The correction was "decimated" literally means "decreased by 10%".
If you meant a 90% decrease you should have said.
Your link shows transportation in the USofA uses 67% .. that is not 90%, not in the USofA and not globally. Even so the linked article I posted talks of Electric Vehicle use increasing resource demand as more EV cars are built between now and 2050.
EV cars are not the full total of "Transportation" (in the USofA or indeed elsewhere) - a large chunk of that Transportation goes to mining equipment used to estract resources, the use of which will increase to meet resource demand created by EV growth.
With climate change increasing global unrest and decreasing security there will be greater military demand for fossil fuel reserves and use globally - I understand the use of batteries et al in the military and the cold fact that the energy density of fossil fuels is unrivalled.
I appreciate your enthusiasm, your word use and arguments could use some work.
Meh, I was a smart-alec kid there with my friend. The salesperson had to go get a sim card "for the LTE to work" and I said "oh right, because LTE is GSM and requires a sim". The salesman insisted Sprint didn't use GSM so I looked up the wikipedia page for LTE on one of their demo phones and started reading out loud "In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards."
I took it not so much that the increased thought leads to more useful phrases, but that people are more likely to exert this effort toward things they think are useful, rather than lies.
You are going to remember "righty-tighty, lefty-loosey" better than "blue shoe, red bed" because you think it more useful. And you are vastly more likely to put effort into teaching the former to others.
When designing rhymes less for your own benefit and more for others, like advertising slogans, this obviously doesn't hold as well.
> Shouldn't it timeout only when the server is no longer ACK-ing packets?
That's exactly what happens. The server ACKs data until it fills its write buffer, and then stalls unresponsive until the entire buffer is flushed to disk. If it takes longer to flush the buffer to disk than the client's timeout, it gives up.
I have personally watched this happen via wireshark where the server doesn't ACK for more than 10 minutes.
That's not it. I only had this problem on a fast-ethernet connection (because I had to share the cable for two connections). The server could write ~ 50 MB/s, but it still timed out on the 10MB/s upload.
It's possible you were seeing another problem, but this issue is more likely to appear with a faster network connection, because the network transfer happens faster than the disk writes.
You can confirm by watching /proc/meminfo and watching the Dirty and Writeback numbers.
Changing up the vm.dirty* settings can help as described here:
Holy shit i think you and the above comment, along with this thread, may have finally given me the answer to one of the few problems i was never able to solve.
About 4-5 years ago, i was working on a project, and part of that was copying big amounts of data to a system via nfs. At 30 minutes exactly, nfs would croak, transfer fails.
I think this buffer fill and empty flow was fucking killing it. Its a shame i dont work there anymore, id definitely wanna try tweaking these settings and see if i could solve it
Yeah that does sound like the symptoms of the problem I discovered. If you ever witness it again, the trick is watching /proc/meminfo for the Dirty and Writeback numbers.
I am failing to persuade my brother of this. If someone desperately wants to live in a single-family home an hour away from the city center, they should want the city to be nice and dense and lots of cheap housing with great transit, because that will also make their dream home cheaper!
That’s just a pressure differential, and not what the OP meant by ‘negative pressure’. 100% of the lift force on a wing is attributable to the pressure differential across it, after all.
They (or their stackexchange source at least) are - like the referenced article and as is commonly done in aero engineering - subtracting out ambient pressure as a reference pressure, and then viewing pressure above the wing as ‘negative’ and pressure below as ‘positive’. It’s a convenient choice to make, for various reasons, but it is essentially an arbitrary one.
The problem comes when you then go on, like OP did, to come across statements like “how much lift is coming from the negative pressure - about a half”
Now, since in analyzing the pressure we have subtracted the reference pressure and made a zero point in between the low pressure value above the wing and the high pressure value below it, it actually shouldn’t surprise us at all that ‘about half’ of the lift seems to be attributed to the positive pressure below the wing, and half to the negative pressure above the wing.
This is just saying that half the lift on the wing is attributable to the first half of the pressure differential across the wing, and about half the lift attributable to the other half.
One of the problems of using a relative pressure and thinking about negative air pressure is that it gives the impression that negative air pressure, like positive air pressure, can grow arbitrarily large. It can’t. You can’t have a negative air pressure lower than negative ambient air pressure, because the absolute air pressure cannot go below zero.
But what you’re talking about is a relative pressure differential. We can have an arbitrarily large negative pressure differential because we can have an arbitrarily high pressure on one side of it.
It's not arbitrary: negative gauge pressure above the wing means that (by definition) there is a pressure gradient increasing away from the wing (because the absolute pressure far from the wing is ambient pressure), so the net force on the air there is downward.
> made a zero point between ... shouldn't surprise us
Whether or not you are surprised is immaterial, but it is not guaranteed a priori -- you could get a net upward force with ambient pressure above the wing and positive pressure below or with ambient pressure below the wing and negative pressure above (meaning gauge pressure, relative to the ambient pressure distant from the wing, to be clear). The person who started this thread seemed to be implying that the former was a good mental model, and the person you replied to was just saying that in fact for practical wing designs it is somewhere in between.
FWIW it is very common to talk about positive and negative gauge pressure. Some people may say that without understanding what is going on, but it is a mistake to assume that they don't understand just because they use that language.
