Shear thinning
Overview
 
Shear thinning is an effect where a fluid's viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...

—the measure of a fluid's resistance to flow—decreases with an increasing rate of shear stress
Shear stress
A shear stress, denoted \tau\, , is defined as the component of stress coplanar with a material cross section. Shear stress arises from the force vector component parallel to the cross section...

. Another name for a shear thinning fluid is a pseudoplastic. This property is found in certain complex solutions, such as lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

, ketchup
Ketchup
Ketchup is a sweet-and-tangy condiment typically made from tomatoes, vinegar, sugar or high-fructose corn syrup and an assortment of...

, whipped cream
Whipped cream
Whipped cream is cream that has been beaten by a mixer, whisk, or fork until it is light and fluffy. Whipped cream is often sweetened and sometimes flavored with vanilla, in which case it may be called Chantilly cream or crème Chantilly ....

, blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

, paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...

, and nail polish
Nail polish
Nail polish, or nail varnish, is a lacquer applied to human fingernails or toenails to decorate and/or protect the nail plate.-History:...

. It is also a common property of polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

 solutions and molten polymers. Pseudoplasticity can be demonstrated by the manner in which squeezing a bottle of ketchup, a Bingham plastic
Bingham plastic
A Bingham plastic is a viscoplastic material that behaves as a rigid body at low stresses but flows as a viscous fluid at high stress. It is named after Eugene C. Bingham who proposed its mathematical form....

, causes the contents to undergo a change in viscosity.
 
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