Abstract: Described are abrasive silica particles suitable for use in a dentifrice composition, the particles comprising particles of a first abrasive silica in an amount of at least 90 wt % relative to the total weight of the abrasive silica particles; and particles of a second abrasive silica in an amount of up to 10 wt % relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d50) of the particles of the second abrasive silica is less than the weight median particle diameter (d50) of the particles of the first abrasive silica and from 15% to 70% of the d50 value of the particles of the first abrasive silica. Dentifrice compositions comprising such particles and methods of preparing such particles are also described.

Abstract: A towable buoy having a tow point for connection to a tow cable of a vessel, wherein the position of the tow point is translationally moveable with respect to the remainder of the buoy. Also, a method of operating the towable buoy.