A sweatband designed to be worn on a user for usage in a variety of sporting activities. A density-correction-value calculator calculates a density correction value from the first and the second densities. The ore is digested by producing feeding a suspension produced from milled bauxite ore and concentrated aluminate liquor to a plant with a series of autoclaves and a series of regulators supplying tubular reheaters across the autoclaves with steam. When M is Eu, the compound emits a yellow-green light upon being excited by a blue light andor an ultra-violet light. The method also includes placing a source in the body of water.