Viscosity is an important property of a lubricant, as it affects the film thickness and, thus, the wear rate of sliding surfaces. It is used for the identification of individual grades of oil and for monitoring the changes occurring in oil while in service. Viscosity increase usually indicates that oil used has deteriorated by oxidation or by contamination, while a decrease usually indicates dilution by lower viscosity oil or by fuel. Kinematic viscosities of the fluids can be measured with ASTM D445 [101] method. The kinematic viscosity is the product of the measured flow time and the calibration constant of the viscometer. The flow time can be measured by measuring the flow of fixed volume of liquid under gravity through a capillary of calibrated viscometer at known temperature. The dynamic viscosity, h, can be obtained by multiplying the kinematic viscosity, n, by the density, p, of the liquid.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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