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Why do older batteries degrade if set on top of a concrete floor?

Recently, it’s come to our attention that placing a battery directly on concrete can cause the battery to discharge or decay in some sort of way. We were storing some pretty strong batteries on a concrete floor for extended periods of time. The person who told us this information declined to explain why this occurs. […]

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Ask Mathematics

:Find the parameter m so the equation has real solution

Recently, I have found this problem: Find the parameter $m \in \Bbb{R}$ so the equation has real solution $$\cos^2(2x)+3m^2=4m(\cos^4(x)-\sin^4(x))$$ I suppose that the answer is $\forall m \in \Bbb{R}$, but how can we show this? I have tried to factor the right side, obtaining $\cos^2(x)+\sin^2(x)$, but how can we go on?

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User Help

Should I replace my applications’ bundled Python directories with links to a single Python library?

Recently, I reinstalled Python on my Windows 10 PC, and after a minor issue (the installer didn’t automatically add itself to my PATH for some reason, so I had to manually add it myself), I decided, on a whim, to search my filesystem looking for all Python installations. As you might expect, I found many, […]

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Ask English Speaking

An expression to describe ‘holding back on doing something until the last (and completely useless) moment’

Recently, New York Gov. Mario Cuomo pointed out that the US Federal government had 20,000 ventilators in stockpile, but were holding back on distribution until some ill-defined moment of criticality when the critical moment was actually “now”. I have also seen this kind of situation in my own country in the past: emergency supplies donated […]

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User Help

HSM: How multiple users are supported (using SAM)?

So far, I knew that traditional HSMs (Hardware Security Module) can be used to store key of a single user. But, recently, I came to know that newer HSMs have the capability to store keys of multiple users and let users use those keys to sign documents. Newer HSMs does this using Subscriber Authentication Module […]

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Linux Mastering Development

How viable is it to ditch pulseaudio?

Recently, I have been experiencing some audio problems with the pulseaudio server that seem very difficult to resolve, for example see this question. I am increasingly starting to dislike the way it is designed, particularly that way that the root user seems to be heavily restricted from starting/accessing a server, which is affecting my ability […]

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User Help

What is echo doing?

Recently, I noticed that echos in which I include lots of “!” result in weird stuff. For example: echo !! gives me: echo rm -r * 1000 rm -r * 1000 (rm -r * was the last command I executed before typing it). Why is this happening, and is there a way to disable it?

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Linux Mastering Development

How viable is it to ditch pulseaudio?

Recently, I have been experiencing some audio problems with the pulseaudio server that seem very difficult to resolve, for example see this question. I am increasingly starting to dislike the way it is designed, particularly that way that the root user seems to be heavily restricted from starting/accessing a server, which is affecting my ability […]

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Ask Mathematics

Accessibility relation in non-classical logics: hereditary or not?

Recently, I am reading course materials on intuitionistic and modal logics. I have two questions about the notion of accessibility relation in Kripke semantics for intuitionistic and modal logics. When we give a Kripke semantics for intuitionistic propositional logic (IPL), the accessibility relation (usually written as $\leq$) is said to be hereditary: If $w\Vdash p$, […]

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Linux Mastering Development

How Can I Add A Dual-Boot Installation of PrimeOS to my GRUB?

Recently, I installed PrimeOS (Standard version) onto my computer in its own ext4 partition. During the installation it asked if I would like to install GRUB2, obviously unaware that my computer already had it. This attempt to install Prime is only just after a nasty encounter with Android-x86, where a new GRUB was installed without […]