A resource manager of a content management system is configured to receive a client request pertaining to information and to access at least one of a plurality of data servers to execute the client request. The invented pH modifier is used to replace traditional alkaline pH modifiers – hydroxides, carbonates and bicarbonates, such as sodium hydroxide, sodium carbonate, lime and ammonia in anionic flotation processes. A nominal size S andor a nominal distance D of the radioopaque marker elements to each other is known.