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Every introductory thermodynamics text [15] [16] presents the fact that on such a plane the area under any curve is the heat transfer to the substance per mole, positive going from left to right and negative from right to left; moreover, in a cyclic process the net heat transfer to the substance is the area enclosed by the cycle's closed curve.
In more detail (in the ZND model) in the frame of the leading shock of the detonation wave, gases enter at supersonic velocity and are compressed through the shock to a high-density, subsonic flow. This sudden change in pressure initiates the chemical (or sometimes, as in steam explosions , physical) energy release.
Cyclic acetals are very much more stable against acid hydrolysis than acyclic acetals. Consequently acyclic acetals are used practically only when a very mild cleavage is required or when two different protected carbonyl groups must be differentiated in their liberation.
For a given gas, the voltage is a function only of the product of the pressure and gap length. [2] [3] The curve he found of voltage versus the pressure-gap length product (right) is called Paschen's curve. He found an equation that fit these curves, which is now called Paschen's law. [3]
For air with a heat capacity ratio =, then =; other gases have in the range 1.09 (e.g. butane) to 1.67 (monatomic gases), so the critical pressure ratio varies in the range < / <, which means that, depending on the gas, choked flow usually occurs when the downstream static pressure drops to below 0.487 to 0.587 times the absolute pressure in ...
With this variant of PSA developed for use in laboratory nitrogen generators, nitrogen gas is produced into two steps: in the first step, the compressed air is forced to pass through a carbon molecular sieve to produce nitrogen at a purity of approximately 98%; in the second step this nitrogen is forced to pass into a second carbon molecular ...
The Strouhal number depends on the Reynolds number, [5] but a value of 0.22 is commonly used. [6] As the unit is dimensionless, any set of units can be used for the variables. Over four orders of magnitude in Reynolds number, from 10 2 to 10 5, the Strouhal number varies only between 0.18 and 0.22. [5]
Typically in thermodynamics, the set of processes forms a cycle, so that upon completion of the cycle there has been no net change in state of the system; i.e. the device returns to the starting pressure and volume. [citation needed] The figure shows the features of an idealized PV diagram. It shows a series of numbered states (1 through 4).