|261 forum posts|
My take from all the above interesting discussion - whilst not reading every link - is that perhaps the purpose of the 'special toothpaste' may be to promote the formation of micro-bubbles rather than just bubbles, which then fulfil the function of cavitation and hence cleaning. (what is the pH of this toothpaste ? ) A similar effect, perhaps, to my adding 5ml of dish-washing-liquid in my domestic ultra-sound cleaning tank which apparently lowers the surface tension of the water thus promoting the formation of more numerous, smaller sized bubbles.
|Robin Graham||02/09/2019 01:28:48|
|612 forum posts|
Dave, I thought (before reading MichaelG's credible hypothesis about foaming) that Ruppel's SEM image must be of a solid structure and hydrated silica seemed the best candidate given that it's odd, amorphous stuff. Maybe I should have said 'most' rather than 'only'. Do you see an alternative if the image is of a solid in the toothpaste?
The doggy utrasonic toothpaste is indeed peppermint, which our dogs detest. We also have enzymatic (non-ultrasonic) dog toothpaste which is flavoured with 'poultry extract' - I try not to think too much about that means! Problem is they like it so much that they want to eat the toothbrush.
Sadly I didn't get the opportunity to test the brush on rust today but I did look up ultrasonic derusting in case it was a crazy idea. It seems that it should work - I'll give it a go when I can.
pgk - I reckon you could be onto a winner with your quinoa and goji berry idea. But:
The pet food manufacturer looking for new flavour ideas wasn't keen on my suggestions of Robin with Mouse flavour.
Over my dead body mate.
Edited By Robin Graham on 02/09/2019 01:32:24
Edited By Robin Graham on 02/09/2019 01:37:20
|pgk pgk||02/09/2019 08:25:52|
|1486 forum posts|
The ultimate in recycling?
You're probbaly aware that pelleted dog/cat food is an extruded mix that has the flavour sprayed on at the end of the process. They call that flavour 'digest' and while one hopes it's steam produced and analagous to boiling up a chicken carcase (or whatever) for soup then i guess the best that can be said is that its no worse than a turkey twizzler.
As another light hearted but true comment: we were given trial cans of venison cat-food which was actually god stuff asa novel protein for possible allergy cases. As usual we got sent an awful lot of cans to give away early December. I put a sign up "Feed your cat Rudolf for Christmas"
|mark costello 1||02/09/2019 17:17:00|
548 forum posts
I always thought "mouse in a can" would be a viable idea.
|Michael Gilligan||11/11/2019 20:17:29|
14244 forum posts
Resurrecting this thread:
About 17 minutes into this: **LINK**
The Secret Life of Waves: www.bbc.co.uk/iplayer/episode/b00y5jhx
there is a short piece at University of Southampton, which may be relevant.
|Robin Graham||12/11/2019 23:03:40|
|612 forum posts|
Thanks for that Michael - interesting stuff. Keen as I was I didn't do my 'rust removal with an ultrasonic toothbrush' experiment because on reflection I thought domestic disharmony might ensue. It turned out that dog had a rotten tooth which has now dropped out - whether by nature or with the assistance of ultrasound I don't know. The animal is now chomping happily and the toothbrush has become redundant - it'll find it's way to my workshop I expect. In due course.
|Howard Lewis||14/11/2019 19:53:06|
|2440 forum posts|
Probably throwing the thread somewhat off topic, the implosion of bubbles can be quite damaging, or effective, depending on the context..
The manufacturers of engines with wet cylinder liners had problems with what was called "waterside attack". This caused the cylinder liner to become porous, allowing coolant to make its way into the sump, via the microscopic holes in the liners. The problem was that as the piston reversed direction at top and bottom of the stroke, the skirt slapped the wall. This caused the coolant to cavitate, presumably because of minute deflections of the liner. When the resulting cavitation bubble imploded, it knocked the ferrite out of the liner.
One solution was to move the gudgeon pin off the centreline of the bore, to reduce the slap. Others chromium plated the liners, but ultimately the cavitation still made its way to the liner!
So US should be a good way to clean Fido's teeth, as long as not overdone. Possibly, water would be an effective conveyor of the US pulse, since this basically the main constituent of some US cleaning baths.
Give a product a fancy name and you can sell it for a vastly inflated price.
Or am I a cynic?
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.