See Marangoni Number.
(MNS Test) See Mackay Test.
An empirical test method for determining the effectiveness of oil spill dispersants. The method involves the injection of a high-velocity air stream to potentially disperse oil into water. Also termed the Mackay-Nadeau-Steelman Test. See also Labofina Test.
A unit of viscosity determined by a MacMichael Rheometer. These instruments have been widely used in the industry to determine the viscosity of chocolate. Typical practical values range from about 60 °McM for thin chocolate suitable for pouring into molds, to about 190 °McM for thick chocolate suitable for hand dipping. An estimate of actual viscosity based on a measurement in MacMichael Degrees can be made from the following formula: °McM = (3.4η/100), where η is the viscosity (in mPa·s) referenced to a shear rate of about 7 s−1. Therefore, the thin chocolate just mentioned would have a viscosity of about 1.8 Pa·s, and the thick chocolate about 5.6 Pa·s (both at about 7 s−1). See also MacMichael Rheometer and Rheometer.
An early type of Couette Rheometer in which an outer cylinder (the “cup”) is rotated and torque is measured at the inner cylinder (the “bob”). The flow of fluid in the annulus between the two concentric cylinders rotating at different speeds is caused by the viscous drag acting on the fluid. The torque was originally measured with a torsion spring with an indicator ...