viscosity density ratio
121Sound — This article is about audible acoustic waves. For other uses, see Sound (disambiguation). In a drum sound is produ …
122Honeycomb structure — For other uses, see Honeycomb (disambiguation). An image of aluminum honeycomb structure …
123Plasma (physics) — For other uses, see Plasma. Plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation. The colors are a result of relaxation of electrons in excited states to lower energy states after they have recombined… …
124Electric motor — For other kinds of motors, see motor (disambiguation). For a railroad electric engine, see electric locomotive. Various electric motors. A 9 volt PP3 transistor battery is in the center foreground for size comparison. An electric motor converts… …
125Prandtl number — The Prandtl number mathrm{Pr} is a dimensionless number approximating the ratio of momentum diffusivity (kinematic viscosity) and thermal diffusivity. It is named after the German physicist Ludwig Prandtl.It is defined as::mathrm{Pr} = frac{… …
126Extraction of petroleum — Pumpjack on an oil well in Texas The extraction of petroleum is the process by which usable petroleum is extracted and removed from the earth. Contents 1 …
127History of the petroleum industry in Canada (oil sands and heavy oil) — Canada s oil sands and heavy oil resources are among the world s great petroleum deposits. They include the vast oil sands of northern Alberta, and the heavy oil reservoirs that surround the small city of Lloydminster, which sits on the border… …
128Blood — For other uses, see Blood (disambiguation). Human blood smear: a – erythrocytes; b – neutrophil; c – eosinophil; d – lymphocyte …
