Month: March 2021

Enlarge / A future green jet fuel? (credit: Picture Alliance/Getty Images)

For many applications, liquid fuels remain the most practical energy supply—applications like aircraft and large ships being obvious examples. It's possible to avoid using fossil fuels for these applications, since there are many ways to produce biofuels. But we can't produce biofuels at a competitive price, leaving fossil fuels as the dominant option.

A group of US-based researchers has therefore looked into the prospect of converting food waste into jet fuel. Chemically, the results are excellent, producing material that can be blended with a bit of standard jet fuel to meet all regulatory standards. Economically, the situation is not nearly so great, only working at prices that were prevalent over five years ago. But the fact that the waste would otherwise put methane in the atmosphere as it decays more than offsets the carbon dioxide produced by the jet fuel in the blend. So a price on carbon could change the equation.

Food (and other stuff) to fuel

The work here is focused on what are called "wet wastes," which include things like food waste, animal manure, and sewage. As you might expect, we produce a lot of this stuff, with the authors estimating that its total energy content is roughly equivalent to 10 billion gallons of jet fuel every year. Due to the amount of water present, it's extremely energy-intensive to directly convert this waste to any sort of fuel, since the water has to be discarded. It is, however, possible to put the waste in an oxygen-free environment and have bacteria convert it to methane.

Enlarge / The bacteria (yellow) live inside a larger eukaryotic cell. (credit: MAX PLANCK INSTITUTE FOR MARINE MICROBIOLOGY)

Deep in Switzerland's Lake Zug swims a microorganism that has evolved a strange way to "breathe." A team of researchers discovered a novel partnership between a single-celled eukaryote—an organism with a clearly defined nucleus holding its genome—and a bacteria that generates energy for its host. But instead of using oxygen to do so, it uses nitrate.

“This is a very weird, [newly discovered] organism,” said Jana Milucka, a biologist at the Max Planck Genome Center in Cologne and senior author on the resulting paper, published in Nature in early March.

The team named the bacteria Candidatus Azoamicus ciliaticola, meaning "nitrogen-friend that lives inside a ciliate." Its partner, the ciliate, is a microorganism that moves around using cilia, tiny hair-like protrusions outside their cell walls. The host organism is part of a group of ciliates called Plagiopylea.

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  How many Radeon RX 6700XT graphics cards did AMD produce? Well, at least one. [credit: Sam Machkovech ]

Look, I'll level with you: reviewing a GPU amidst a global chip shortage is ludicrous enough to count as dark comedy. Your ability to buy new, higher-end GPUs from either Nvidia or AMD has been hamstrung for months—a fact borne out by their very low ranks on Steam's gaming PC stats gathered around the world.

As of press time, AMD's latest "Big Navi" GPUs barely make a ripple in Steam's list. That's arguably a matter of timing, with their November 2020 launch coming two months after Nvidia began shipping its own 3000-series GPUs. But how much is that compounded by low supplies and shopping bots? AMD isn't saying, and on the eve of the Radeon RX 6700's launch, the first in its "Little Navi" line, the company's assurances aren't entirely comforting.

In an online press conference ahead of the launch, AMD Product Manager Greg Boots offered the usual platitudes: "a ton of demand out there," "we're doing everything we can," that sort of thing. He mentioned a couple of AMD's steps that may help this time around. For one, AMD's "reference" GPU model is launching simultaneously with partner cards, so if the inventory is actually out there (we certainly don't know), that at least puts higher numbers of GPUs in the day-one pool. Also, Boots emphasized stock being made available specifically for brick-and-mortar retailers—though he didn't offer a ratio of how many GPUs are going to those shops, compared to online retailers.