jones1, A. S. Barnett1 National Institutes of Health, Bethesda, Maryland, United States Synopsis: We analyze the contributions of cardiac-pulsation to the variability in estimates of diffusion tensor quantities in the human brain. We identify two contributions to variability arising from cardiac pulsation, namely (i) mis-registration of different str...

That some stars vary in brightness has been known from time immemorial. That this variation is the result of intrinsic changes in the star itself has been known for less than 100 years and the causes of those variations have been understood for less than 30 years. It is not a simple matter to distinguish the light variations resulting from eclipses by a companion from those caused by physical c...

Fourier decompositions are performed on the velocity curves of 11 classical Cepheids. The progression of curve shape with period is described in terms of combinations of the lower order Fourier coefficients. These quantities are shown to change with pulsation period in a manner similar to that already demonstrated for Cepheid light variations (Simon and Lee). We recommend further velocity obser...