Physical Science International Journal

Dependence of Viscosity and Density of Nigerian Lophira lanceolata Oil (Ochnaceae) on Temperature

J. B. Yerima *

Department of Physics, Modibbo Adama University of Technology, Yola, Nigeria.

J. S. Madugu

Technical Training Services, TSAC Mubi, Nigeria.

P. Timtere

Department of Physics, Modibbo Adama University of Technology, Yola, Nigeria.

Y. M. David

Department of Physics, Modibbo Adama University of Technology, Yola, Nigeria.

*Author to whom correspondence should be addressed.

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Abstract

The viscosity at constant shear rate of 30 rpm and density of Lophira lanceolata oil (LLO) were measured at different temperatures. The viscosity at constant temperature, 285 K was measured at different shear rates. The results show that viscosity decreases with both shear rate and temperature and density decreases with temperature as well as while the cubic expansivity increases with temperature. From viscosity measurements, the following parameters: molar activation energy (G = 5.1 kJ/mol), molar volume (V_m = 11.91 × 10^-3 m³), intermolecular distance (ᵟ = 2.71 × 10^-9 m), consistency index (k = 148.4 Pa) and power index (n = 0.9886 ± 0.0054) were determined. Our results and that from previous works show that LLO may be a non-Newtonian liquid, a good lubricant and coolant in non-vehicle engines, desirable inhibitor of corrosion, and has bio-fuel potentials.

Keywords: Viscosity, density, temperature, Lophira lanceolata oil, shear rate.

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