Overview. Kidney stones are also known as calculi (plural), or calculus (singular). When it is in the kidney, it is a renal calculus. The tube draining the kidney to the bladder is the ureter, and a stone in the ureter is a ureteral calculus. It is estimated that 20% of us will have a kidney stone in our lifetime.
âIt wasn't long ago that sprayers were a niche product,â says Cory Venable, John Deere product manager. âNow they have become an essential product for effective crop production. More and more producers are seeing the value and return on investment that a self-propelled sprayer offers.
The first self-propelled vehicle. French Army Captain Cugnot was one of the first to successfully employ a device for converting the reciprocating motion of a steam piston into a rotary motion by means of a ratchet arrangement. A small version of his three-wheeled fardier Ã  vapeur (steam dray) was made and used in 1769 (a fardier was a massively built two-wheeled horse-drawn cart for transporting very heavy equipment, such as cannon barrels).