Kari Dalnoki-Veress (he/him)
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Kari Dalnoki-Veress (he/him)
@kdalnokiveress.bsky.social
340 followers 430 following 20 posts
Soft-matter physicist @ McMaster University; cofounder @ MesoMat
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kdalnokiveress.bsky.social
Columbia is an embarrassment. When the strong surrender, hope dims for all.
July 24, 2025 at 1:20 AM
kdalnokiveress.bsky.social
On the left the effective buoyancy is not large enough to separate the chain, but as the chamber is tilted, the force balance shifts in favour of the effective buoyancy and eventually the chain snaps (right).
Optical microscopy images of the experiment. On the left, 5 oil droplets, about 50 microns in diameter, in a straight chain. One of the droplets at the top is held by the hopper-like constriction. There are two force arrows. Adhesion (up) is bigger than effective buoyancy (down) On the right, the same image, but now the effective buoyancy is larger than the adhesion arrow (because the tilt is grater) and the bottom four droplets have sepparated from the top imobilised droplet
December 17, 2024 at 4:56 PM
kdalnokiveress.bsky.social
Fun paper by Johnathan Hoggarth, where we use some very simple first year physics to measure the adhesion between particles. This will appear in EPJE as a Tips&Tricks paper.
arxiv.org/abs/2412.11311
schematic of an experimental chamber. Two glass slides from the top and bottom of a reservoir with an aqueous liquid. Within that liquid are small oil droplets (in yellow). There are 4 droplets that form a chain, of which one is held fixed within a hopper. The chamber is tilted, and since the droplets are buoyant, the chain forms a dangling bunch of droplets which are tethered to the one droplet that is imobilised by the hopper. The tilt angle is theta. The idea is that as the tilt increases, the effect due to buoyancy increases, and eventually the three droplets detach from the imobilised droplet.
December 17, 2024 at 4:56 PM