- Homemade liquid nitrogen generator using Joule Thomson Throttling (homemadeliquidnitrogen.com)
I determined that there was no good tutorial on how the average person can liquefy nitrogen or air. A few references to cryocoolers, which use an internal helium Stirling engine to create a cold head exist, and I even saw one person use this as a means to liquefy nitrogen, allowing the gas to condenses as it passes over the head. This method is cheating because it relies on a self-contained refrigeration unit. I wanted to do this using regenerative cooling just like Carl Linde back in 1895.
- Seattle Neighborhoods: Madrona — Thumbnail History (historylink.org)
Seattle’s Madrona neighborhood overlooks Lake Washington from the eastern rim of the city. Madrona’s hilly origins arise from the Vashon Glacier, which melted 40,000 years ago, leaving flood waters and ice to shape Lake Washington and other Pacific Northwest landmarks. Its first life was as a Native American hunting and fishing ground. Seattle was founded (in 1851), and from the 1880s to 1900, Madrona was overrun by loggers, stump farmers, berry pickers, and realtors. The beginning of the Madrona we know today was the introduction of the Union Trunk Line, which ran from the top of the hill at 34th Avenue and Union Street to Madrona Park and beach.
- Nitrogen (Wikipedia)
Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth’s atmosphere, making it the most abundant uncombined element in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth.