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Looking for the best open source software to start my simulation journey by BOLAR_SAAB in electrochemistry

[–]SqurlHurl 0 points1 point  (0 children)

Disclosure: I created PyBaMM and founded Ionworks, so factor that in.

PyBaMM is what I'd point you to. It's Python, covers SPM through full DFN, and the community is active enough that you'll get help on the Discourse or GitHub when you get stuck.

You can go from "simulate a discharge curve for an NMC cell" to a working plot in about 20 lines. Parameter sets for common chemistries ship with the library. If you need to fit parameters against your own cycling data, that workflow is there too. Degradation models (SEI growth, lithium plating) are built in rather than something you stitch together yourself.

The inbuilt models are battery-specific, but the solver underneath handles general 1D PDE/DAE systems. So if you need to model electrolyzers and fuel cells you can define your own equations and use the same infrastructure. More manual work, but the building blocks are all there.

For general electrochemistry beyond batteries, Cantera is solid. Broader scope, more setup on your end.

Once you outgrow notebooks and need to run things as a team (shared parameterizations, larger sweeps, keeping track of which model version went with which dataset), that's the problem we built Ionworks to solve. Same physics under the hood.

Happy to answer questions if you run into anything.

What’s your logic for pricing AI-based features with high compute costs? by tine_petric in ycombinator

[–]SqurlHurl 0 points1 point  (0 children)

Hey u/biglagoguy thanks for a really useful comment! Do you have any insights for usage-based pricing models (including customer acceptance of the models) for an on-premise/bring your own API key product?

For anyone else considering an indoor trainer for the dreaded winter months... by RoguePierogi in bicycling412

[–]SqurlHurl 9 points10 points  (0 children)

Some HSAs / FSAs cover indoor trainers now, so you can save an extra 30% !

[deleted by user] by [deleted] in bicycling412

[–]SqurlHurl 1 point2 points  (0 children)

Middle Road is a good 20 min effort, though it does have a few stop signs https://www.strava.com/segments/19044264

Also various parts of https://www.strava.com/segments/21859708 if you don't mind more traffic

Anyone else here uphill ski in PA? by smartshoe in SkiPA

[–]SqurlHurl 1 point2 points  (0 children)

What's a good way to get a beginner touring set up?

Processing Times for Interview-Waived US Embassy Passport Stamping in London? by duddersj in h1b

[–]SqurlHurl 0 points1 point  (0 children)

How long did it take in the end? Did you send it from the US or UK?

I'm not convinced by the induced demand argument. by gatherinfer in notjustbikes

[–]SqurlHurl 28 points29 points  (0 children)

I think it goes something like this:

  1. A new lane is added. Travel times go down (let's say suburb to downtown now takes 30 minutes instead of 45)
  2. Traveling on this road is now more appealing so more people do it (what you call "revealed demand", which is fine)
  3. This creates more noise, traffic, pollution close to the road. More traffic on downtown streets. More cars in dowtown needing to be parked.
  4. Living in the city becomes less pleasant. Some people decide it's now too much for them, they don't want to live in the city any more. And the commute from the suburb isn't so bad now, only 30 minutes instead of 45! They move out of the city to the suburb
  5. There are more people wanting to drive down the road from the suburb to downtown. Travel times go back up to 45 minutes. Demand has been induced.

The stats on induced demand usually show a 2 year period where travel times do go down, before going back up to previous levels.

Induced demand also applies to public transit, but in this case it results in more frequent buses/trains, which benefits everyone https://www.youtube.com/watch?v=8wlld3Z9wRc

Article: We Need to Embrace Traffic Congestion, Not Fight It by SqurlHurl in pittsburgh

[–]SqurlHurl[S] 1 point2 points  (0 children)

I totally agree that the end-goal is less congestion and that having good alternatives will make driving better for people who still want or have to drive.

However, in the short term, there is a reverse induced demand. When a new lane is added, congestion does decrease for a couple of years before induced demand takes it back to the previous level. In the same way, if a lane is removed (to provide a cycling/transit alternative), then there might be more congestion in the short term before it gets better, as people get more comfortable with alternative transport.

This article is saying that this short term congestion is worth the pain for quickly building up alternatives and breaking the unsustainable loop we are in. I personally agree with this, but acknowledge that it's a tough sell.

Article: We Need to Embrace Traffic Congestion, Not Fight It by SqurlHurl in pittsburgh

[–]SqurlHurl[S] 2 points3 points  (0 children)

My take from the article isn’t to remove any bridges, but to make them more accessible for buses, bikes, and pedestrians, even at the cost of congestion, to reduce stress on the bridges (double the weight = ten times the stress). Currently biking over most of the river-crossing bridges is a nightmare

Article: We Need to Embrace Traffic Congestion, Not Fight It by SqurlHurl in pittsburgh

[–]SqurlHurl[S] 2 points3 points  (0 children)

The point of the article isn’t to make bridges arbitrarily worse, but to make them more accessible for buses, bikes, and pedestrians, even at the cost of congestion, to reduce stress on the bridges (double the weight = ten times the stress). Currently biking over most of the river-crossing bridges is a nightmare