Abstract: A method of producing a precipitated calcium carbonate (pcc) product which has a coarse crystalline form which comprises the steps of: (a) preparing a suspension in an aqueous medium of calcium hydroxide particles which partially dissolve as calcium ions in the aqueous medium, the aqueous medium also incorporating an agent which promotes release into solution in the aqueous medium of calcium ions from the calcium hydroxide; (b) adding carbon dioxide to the aqueous medium to react with the calcium ions therein to produce a suspension in the aqueous medium of a precipitate of calcium carbonate crystals; (c) concentrating the suspension of the precipitate by a dewatering process; and (d) adding to the suspension of the precipitate a dispersing agent for the precipitate; wherein in step (a) the calcium hydroxide particles of the suspension of calcium hydroxide particles have a specific surface area measured by the BET nitrogen method of less than 33 m2/g and the said agent comprises a water soluble organic c

Abstract: Induction heating apparatus for heating an elongate metal workpiece of predetermined width generates time varying magnetic fields which produce longitudinal eddy current distributions across the width of the workpiece having cosine and sine profiles. The amplitude of these profiles is not necessarily uniform across the width of the workpiece and the spatial period of these profiles across the workpiece width are chosen to ensure that the line integral across the workpiece of the eddy currents is zero. In this way a desired heating profile across the width of the workpiece can be maintained.

Abstract: The present invention is a vacuum cleaner and recharging assembly including a vacuum cleaner having a motor, a housing enclosing the motor, a fan driven by the motor for producing a vacuum, a canister for at least the reception of air and foreign matter drawn into the canister in response to the vacuum produced by the fan, and a power source for powering the motor. The assembly also includes a charging unit cooperable with the vacuum cleaner for charging the power source. The assembly further includes means for removably securing the vacuum cleaner to the charging unit when the vacuum cleaner engages the charging unit.

Abstract: In the induction heating of rotationally symmetrical workpieces, the workpieces are passed through the treatment region with magnetic flux in the region parallel to the axis of symmetry of each workpiece as it passes through the treatment region. In order to obtain uniform heating of the workpieces, flux modifying members are provided which are arranged so that the resultant distribution, across the workpiece transversely of the axis thereof of the magnetic flux density in the axial direction is substantially inversely related to the distance from the axis of rotational symmetry of the workpiece.

Abstract: A container, which is adapted for nesting together with similar containers during transport and storage thereof, comprising an exterior surface which bears printed indicia. The printed indicia is carried on one or more portions of the container that have been formed so that surfaces of such printed portions lie in a plane below the plane of the surrounding surface area. Thermoplastic foam egg cartons such as polystyrene cartons are especially suitable as containers constructed in accord with the invention.