Variable density ( VD ) recording systems developed from Movietone gradually lost market share to variable area ( VA ) ones developed from Photophone from the 1940s onwards, a process that gathered pace as VA-related patents expired.
32.
The volume of the storm's total snowfall was later computed to be 12.91 mi?( 53.96 km?), an amount which would weigh ( depending on the variable density of snow ) between 5.4 and 27 billion tonnes.
33.
The alternative and ultimately the successor of variable density has been the " variable area " track, in which a clear, vertical waveform against black represents the sound, and the width of the waveform is equivalent to the amplitude.
34.
The idea of pressure-correction also exists in the case of variable density and high Mach numbers, although in this case there is a real physical meaning behind the coupling of dynamic pressure and velocity as arising from the " continuity equation"
35.
Accepting the challenge, Johann proposed the cycloid, the path of a point on a moving wheel, pointing out at the same time the relation this curve bears to the path described by a ray of light passing through strata of variable density.
36.
"' Variable density goggles "'were used by U . S . aerial gunners and anti-aircraft gunnerss in World War II . They were equipped with a turning dial on the front allowing the pilot to alter the tint of the lens enabling them to see tracer rounds and not be easily blinded.
37.
Similarly, a given mass " M " of gas with changing volume will have variable density & delta; = " M / V ", and the ideal gas law may be written " P = k T " & delta; so that an isobaric process traces a hyperbola in the quadrant of absolute temperature and gas density.
38.
Longhi was able to develop the Re . 2008 from the new Re . 2007 sketches he made after the war but pretended were from earlier days . The Re . 2008 models ( 1947 1948 ) were tested at Cornell Variable Density Wind Tunnel in 1949 . The definitive collapse of Caproni Group stopped all evolutions.
39.
This was followed by two papers communicated by Sir Bromhead to the Cambridge Philosophical Society : ( 1 ) "'On the Laws of the Equilibrium of Fluids analogous to the Electric Fluid "'( 12 Nov . 1832 ); ( 2 ) "'On the Determination of the Attractions of Ellipsoids of Variable Densities "'( 6 May 1833 ).
40.
Although sound films today use variable-area tracks, any modern motion picture theater ( excluding those that have transitioned to digital cinema ) can play a Movietone film without modification to the projector ( though if the projector has been fitted with red LED or laser photocells, the reproduction quality from a variable density track will be significantly impaired ).
