Gold medalist Katie Ledecky of the US poses with her medal at the women's 1500m freestyle victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona, July 30, 2013. [Photo/Agencies]
Geng Jiasheng, 54, a national master technician in the manufacturing industry, is busy working on improvements for a new removable environmental protection toilet, a project he has been devoted to since last year.