Search found 280 matches

by Dan Knapp
Sat Apr 11, 2020 10:43 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

In reading the latest CDC guidelines for critical worker protection, they referred to “Fusion Center employees” as a critical group. I thought it was nice that the government thinks fusion is that critical, until I looked up what a “Fusion Center” is. Fusion Centers are state-owned and operated cent...
by Dan Knapp
Sat Apr 11, 2020 11:44 am
Forum: Vacuum Technology (& FAQs)
Topic: First ever Turbo experience
Replies: 38
Views: 6574

Re: First ever Turbo experience

Turbo controllers often include signal lines for rotational speed readout (commonly 0-10 VDC) as well as a switchable line for reduced speed or “soft start.” I find it useful to be able to switch to reduced speed and read out the rotational speed (yet another use for the red HF freebie meters).
by Dan Knapp
Fri Apr 10, 2020 7:49 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

To fellow junk collectors, on my morning bicycle ride I saw two portable dehumidifiers sitting at the curb. These are a source of small refrigeration systems that could be used for cold traps on diffusion pumps or for drying deuterium. In my earlier life we used such small refrigeration systems with...
by Dan Knapp
Thu Apr 09, 2020 2:07 am
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

I thought the group might be interested to know that “wastewater epidemiology” is beginning to take off in the US as a method to assess the spread of the virus in the population. A group from MIT/Harvard just posted a paper (https://www.medrxiv.org/content/10.1101/2020.04.05.20051540v1.full.pdf) whe...
by Dan Knapp
Sun Apr 05, 2020 10:52 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

The mask was made from material I cut from a tee shirt I picked up at a physics meeting years ago. The remainder of the tee shirt didn’t say who was giving them away.
by Dan Knapp
Sun Apr 05, 2020 7:54 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Fusor V construction - the process long running
Replies: 44
Views: 5811

Re: Fusor V construction - the process long running

If you need a way to make really sharp tungsten tips, I suggest using the electrochemical etching method used to make scanning tunneling microscopy probes. I used this approach when I tried to make a sharp focus cold cathode electron source. I wasn't able to get the electron current I was seeking, b...
by Dan Knapp
Sun Apr 05, 2020 4:49 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

72B2E5E3-2E25-439C-A4EF-80829DA689FD.jpeg
72B2E5E3-2E25-439C-A4EF-80829DA689FD.jpeg (30.47 KiB) Viewed 812 times
If you’ve been wondering what to do with that box of old tee shirts you picked up at meetings and trade shows over the years......
by Dan Knapp
Sat Apr 04, 2020 3:22 am
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

Sewage epidemiology has suddenly become a hot topic. This story just came out today in Nature: https://www.nature.com/articles/d41586-020-00973-x?fbclid=IwAR0ZPLGPICcxmi1-TGI8zd4S3ozNyvcmwuOnPcYI75RgcGDEmdFVjBZqwYA They say measuring virus in sewage could be key to early warning of a second wave of ...
by Dan Knapp
Wed Apr 01, 2020 9:08 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

We all have it.
by Dan Knapp
Tue Mar 31, 2020 4:52 pm
Forum: Announcements and Site Administration Topics
Topic: Coronavirus pandemic
Replies: 100
Views: 9883

Re: Coronavirus pandemic

Members of this forum, whom I regard as a group of amateur experimental physicists, will enjoy this quote from John Clauser, “To be an experimental physicist, you need to be able to make anything. You need a mill and a lathe. But, most of all, to be an experimental physicist, you need a junkyard.” (...