Great study & article. Perhaps incense is not the most scientific test, but it's effective enough for this setup.
Does anyone know if there is raspberry pi add-on or device that acts as an "air quality" sensor, or similar? It would be interesting to monitor this a bit more scientifically in real-time in a variety of environments.
Lastly, I think I've seen this here before, or on reddit. I was inspired to do something similar myself - I use a 19" box fan and a purple 3M MERV furnace filter, 20" square. Except the rounded corners they are almost exactly the same size. Some white duct tape around the edges to seal/hold in place. Total cost is about $40 usd for the fan & filter. I would anticipate a similar performance to the leaky MERV's, as mine is filtering more air as a ratio to total air flowed by the fan.
Yes, just set up a sensor with home assistant (HA). Incredibly easy. Raspberry pi runs the HA server. The air quality sensor is attached to an ESP32 running ESPHome: https://esphome.io/#air-quality
Almost plug and play. Compiles the FW, flashes it, and the device auto connects to the network and is ready for integration into HA. I used the HM3301 air quality sensor FWIW. You can see my filter here: https://news.ycombinator.com/item?id=28395232
I have bought a few System76 laptops, though not this variant - I like to buy the ones that ship with coreboot.
As for the price difference: you can buy the base model of the System76 and upgrade ram/disk yourself. This is harder to do on the Lenovo ones; it seems the T14 has (some of) the ram soldered on (ugh).
But, it is nice to see that you can actually buy a T14 with Ubuntu preinstalled (if you are willing to wait 4+ months...), and they list it next to the (more expensive!) Windows version:
I've heard this several times about ham radio, and to me as an outsider the idea of shared access to the medium is a bit off-putting to me.
Is it possible to have two-way links "in the clear" but otherwise encoded or ciphered? Is there a regulation that says all transmissions must be in English, for example, or can I transmit in Esperanto/Navajo/hex?
You can speak whatever language you want on the air so long as you identify every ten minutes and at the end of your transmission. The ITU regulations for radio call signs cover their format however and use the Latin alphabet. Call books are also public so anyone can look up the stations and know who you are.
Speaking in shorthand to be clear and concise over the radio is fine. Even using terms of art or abbreviations is likely fine. If you're explicitly coding your communication to obfuscate its meaning you're definitely going to run afoul on the ban of encryption.
Part of the reason for no encryption on ham bands is there's precious little bandwidth available and unintelligible signals (intentionally obfuscated) are tantamount to interference. As a listener I can't reasonably tell if an encrypted signal is noise or a genuine call. I also can't reasonably receive a call sign so I can't know who is transmitting.
> This is without prejudice to the possibility for member states to lift the temporary restriction on non-essential travel to the EU for fully vaccinated travellers.
I already have a trip planned to a Shengen country, planned months in advance. Everything is already paid for. I am also vaccinated fully (with certificate). Am I going to be allowed on my vacation next week?
Short answer is: yes. Just remember to fill the Passenger Locator Form [0]. You may fill any time before getting to the boarding area, where they will ask to see that and your vaccination card or a negative test obtained within 48 hours. Technically is 72 hours, but airlines are stricter.
It will take a minute before the single EU countries will adopt regulations following the the recommendation.
That being said any country can implement any restrictions at their discretion, and you might not be allowed in hotels, for instance (although that was implemented mostly during harsher spikes).
Golang backend, some light vanilla Javascript frontend. postgres db. running on podman (docker-compose), fedora server.
I have some background in C programming, so Go was easy to pick up. the standard libs are great for building server-side webapps with a sql backend. templates lib and some glue javascript make front-end pages a breeze.
I'm a linux guy thru-and-thru, so running fedora server on the latest kernel. latest podman from RedHat and docker-compose to orchestrate.
I'm one guy so I don't do any HA or cloud or any other funny business. My one server is racked nearby and I've had good history with the colo.
I already use Fedora Workstation and am familiar with the environment, install, and setup process. CoreOS' "happy path" seems to be cloud (or at least hosted in a hypervisor) -native, and that was not the target here. There seem to be external dependencies on installing it to bare metal I didn't want to mess with[1]. I installed Fedora Server from .iso almost exactly the same way I've installed Fedora (workstation) many times.
My "day job" uses rhel, and with the recent CentOS end-of-life debacle I'd like to stay both FOSS and .rpm-compatible with rhel. I don't know for sure, but I think CoreOS is a different "vertical" than the fedora/rhel/centOS family.
I'm generally wary and suspicious of "automatic" updates, preferring to control when/how updates are applied to my machines. $ sudo dnf system-upgrade is a well-known quantity to me.
I have a complicated LVM setup, and significant time/effort already invested into LVM. As of F34 LVM/ext4 is still first-class.
CoreOS seems to be targeting cloud/kubernetes as implementation characteristics, and my "one man shop" gig is the anti-that. I'm pretty old school - only just started learning Docker about a year ago. I've recently bought into containers as packaging/deployment aids, and using docker-compose to keep deployment in version control. I guess all of this is to say I'm trying to "keep it simple / stupid" and re-use what I already know. Unless CoreOS can give me order-of-magnitude performance gains, I don't know the value prop beats the cost to pick it up.
| If CentOS Stream is going to be just a FOSS upstream for RHEL, will you still pick Fedora Server over it?
Yes, but only because Fedora Server is (also/even more) a FOSS upstream for RHEL. Doing something that isn't Fedora (Workstation/Server) is "one more thing", however small, and I'd rather spend the brain tokens elsewhere. If it 10x'ed my app I'd do it, but I can't imagine it would.
Thanks for the links, I wasn't so mad at CentOS Stream the product itself per se, I think it's a valid product / change to the old model. My biggest issue is the changing of the promises - the supported life of the product changed in-production. That's a big no-no to me.
Fedora (upstream) requires you to keep up, but at least it doesn't make promises that it won't keep.
I have been using Fedora Workstation for a while now, and I am trying to pick the best single-server OS for all my future projects.
Since Fedora is now a direct upstream for CentOS Stream – and CentOS Stream 9 is basically a LTS version of Fedora 34[1] – I am leaning towards CentOS Stream.
In fact, CentOS Stream might now even make sense as a stable desktop OS, and as a better alternative to Ubuntu LTS.
I suspect that at least part of the reason that it's not as effective as expected is that the current US RDA is over an order of magnitude too low, due ancient arithmetic error we discovered in 2014:
9k is what the science suggests, if you correct for this error, though, given that vitamin D absorption is highly variable, it's best to have your levels tested repeatedly until you know how much you need to take. (I am currently taking 15k daily, and only recently got my levels to stop bouncing around the bottom end of normal.)
IMHO, this huge discrepancy between our previous understanding and the actually needed amount is also likely why so much vitamin D science is often conflicted: the differences between supplementing 2k iu (a number I've seen a bunch of times in the literature) and not supplementing aren't all that great if you needed 9k to begin with.
I should also mention that concerns about vitamin d overdose are also misguided: while serious, it takes heroic doses on a daily basis - for years:
The evidence is clear that vitamin D toxicity is one of the rarest medical conditions and is typically due to intentional or inadvertent intake of extremely high doses of vitamin D (usually in the range of 50,000-100,000 IU/d for months to years)
Addtionaly, one may want to be conscious of one's magnesium intake as well: it is consumed during vitamin d metabolism, and our widespread misunderstanding of vitamin D requirements means that research into appropriate magnesium intake concurrent to increased (ie appropriate) vitamin D has not been done.
just stick with emacs defaults, or if you already know vim use doom or evil mode.
emacs' modes give you syntax highlighting, formatting, code completion, a repl, and more. I do a lot of python work (not too much C), and still prefer emacs+python over vscode, idle, others.
Aha - that's what this is. I keep wondering why many sub-20$ items on eBay keep getting cancelled on me. The equivalent item on Amazon is usually 20-25$ (but doesn't quality for free tier shipping on its own) so I shop eBay for same - half the time or more recently it's either a) a drop-ship from Amazon even in its box/packaging, or b) cancelled as 'buyer requested cancel'. I knew it was a scam but I didn't know what for.
Good thing I ship to a PO box and use a generic C/O name.
Does anyone know if there is raspberry pi add-on or device that acts as an "air quality" sensor, or similar? It would be interesting to monitor this a bit more scientifically in real-time in a variety of environments.
Lastly, I think I've seen this here before, or on reddit. I was inspired to do something similar myself - I use a 19" box fan and a purple 3M MERV furnace filter, 20" square. Except the rounded corners they are almost exactly the same size. Some white duct tape around the edges to seal/hold in place. Total cost is about $40 usd for the fan & filter. I would anticipate a similar performance to the leaky MERV's, as mine is filtering more air as a ratio to total air flowed by the fan.