The grad student doesn't want to be tempted by the software industry offering to quintuple his salary.
(Disclosure: Former physics grad student, who tended a similar optics bench).
https://de.aliexpress.com/w/wholesale-frequency-comb-laser.h...
The varying mirror cavity is today's innovative step, plus the computation to identify atoms and molecules from the observation of color absorption.
[0] https://www.nist.gov/news-events/news/2013/07/nist-shows-how...
https://en.m.wikipedia.org/wiki/Inductively_coupled_plasma#A...
Apparently, watching an Aussie with a backyard shed full of mysterious chemicals and reagents has me assuming that any mysterious, unmarked liquid that needs to be identified is probably explosive.
If you heat water and alcohol to 80°, measurements would indicate ~100% alcohol.
You won’t know the right temperature unless you know what substance it is.
Edit: I guess you might also have stuff which reacts below their vaporising temperature.
It would be nice if there were general purpose gas measurement sensors that could identify more gasses rather than being specialized to a specific gas. Could this be done by replacing the circuitry of a typical evaluation board with an interface to something like an NVidia Jetson Orin Nano?
[1] https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=90...
Problem with general purpose spectroscopic measurements is that you need a broadband source and detector. This adds complexity compared to a targeted wavelength range.
https://www.bruker.com/en/products-and-solutions/infrared-an...
This paper is obviously trying to go much further. But if you just want to buy a tricorder, you can
That said this is getting into Christmas present territory:
https://www.ebay.com/itm/167319991806?_skw=handheld+raman+sp...
It’s one banana, Michael. What could it cost? Ten dollars?
Kids? I bought a MacBook Air for an internet friend of around 2 months because I was so offended by the fact that they didn't own a good computer.
My performance standards are higher for myself of course, but the goal was just to get them any form of macOS.
(They did in fact end up liking it a lot better than Windows)
There are open questions on if recycling plastic is worth bothering with at all, but that is a different debate.
Here's the machinery doing it.[1] It's just using RGB and IR cameras; they're not using lasers to vaporize samples and analyze the spectrum. That would be both overkill and a fire hazard.
Overview of modern waste handling.[2] Most of the separation is entirely mechanical, with screens, vibrators, rotating drums, and air blasts. But HDPE and PET plastics are separated using infrared sensing.
You could tell when people farted.
This was used to great effect in the Kenny VS Spenny episode, Who Can Blow the Biggest Fart: https://youtu.be/ash2NzL1IHo
(It’s a Canadian show)
If you think about it, the oil just took a detour into being a water bottle or whatever for a little while on it's way to the power plant. I really can't imagine we'll be at 0 hydrocarbon electricity grid any decade soon and burning garbage (and instead of "recycling" plastic) seems to be a perfectly reasonable thing to do if you can do it cleanly in a power plant.
Is it not possible to make a very thin slice of it for analysis?
i love this idea. i cant believe how tiny the marked recycling categories are on the containers, i can barely see them. i always wondered how they even achieve this at the town recycling center.
There’s a lot of automation in the space, and none of it uses the markers
They don't. A huge proportion is never recycled at all.
https://ntrs.nasa.gov/citations/19720026861
and is still going on
https://iopscience.iop.org/article/10.1088/1748-9326/ab9cfd
https://idstch.com/security/lidar-technology-revolutionizing...
I think in those cases you know what the pollutant is that is in a gas that you know what it is and want to make a quantitative determination whereas the system described in that paper is supposed to make sense of some random gas.
1. It's harder to communicate with drivers with tinted windows and to check for their attention. This especially affects pedestrians and bicyclists who have to take pains to make sure they have a driver's attention before making their move, even when they have right of way.
2. You can't prosecute someone for a moving violation if they weren't identified as driving the car (because if a car is stolen for a joyride you don't want the original owner losing their license). Overly tinted front windows make it harder to consistently ID a driver, and let people get away with reckless driving.
3. Frankly it's annoying to not be able to see through cars. It makes certain turns iffier (because you can't see through the parked cars to identify oncoming traffic) and it makes it harder to predict a slow down if you can't see through the back windshield of the huge SUV completely obstructing your line-of-site. Obviously you should be maintaining a sufficient stopping distance to safely slow down, but that doesn't make it nicer to be able to see the slowdown/stop coming a bit before it arrives.
https://en.wikipedia.org/wiki/On-board_diagnostics
is that the engine control unit in your car is monitoring the operation of the engine and thinks it is in spec. If the computer says it is OK, it is OK, at least in most states.
For years there has been talk about an OBD-III that would use the cellular network or something so your car can narc on you if it is out of spec
https://www.hotrod.com/features/obd-iii-the-proposed-future-...
This has been stuck in purgatory with all the other proposals for universal telematics not least because of privacy concerns plus cell phone carriers being uninterested in anything other than "what's convenient for us" coverage.
The downside of this method (or upside, I guess, depending on where you stand), over the sniffer method, is that this is trivially bypassed. My race car, which is by no means emissions compliant, can pass this check with the press of a button.
https://en.wikipedia.org/wiki/Volkswagen_emissions_scandal
Emission control is a balance between emissions, fuel economy and performance. You can give up some fuel economy and or performance at test time and enjoy better performance at the rest of the time if the system knows it is being tested.
very hard to detect oxygen around exoplanets apparently but they came up with a new method recently
https://news.ucr.edu/articles/2020/01/06/scientists-develop-...
Oh, sure, it can tell you who smelt it. But the real money is in figuring out who dealt it.