make the best decisions they can
I would recommend an HPLC and a competent analytical chemist to gather data and decide whether or not a batch is safe to consume.
make the best decisions they can
I would recommend an HPLC and a competent analytical chemist to gather data and decide whether or not a batch is safe to consume.
This has been posted to a bunch of different communities, and I’m gonna be a stick in the mud each time.
I’m a process chemist. I do this for a living. I’ve made kilo-scale batches of pharmaceuticals at work that have gone through the regulatory process and made it into people. I went to school for ten years to do this.
This is a colossally dangerous thing.
Every time you run a chemical synthesis, you generate impurities. Slightly different temperatures, concentrations, reagent quality, and a million other things will vary the identities and concentrations of those impurities in your product.
The nature of biochemistry is that most compounds, even at very small concentrations, can have effects. Usually bad ones. So drugs have tight specs on how much of each potential impurity can be present. Usually it’s in the 0.1% range, but sometimes a lot lower.
Detection of impurities at that level cannot be done with ‘hacker’ gear in your garage. So if you do this, you’re going to be taking unknown quantities of unknown impurities.
There are trade-offs. If you’re definitely gonna die without the medicine, then the worst that can happen is you die faster, or more painfully. If it’s medicine to maintain quality of life, then you might die fast and painfully.
I’m not saying the current system is good at all. Medicine is too expensive. It shouldn’t be limited by right wing nutjobs. Those things are true. Those things require a solution.
This is not a good solution.
Unless our ability to cram delta-V into a spacecraft goes way beyond what seems possible now with chemical rockets, a trip to the moon is always gonna involve a few days of coasting through space. That’s always going to take more preparation than a transatlantic flight.
I sort of feel bad about raining on the parade of the person distilling isopropanol in his garage earlier, but it really is dangerous.
But most of us chemists also need to be reminded of it. To the point that someone had to write a paper whose entire point is “don’t distill isopropanol”.
Please, don’t do this thing.
The issue with isopropanol peroxide formation is that exposing it to air – even when just using it, like when you’re cleaning parts – starts the process. The air in the head space of your containers is also enough to form them over time. You don’t necessarily need to see solids in the containers for it to be dangerous, since they’ll crystallize out as you concentrate the solution during distillation.
It’s also a numbers game. It probably won’t explode the first time you do it. But there’s a chance each time. Do it enough, and you’ll have an incident.
There are chemical reductants that can clear peroxides. For industrial scale isopropanol distillation, I’m not sure what they use. It may be that they just never distill down to the point that peroxides concentrate to a dangerous level.
I love EnF. But I assure you, organic peroxide formers are scarier.
No no no no no.
I’m a chemist. Organic chemistry PhD, now a process chemist in the industry. I do this for a living. Do not distill isopropanol that’s been exposed to air for any meaningful length of time.
Isopropanol slowly reacts with oxygen in the air to generate peroxides that, when you concentrate them down, EXPLODE. Source. Sorry, not an open access journal. But please take my word for it.
Unless you have a way of confirming the peroxide levels in your isopropanol are near zero, do not concentrate it down by distillation. You’ll blow up your glassware, which will probably expose what you’re distilling to your heat source, which will generate a secondary fireball.
PLEASE do not do this.
I feel bad for laughing at this
got lucky
That is not how I’d characterize 2016 at all. Also, I would like to refer you to argument number two.
Why on earth are we still listening to Nate Silver?
A lot of the Apollo work also got done in basically one administration (Johnson largely continued JFK’s policies). As soon as Nixon was in charge, NASA got gutted, and then they only had the resources for shuttle. Later Apollo missions got cancelled because Nixon thought the money was better spent killing more Vietnamese people.
Switching administrations means vastly changing policies, if for no other reason than the new boss hates the old boss. SLS “succeeded” (got hardware made and launched, at least) where Constellation failed partly because they buttered everyone’s bread in the right way.
HLS is dumb. SLS is dumb. But similarly to Commercial Cargo and Crew, it survived administration changes partly because NASA wasn’t directly at the helm, so the new guys didn’t just hit the big red stop button.
In the entire history of NASA, they’ve never manufactured any boosters for themselves. Redstone was from the army. Titan, also military. Saturn I and V were designed by NASA but contracted to big aircraft manufacturers as contractors. Shuttle was Boeing / Rockwell for the orbiter, ATK for the boosters. SLS is basically all the Shuttle contractors, again. (That was the point.)
I hear what you’re saying. But NASA would need to spin up an entire company from scratch to build their own rockets. That’s not what their mandate is, and it’s not what they’re good at.
Drawbacks are mostly the economics of it. You have to convince people to put time and energy into turning waste into monomers. If the monomers you get from crude oil are cheaper, you’ve got an uphill battle.
The catalysts can be complex, but the good ones are really simple. The zinc one in this article is pretty easy to understand. Ours was an organic molecule, but a really abundant and cheap one. (We could easily recover and re-use the catalyst, too, which I also doubt most of the metal salt catalysts are capable of). Part of the project was optimizing that catalyst. We found ones that worked a little better, but were like 10x as expensive. So we just used a little more of the simple one and figured out how to use it over and over.
I worked on a similar (but competing) technology to this one for a few years. Depolymerization is absolutely the way forward for most polymer recycling.
For most uses, manufacturers want plastic that’s colorless and has good physical properties. Melting down clear plastic can work, but it degrades the polymers in hard-to-control ways. And if there’s any pigment in the plastic, forget about it.
If you break down polymers into their constituent monomers, you’ve turned a polymer process into a chemical process. Polymers are hard to work with. Chemicals are, comparatively, pretty easy. You can do a step or two to extract all the color and impurities, then re-polymerize the cleaned up material and get plastic that’s indistinguishable from brand new.
If your depoly process is good, it can distinguish between different polymers, so you can recycle mixed waste streams. Ours was even pretty good at distinguishing nylon from PET, which I sorta doubt the zinc process will be. But hey, more competition in this space is gonna be good for the world.
It was a scan during upload to their cloud photos system. Everyone else does it on their servers, Apple was going to run the scan before so they didn’t have to ever have them. To not have images scanned before upload, a user would just not have to use their cloud photos service.
The messaging was really badly handled. They almost certainly just scan all the same photos on their servers instead now.
A better question would be why Microsoft went with a nonstandard layout when they designed the Xbox controller. Nintendo had been using the A-to-the-right layout since 1990.
The industry standard is HPLC (high performance liquid chromatography). Those things go for tens of thousands of dollars up front, plus maintenance and consumables.
If there was a less costly way of doing it, you bet companies would have settled on that by now.