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Originally Posted by AsCeNsIoN Why doesn't the super glue stick to the inside of the tube? |
Q: Why doesn't superglue stick to the inside of its tube?
A: Superglue will not stick to the inside of its tube because the tube contains oxygen in the form of air but excludes water. Oxygen inhibits whereas water catalyses.
A: Superglue doesn't stick to the inside of the tube because, being based on a cyano-acrylate monomer, it requires moisture in the form of water or some other active hydrogen-bearing compound to polymerise.
This explains why the best join between two surfaces is made using a thin glue line. An excess thickness of glue will lead to a retarded cure. This moisture sensitivity explains two things. First, why the bottle comes with a seal that's impossible to break without covering oneself in glue and why the resulting spillage adheres so well to your skin - being warm and moist, skin makes an ideal substrate.
A: The Loctite company in the US discovered the inhibition by oxygen of the otherwise rapid polymerisation of cyano-acrylate. That is why the bottle must always be left with plenty of air inside. The liquid monomer converts to solid polymer when oxygen is excluded by trapping it between close-fitting surfaces.
http://www.newscientist.com/article/mg14820087.800.html Quote:
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Originally Posted by AsCeNsIoN Do penguins have knees? |
Do penguins have knees?
1. Yes, though they face rearward, as most birds' knees do. The knees just aren't visible under their feathers.
2. You can see in this picture :
http://www.skullsunlimited.com/black...d_penguin.html that they do have knees very close to their body.
3. Penguins, in common with all birds, have a different arrangement of joints in the legs from those in mammals. However, they do have joints equivalent to our knees - the difference is that these joints are much closer to the hip than on mammals
http://www.answerbag.com/c_view.php/2380#q_12376
Also, the person that wrote the book "Do Penguins Have Knees?" states this:
Penguins DO have knees, and I can prove it. I touched a penguin's knee myself during the photo shoot for this book.
http://www.imponderables.com/do_penguins_have.php