Coffee Cup Calorimetry

Approx 15^oC rise by adding 20g calcium chloride to 50ml water. Similar decrease with 20g ammonium chloride.

Change pdf filesize

This option changes the resolution of the output file in ghostscript.

-dPDFSETTINGS=/screen

So, for example

gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -dPDFSETTINGS=/printer -sOutputFile=output.pdf file1.pdf file2.pdf

Options are:

• screen (72 dpi)
• ebook (150 dpi
• printer (300 dpi)

Batch convert .odt to .pdf

 

lowriter --headless --convert-to pdf *.odt

Export csv from Strava

You can't export csv, but you can get it like this:

Go to your Activities in Strava. It will show you your last 20 activities. Inspect the page (developer tools in browser)

Click "Network", "XHR" and maybe filter for "training"

Make a request in Strava, eg. by choosing type of activity "ride", then you will see it in the inspector. Click Response and you get to see your data in JSON. Copy it into this website: Convert csv, which gives you the csv. If you do that every 20 activities or less, it not that much effort.

From https://scottpdawson.com/export-strava-workout-data/

grep file contents recursively

grep -r -B 2 -A 2 "apt" *

Searches all files from here on down for the string apt, and display two lines before and after each hit. Add -i to ignore case.

parallel ssh with sudo

sshpass -f pw parallel-ssh -i -v -h hostlist -l computer -A -O StrictHostKeyChecking=no -x "-t -t" -I "sudo shutdown -h now" < pw

Record my desktop

Youtube's recommended resolution is 1280x720.

A y-offset of 50 cuts off everything above the browser tabs (with taskbar at top)

so this line is good:

recordmydesktop -y 50 --width=1280 --height=720