Abstract: An automatic control system, having a main control system with wireless communication equipment, with a water sprinkling device disposed in an area to be sprinkled with water and adapted to sprinkle water over this area, and water piping installed between a water source and the water sprinkling device, and adapted to distribute water from the water source to the water sprinkling device. A water sprinkling control system is installed on the ground in a position close to the water sprinkling device and adapted to control the water sprinkling device. The water sprinkling control system includes a hydraulic valve disposed in the water piping close to the sprinkling device which has a water channel connecting an inflow passageway with a flow passageway connected to a pilot line. A two-way pilot solenoid valve is connected at one port thereof to the hydraulic valve through the pilot line, and at the other port to a drain piping.

Abstract: Unit panels for constructing tanks and tanks so constructed. The panels include a rectangular plate and four connecting rims. The connecting rims are provided on the four sides of the rectangular plate and extend in the same direction with respect thereto. The forward ends, or edges, of the connecting rims define a flat plane which is perpendicular with respect to the connecting rims; the rectangular plate being inclined with respect to the flat plane and at least two of the connecting rims have rectangular shapes.Various embodiments of the unit panels are provided and include panels wherein two opposing connecting rims are rectangular, the remaining opposing rims being trapezoidal; panels wherein two adjacent connecting rims are rectangular, the remaining adjacent rims being trapezoidal; and panels wherein the rectangular plate is recessed or projections extending in a direction opposite to that of the connecting rims are provided on the rectangular plate.