Estimate values of Bulk modulus at effect of pressure and temperature for mineral oil SAE 46 which it is used in hydraulic systems

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.

The Effect of Organic Matter's Content on the Engineering Properties of Expansive Soils and Treatment Methods

This paper aims at investigating the effect of organic matter content on the engineering properties of the soil. The effect of the organic matter on both the consistency limits and strength have been investigated. The results show that the organic matter increases both the plasticity and the strength of soil. Mathematical formula is presented in which the unconfined compression strength of the soil is related to the organic matter content. It was concluded that increasing the organic matter content increases the displacement corresponding to the maximum shear stress. In addition, the effect of the organic matter has been studied and the results show that the organic matter increases the compressibility of the soil. Stabilizing the soil with cement has been investigated as well. The results show that adding the cement to the soil improves the strength of the soil and decreases its swelling potential. Depending on the organic matter content, a mathematical formula is presented to determine the required cement ratio to treat the soil to decrease its swelling potential.