[gzumwalt] does a lot of this, and has recently been working on various versions of a rigid chain mechanism. (Video, embedded below.) A rigid-chain mechanism is one way of fitting a long beam into ...

A new technique, based on a chain reaction of recognition and hybridization events between two sets of DNA hairpin molecules, offers an enzyme-free alternative for the rapid detection of specific ...

It's essential to have a mechanism to guide water down to the ... Others use a rain chain to guide water to a visible rock garden, garden planter, or picturesque fountain. There are many options ...