Hydraulic system was designed and installed to estimate values of Bulk modulus within the range of
pressure between 20 bar to 230 bar and temperature between 5° C to 90° C; these limits are the widest
range in which it operates hydraulic systems .
In this research the mineral oil (SAE 46) is heated
(indirectly method) and then pressed into a pipe with large thickness compared with internal diameter so
as to ensure that the results will not be affected by the elasticity of the pipe material. The results for the
characteristics‚the pressure and temperature have been indicated by gages installed on the line of
hydraulic circuit while taking readings compressibility through indicator tube. It was concluded that the
temperature of mineral oil have an effective impact on the Bulk modulus values even at lower
temperatures lower than 50° C and the sloop (of the relation curve between Bulk modulus and pressure)
is reduced with temperature increase. it was also estimated that values of Bulk modulus are volatileat
pressures less than 100 bar with increasing temperatures for this mineral oil.
errite (x=0.5) was prepared by a well-known conventional ceramic double sintering method (CCDS). Force constant K was calculated for tetrahedral and octahedral sites. The elastic constant C11, bulk modulus B , longitudinal and shear wave velocities w
ere calculated. Threshold frequency for electronic transition was determined using IR spectra. In addition, the drift mobility for tetrahedral and octahedral sites, as well as magnetic dipole moment changes for bond were determined. The area beneath endothermic peaks was correlated to the weight change TG%. On the other hand, the heat capacity under constant pressure CP was correlated to sample treatment temperature. It has been noticed that the CP has a critical value at 175.
