Drying Out Microbe-Filled Droplets

Ocean sprays, coughs, and sneezes are just a few of the ways that droplets full of bacteria and salt can get aloft on a breeze. How do these bacteria stay viable even as their droplet evaporates? That’s the question behind this video’s research.

When a bacteria-laden droplet or a salt-laden droplet dries, the evaporating droplet’s contact area shrinks, leaving behind only a concentrated lump of bacteria or salt. But when droplets contain both salt and bacteria, the drying droplet’s contact line gets pinned, leaving a larger area stain. The bacteria’s presence seems to promote crystallization of the salt, which–in turn–traps water in isolated spaces, perhaps helping the bacteria stay viable longer. (Video and image credit: R. Ran et al.)

How does a droplet dry when space is confined?

Experiments by B. Sobac and colleagues using interferometry and controlled humidity track the evaporation of binary liquid droplets in a 2D geometry.

Useful for studying droplet evaporation.

🔗 https://journals.aps.org/prfluids/abstract/10.1103/9zdm-drvp

#FluidDynamics #Droplets #Evaporation #SoftMatter #TransportPhenomena

“Crystal Garden – Seasons”

In this latest project, the Beauty of Science team explores colorful crystallization as chemicals precipitate out of evaporating solutions. The variety of shapes and colors is incredible. To see many more of these crystalline “gardens,” check out the video below and the project’s webpage. (Video and image credit: W. Zhu/Beauty of Science; via Colossal)

https://vimeo.com/1155318039?fl=pl&fe=cm

The Balvenie

Photographer Ernie Button explores the stains left behind when various liquors evaporate. This one comes from a single malt scotch whisky by The Balvenie. The stain itself is made up of particles left behind when the alcohol and water in the whisky evaporate. The pattern itself depends on a careful interplay between surface tension, evaporation, pinning forces, and internal convection as the whisky puddle dries out. (Image credit: E. Button/CUPOTY; via Colossal)

#alcohol #deposition #evaporation #fluidDynamics #fluidsAsArt #physics #science #surfaceTension

Growing Salty

Ngangla Ringco sits atop the Tibetan Plateau, breaking up the barren landscape with eye-catching teal and blue. This saline lake sits at an altitude of 4,700 meters, fed by rainfall, Himalayan runoff, and melting glaciers and permafrost. The lake, like many inland bodies of salt water, has no outflow. Instead, water evaporates from the lake, leaving behind any salts that were dissolved in it. Over time, those left-behind salts build up and make the lake ever saltier. (Image credit: NASA; via NASA Earth Observatory)

#astronaut #dissolution #evaporation #fluidDynamics #physics #salinity #satelliteImage #science

Dissolution and Crystallization

A colorful assortment of salts dissolve and recrystallize in this microscopic timelapse video by retired engineer Jay McClellan. Every step is a gorgeous rainbow of color as the cobalt, copper, and sodium chlorides dissolve, mix, and change. Though we don’t see what’s going on in the water, fluid dynamics are a critical component of both dissolution and crystallization. In the former, concentration gradients change the water’s density, driving buoyant flows. For the latter, crystallization comes out of evaporation, where surface tension often determines where solid particles get left behind. (Video and image credit: J. McClellan; via Colossal)

#buoyancy #dissolution #evaporation #fluidDynamics #fluidsAsArt #physics #science

→ How Much Water Do AI Data Centers Really Consume?
https://spectrum.ieee.org/ai-water-usage

“Just as human bodies cool themselves by sweating, data centers are often cooled by water #evaporation—a process that dissipates heat and results in water being lost to the atmosphere, and thus being counted as "consumed."”

“Beyond the water that cools the servers, #data_centers indirectly contribute to water use through the #electricity generation needed to power their operations.”

#AI #cool #heat #water #power