Day: January 24, 2023

Broken Genes And Scrambled Proteins: How Radiation Causes Biological Damage

January 24, 2023 by 31 Comments

If decades of cheesy sci-fi and pop culture have taught us anything, it’s that radiation is a universally bad thing that invariably causes the genetic mutations that gifted us with everything from Godzilla to Blinky the Three-Eyed Fish. There’s a kernel of truth there, of course. One only needs to look at pictures of what happened to Hiroshima survivors or the first responders at Chernobyl to see extreme examples of what radiation can do to living tissues.

But as is usually the case, a closer look at examples a little further away from the extremes can be instructive, and tell us a little more about how radiation, both ionizing and non-ionizing, can cause damage to biochemical structures and processes. Doing so reveals that, while DNA is certainly in the crosshairs for damage by radiation, it’s not the only target — proteins, carbohydrates, and even the lipids that form the membranes within cells are subject to radiation damage, both directly and indirectly. And the mechanisms underlying all of this end up revealing a lot about how life evolved, as well as being interesting in their own right.

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A cartoon vehicle is connected to two wires. One is connected to an illustrated Li anode and the other to a γ-sulfur/carbon nanofiber electrode. Lithium ions and organic carbonate representations float between the two electrodes below the car. A red dotted line between the electrodes symbolizes the separator.

Lithium Sulfur Battery Cycle Life Gets A Boost

January 24, 2023 by 11 Comments

Lithium sulfur batteries are often touted as the next major chemistry for electric vehicle applications, if only their cycle life wasn’t so short. But that might be changing soon, as a group of researchers at Drexel University has developed a sulfur cathode capable of more than 4000 cycles.

Most research into the Li-S couple has used volatile ether electrolytes which severely limit the possible commercialization of the technology. The team at Drexel was able to use a carbonate electrolyte like those already well-explored for more traditional Li-ion cells by using a stabilized monoclinic γ-sulfur deposited on carbon nanofibers.

The process to create these cathodes appears less finicky than previous methods that required tight control of the porosity of the carbon host and also increases the amount of active material in the cathode by a significant margin. Analysis shows that this phase of sulfur avoids the formation of intermediate fouling polysulfides which accounts for it’s impressive cycle life. As the authors state, this is far from a commercial-ready system, but it is a major step toward the next generation of batteries.

We’ve covered the elements lithium and sulfur in depth before as well as an aluminum sulfur battery that could be big for grid storage.

Bend It Like A Carpenter

January 24, 2023 by 18 Comments

We’ve always known, in theory, there are ways to bend wood, but weren’t really clear on how it worked. Now that we’ve seen [Totally Handy]’s recent video, we’ve learned a number of tricks to pull it off. Could we do any of them? Probably not, any more than watching someone solder under a microscope means you could do it yourself with no practice. But it sure made us want to try!

All of the techniques involve either water or steam, but we were fascinated with the cuts that make the wood almost into a flexible mesh. There are several tricks you can pick up, too, if you watch carefully. In “wordless workshop” form, there’s no real audio or text, just watching this guy make some really interesting wood pieces.

It looks like you could do some of this with pretty ordinary tools, although he does use a table saw, a router, and a few types of sanders. There isn’t anything too exotic, although we weren’t entirely clear on how the steam tube worked. If you have a cheap CNC machine, those usually can do a pretty good job on wood, and we wondered if you couldn’t pull off some of these tricks that way, too.

We love projects made with wood that look like they were impossible to make. Don’t forget wood as a construction material. Combined with 3D printing and other techniques, it can make some impressive things.

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