Buoyancy modulus

The buoyancy modulus (Bu) is defined as the ratio of the density difference to the liquid density ... 

Physical Properties. Bast and leaf libers are stronger thicker tensile strength and modulus of elasticity but lower in elongation (extensibility) titan cotton. Vegetable libers arc stiffer bin less tough than synthetic libers. Kapok and coir are relatively low in strength kapok is known Ibr its buoyancy. 

TMA consists of a quartz probe which rests on top of a flat sample (a few mm square) in a temperature controlled chamber. When set up in neutral buoyancy then as the temperature is increased the probe rises in direct response to the expansion of the sample yielding thermal expansion coefficient versus temperature scans. Alternatively, with a penetration probe under dead loading a thermal softening profile is obtained (penetration distance versus temperature). Although this is a simple and versatile experiment, it gives only a semi-quantitative indication of mechanical modulus versus temperature. 

A typical value of Poisson s ratio for a syntactic foam is 0.15, which would give the Yoimg s modulus to be about 2K, or K is about EI2. Typically, the upper limit on volumetric strain imder service conditions is between 1 and 2%, which corresponds to about 65-70% of the critical stress corresponding to the onset of collapse or crushing of foam. This loss of buoyancy will be instantaneous upon the apphcation of hydrostatic pressure. 

Elastic Modulus. The elastic modulus was determined by combining the results of acoustic-wave velocity and density (aqueous buoyancy) measurements. 

Although only isothermal systems are considered in this section, the hydrodynamics in a real system may be influenced by thermal gradients in the mold. The temperature difference between the molten steel in the mold and the issuing steel jet is at most 20K, and the bulk modulus of steel is quite small. Therefore, natural convection force due to temperature stratification is small compared to the inertia force of the steel jet and the buoyancy force acting on argon bubbles in the jet. 

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