Rolling-ring drives are friction drives that convert the constant rotary motion of a plain shaft into a traversing action that moves an attached carriage. Used in positioning and reciprocating ...

How gravity causes a perfectly spherical ball to roll down an inclined plane is part of elementary school physics canon. But the world is messier than a textbook. Scientists in the Harvard John A.

(A1) Asymmetric driving principle PMP and its normal force analysis. (A2) Force and motion analysis of the PMP. (B1) Schematic diagram of the rack-and-pinion mechanism. (B2) Schematic diagram of the ...

The Nature Index 2025 Research Leaders — previously known as Annual Tables — reveal the leading institutions and countries/territories in the natural and health sciences, according to their output in ...