socalledunitedstates:

Back to Basics: Direct Hydropower

In a modern hydropower installation, a water turbine converts the energy in the moving water into rotational energy at its shaft, which is then converted into electrical energy by the generator that is coupled to the turbine. Next, the electrical energy is converted back into rotational energy by the electric motor of the machine that is being powered. Every energy conversion introduces energy loss.

In an old fashioned hydropower installation, there was only one conversion of energy; A water wheel converted the energy inherent to the water source into rotational energy at its shaft. The same shaft also moved the machinery, so that the only source of significant energy loss occurred in the water wheel itself.

Some small direct hydro powered systems in South America present a strong case for combining the use of modern materials with old fashioned methods of water power mechanization. The higher efficiency of this approach means that less water is needed to produce a given amount of energy. This lowers the cost of hydropower and enables power to be produced by the use of very small streams.

Read more… (Backup in case it’s cloudy in Barcelona)

naughtyhalloweenart:

Nocturna by Miles Teves

justlifehacks:

People don’t often look back on the early 1900’s for advice, but what if we could actually learn something from the Lost Generation? The New York Public Library has digitized 100 “how to do it” cards found in cigarette boxes over 100 years ago, and the tips they give are so practical that millennials reading this might want to take notes.

Back in the day, cigarette cards were popular collectibles included in every pack, and displayed photos of celebrities, advertisements, and more. Gallaher cigarettes, a UK-founded tobacco company that was once the largest in the world, decided to print a series of helpful how-to’s on their cards, which ranged from mundane tasks (boiling potatoes) to unlikely scenarios (stopping a runaway horse). Most of them are insanely clever, though, like how to make a fire extinguisher at home. Who even knew you could do that?

The entire set of life hacks is now part of the NYPL’s George Arents Collection. Check out some of the cleverest ones we could find below. You never know when you’ll have to clean real lace!

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Afficher davantage

historicaltimes:

Lucy Smith and Pauline Ranken of the Ladies’ Scottish Climbing Club climbing the Salisbury Crags in 1908

via reddit

patart-illustrations-stuff:

Joe Spinell and Caroline Munro in MANIAC, the comic book adaptation from Eibon Press

https://www.eibonpress.com/

eartharchives:

They may be our “best friends” but dogs have also emerged as a major threat to wildlife.

ultrafacts:

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