Wikipedia:Reference desk/Archives/Science/2021 October 2

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October 2

Volumes of non-ideal solutions and thermodynamic activity

How can densities data of non-ideal solutions at various temperatures (and perhaps even various pressures) be used to determine the thermodynamic activity coefficients, considering the relations involving partial derivatives of the activity coefficients like

${\bar {V}}_{i}^{\mathsf {E}}=RT{\frac {\partial }{\partial P}}\ln(\gamma _{i})$ (excess partial molar volumes)

obtained from the relation of the activity coefficient to the excess partial molar Gibbs energy

${\bar {G}}_{i}^{\mathsf {E}}=RT\ln \gamma _{i}$?--178.138.98.154 (talk) 00:59, 2 October 2021 (UTC)

Wow no responses yet? I'd ask at Reddit ChemPros and Chemistry StackExchange. The 2nd has lots of PhD candidates there. 67.165.185.178 (talk) 02:48, 6 October 2021 (UTC).

Washed out colors in videos on Ryzen 7 5700U

I bought a Lenovo Flex 5 15.6" 2-in-1. Nice images. I was starting to enthuse about the machine, even if it's a bit large, although large has its own benefits, but then I went to utube. Videos looked distractingly washed out in places, in what I assume to be the motion blur that some reviews complain about on a similarly-specced Yoga model. Given the same manufacturer, I assume the problem has the same cause.

I find it hard to believe that in 2021, spending over $700 on a laptop, I would have trouble watching the simplest videos. Is this normal? What's causing it? Thank you. Imagine Reason (talk) 03:22, 2 October 2021 (UTC)

I'm not sure what Yoga problem you're referring to as you provided no links but motion blur or ghosting does not sound like the same problem as washed out colours to me. Both could be because of a poor or defective panel but again in different areas. Especially for video playback it's also unlikely either have anything to do with the GPU or CPU or really any other parts of the hardware i.e. the only thing that likely matters is the panel not how well specced the other hardware is. However washed out colours could much easily be some undesirable setting in your settings especially colour, contrast or brightness including any video enhancements options so check your settings including in your GPU drivers. Note that for laptops, given the way they are normally used, may still have panels with poor viewing angles so it may matter a great deal if your watching straight on, or from the side (including the top or bottom) Nil Einne (talk) 04:04, 2 October 2021 (UTC)

Before you conclude it's specific to your machine, maybe you could provide an example link? ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:35, 2 October 2021 (UTC)

Sounds like a driver issue. I'd suggest going to Lenovo's support site and downloading the newest graphics driver for your OS. Windows in particular often doesn't come with newest drivers out of the box. 93.136.33.168 (talk) 19:41, 4 October 2021 (UTC)

What does a changing magnetic field mean?

By definition, electromagnetic Induction is a current produced because of voltage production (electromotive force) due to a changing magnetic field.

If I take a bar magnet and spin at high speed so that magnetic field will change. Will it give me current according to this above definition? Rizosome (talk) 07:41, 2 October 2021 (UTC)

You need an electrically conductive circuit for a current to run. The spinning magnet and electrical circuit together form a primitive electric generator.  --Lambiam 08:28, 2 October 2021 (UTC)

Chances Hawaii will be destroyed by volcano?

As I understand it, some of Hawaiian islands are older than others, so they're further away from the most likely eruption spots. Are they relatively free from the likelihood of being destroyed by a super eruption? Are the newest islands in appreciable danger of being covered by a big eruption, or is the nature of the volcano island less dangerous? What about a tsunami? 74.64.73.24 (talk) 15:19, 2 October 2021 (UTC)

It appears that the Hawaiian islands are mostly Shield volcanos, which are not typically explosive like a Stratovolcano. But never say never. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:41, 2 October 2021 (UTC)

See here. Count Iblis (talk) 18:12, 2 October 2021 (UTC)

Nice. The more you know... 74.64.73.24 (talk) 02:35, 3 October 2021 (UTC)

See evolution of Hawaiian volcanoes and the Hilina Slump. There is also significant earthquake risk, see the 1868 Hawaii earthquake. Mikenorton (talk) 10:09, 4 October 2021 (UTC)