What if you have a need for liquid nitrogen, but you do not wish to simply order it from a local supplier? In that case you can build your very own pulse tube cryocooler, as [Hyperspace Pirate] is ...

When you rinse your rice before cooking it, do you discard the cloudy water and move on? If so, you are dumping an easy and affordable DIY liquid plant fertilizer down the drain. While rice water ...