Abstract: A method includes storing, in computer memory, a tessellation comprising a plurality of tiles corresponding to a plurality of geographical regions. The plurality of tiles are stored with travel times in a plurality of transportation modalities across a plurality of edges of the plurality of tiles. The method also includes storing, in the computer memory, associations between a plurality of points of interest and corresponding tiles of the plurality of tiles based on locations of the plurality of points of interests relative to the plurality of geographic regions, determining, by one or more processors, a first set of the plurality of tiles reachable from a first tile of the plurality of tiles in up to a first total travel time based on the travel times across the plurality of edges, and identifying, by the one or more processors, a first set of the plurality of points of interest associated with the first set of the plurality of tiles.

Abstract: In a process of making sodium perborate, crystallization is performed in the presence of an organic polymer with a high potential content of free carboxylic groups derived from maleic anhydride, selected from the copolymers of maleic anhydride with an organic compound with an ethylene bond. The process is applicable to obtaining sodium perborate crystals of high apparent density of good resistance to abrasion and of limited, relatively high granulometric size.