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I’ve gone through too many to list them all here, but I’ve come away with a few points. some have a mysterious approval process and are very hard to be approved by some are unsafe, have predatory or unuseful/uninteresting ads some have unappealing ad formats or very limited ad formats some have no way of […]

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## What happened to my bitcoin? 0 balance

I logged in to my blockchain.com wallet to find my bitcoin are all gone. The log of my bitcoin transactions is also wiped clean. The only thing that is still there is a log of my past ether transactions. When I use the blockchain explorer to search for the two public keys that were used […]

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## Preventing power loss Arduino

We are building a rocket flight computer with Arduino MEGA which will be powered by a 9V Duracell battery. In other forums we asked what to watch out for while building this computer and one of the answers were: Watch out for power failures, batteries might not work properly under high g’s . They suggested […]

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## When we raise a signal to a power n, does the bandwidth always gets multiplied by n?

I know that when we have a message signal $$m(t) = \cos(\omega t)$$ when it gets squared, its bandwidth gets doubled, because $$\cos^2(\omega t) = \frac{1}{2}+\frac{1}{2}\cos(2\omega t)$$ But is this true to every possible signal m(t)? What if I raise it to an arbitrary power n?

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## How to demonstrate mathematically the conditions of reflection in transmission line?

We are all taught about transmission lines and its associates — characteristic impedance, reflection, standing wave, etc. It is well known what happens when a transmission line is terminated with different types of impedances: 1) Open – reflection occurs 2) Shorted – reflection occurs but inverted 3) Equal to Zo – no reflection 4) Between […]

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## I’m building an H bridge and I’m stuck at some point

Here’s the H bridge I’m building Vcc = 9v 10 k resistors for the pullup 1k resistor for the transistor 2 PNP BC557 2 NPN BC547 2 push buttons It should have a DC motor but I’m using LED and a resistor instead for safety purposes. (original) so I’m connecting everything exactly like the sheet, […]

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## render different fields of a content type (media) in a twig templates

For the video media type of drupal 8 i want to render the fields of it into a tag. i created the template field–media–video.html.twig copy of field.html.twig i render the field like this : That is working properly when the display mode that i use to render that video media only contain one field, in […]

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## Sound no longer works after updating Linux Mint and I’ve lost the tray icon: what should I try next?

My sound no longer works… what should I try next? I recently updated Linux Mint (uname -r gives 4.15.0-99-generic) on my Dell laptop, and afterwards I completely lost audio (using the laptop’s built in speakers), along with the tray icon: Using the sound buttons on my keyboard, I’m able to increase/decrease the volume and mute […]

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## How to execute output of File2 lines modified from sed substitutions from File1

File1.txt contains a list of hosts: computer_1 computer_2 File2.txt contains a list of commands… ping host_name -c 10 dig host_name A host_name AAAA +short …to be executed on hosts. Before the commands can be executed, sed -e “s/host_name/$line/”$2 substitutes the host_name string in file2 w/ the actual hostnames from File1. I end up w: […]