The bulk modulus, K or

The isothermal compressibility, written as or k, is the reciprocal of the bulk modulus. Beware of the 

This modulus determines the velocity of ultrasonic stress pulses through a solid. 

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Bulk Modulus and Bulk Compressibility. According to Cramer(Ref 5,P 1), one of the important constants of an isotropic elastic solid is the bulk modulus (K) or its reciprocal the bulk compressibility(B). The K is defined as the ratio of stress to strain when the stress is a pressure applied equally on all surfaces of the sample and the strain is the resulting change in volume per unit volume. If a sinusoidally varying pressure is superimposed... 

Figure S4.3 The bulk modulus, K or B (a) volume before appHcation of pressure, p, and (b) volume after appHcation of pressure, p...

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