If a sol of colloidal ferric hydroxide is added to sea water, or if the hydroxide is formed in sea water by adding a solution of an iron salt, the aggregated molecules of hydroxide coalesce to form flocs which fall rather rapidly as a precipitate. When several thousand mg. of iron are added per cubic metre of sea water, flocculation is immediate; on adding 300-500 mg. Fe per m.3 in sufficiently...

This paper constructs a dynamic game model to address the following groundwater management problem, where quantity and quality of the water are taken into account. A group of farmers overexploits a groundwater stock and causes excessive pollution. A water agency wishes to regulate the farmers' activity, in order to reach a minimum level of quantity and quality but is subject to a budget constra...

The “measuring with jugs problem” involves pouring water between jugs to measure out a specific quantity of water. The object is to find the proper sequence of fill operations, pour operations (from one jug to another) and emptying operations to arrive at the desired quantity of water which may be in either jug. In the past, solutions to this puzzle have always involved creating a series of ope...

A fuzzy control irrigation system for cotton field is presented in this paper. The system is composed of host computer, slave computer controller, communication module, soil water sensors, valve controllers, and system software. A fuzzy control model is constructed to control the irrigation time and irrigation quantity for cotton filed. According to the water-required rules of different cotton ...