Abstract: A static mixing device is described, comprising a flow channel and mixing elements which are distributed over the cross section of the flow channel in the form of flow bodies arranged on a wall extending in the direction of flow and which are each delimited by one tapering deflecting surface which is inclined in relation to the wall and originates from a base extending transversally to the direction of flow and by two guide surfaces which protrude from the wall and which converge in an edge extending transversally to the channel axis on the side of the flow bodies which is opposite of the base.

Abstract: Substantially planar, horizontal athletic fields comprising a substrate provided with a finish or coating of particles of an elastic plastic in the form of flat plates or scales whose length is at least 1.5 times the thickness of the plate or scale and a method of improving the abrupt braking qualities of an athletic field and the said particles.