Instrumentation 74 yield strength

In practice, the compression of fluids in large-volume systems is performed at pressures up to 1.4 GPa, or 1.8 GPa at the very most. The reason is that standard construction steels and alloys for the various components of a high-pressure set-up have maximum yield strengths of 2 GPa. The design and operation of a 1.4 GPa set-up is now comparatively simple, but a 2 GPa instrument requires specialized expertise. In this range of pressure, two separate regions must be distinguished pressures up to —600 MPa, and pressures up to 1.4 GPa. 

Tensile yield strength (MPa) Elongation at break (%) Hardness (Shore D) Instrumented Impact (-30°C) (Energy at Max. load, J) Notched Izod... 

An atlas of NMR spectra (the OCAD version 7 from April 2004 contained 1391 NMR spectra) of the OCAD has been compiled with the assistance of dedicated laboratories worldwide. The efforts of the laboratories and the OPCW have yielded a useful high-quality NMR spectral database. The only factor limiting its usefulness could be the difference of the instruments (in magnetic field strength and resonance frequency) that were used, because the resonance frequency may affect the spectrum appearance, in particular, in NMR. However, this is not considered to be a serious problem because many of the spectra were recorded on 300-400-MHz instruments whose spectra do not differ much from those recorded at 200 or 500 MHz. The difference between the two extremes may be larger. The OPCW requires that all spectra to be included in the OCAD be evaluated and validated. 

In the temperature range where the carrageenin is normally employed, viscosity characteristics become dependent on temperature, other solutes, and mode of observation. In a system like this it would be more appropriate to speak of consistency, fluidity, or some similar subjective term, and measuring instruments should be selected to reflect the property desired. The texture of a gel is a combination of strength and elasticity, both of which can be measured. The mouth feel of a paste is a combination of yield, viscosity, and melting temperature, the first two of which can be determined by measurements of thixotropic flow. Of particular significance is that measurements assuming Newtonian viscosity do not show the thixotropic characteristics that influence sensory experience. 

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