Questions tagged [diffusion]
For questions referring to the process by which molecules move as a result of their kinetic energy.
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How Do Turing's Reaction-Diffusion Models in "The Chemical Basis of Morphogenesis" Relate to Organic and Physical Chemistry?
I'm reading Alan Turing's "The Chemical Basis of Morphogenesis" and its reaction-diffusion models:
https://www.dna.caltech.edu/courses/cs191/paperscs191/turing.pdf
As far as I understand ...
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Convection or Advection term in the Absolute flux of a chemical species
I am confused as I have been reading on mass transport on multiple sources and they seem to use "advection" and "convection" interchangeably in the equation for the absolute flux ...
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Could the presence of multiple stabilizer oxides induce sluggish diffusion in a stabilized zirconia to increase lifetime?
The presence of yttria stabilizes zirconia's high temperature allotropes, but it also decreases the lifetime due to more defects that can induce more diffusion into yttria rich and poor regions, ...
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Graham's Law for mixtures?
If we have a mixture of (ideal) gases, what is the rate of diffusion of the total mixture? Also, what are the rates of diffusion of the individual components?
My teacher said it was inversely ...
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In steady state diffusion of atoms, does dJ/dt = 0 hold true?
My textbook says that under steady state flow the flux is independent of time and remains the same at any cross-sectional plane along the diffusion direction. Further, it gives the following ...
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Smell of orange peel travels super fast
Many years ago, my college chemistry teacher squeezed an orange peel in the front of the auditorium asking us to raise our hands when we smelled it. Hands rippled through the auditorium (at least 40 ...
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Would microelectrodes reach a steady state current if convection is negligible and only pure diffusion occurs?
Assuming a two dimensional Cottrell type problem with a micro-electrode and a high enough applied potential so that concentration of the consumed redox species would be zero near the surface. ...
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How do I express concentration of a substance at the interface between two membranes of different diffusivities and lengths at steady state?
I am lost on this question from my textbook:
"A solute diffuses across two membranes, A and B. The membranes' thickness are $\Delta x_A$ and $\Delta x_B$ respectively. The membranes' ...
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If gaseous oxygen and dissolved oxygen (in water) have the same partial pressure, will they diffuse into solid materials at comparable rate?
To be specific, I am wondering about the dynamics of molecular oxygen diffusion into gas-permeable polymer materials, which is the sensing process of the optical oxygen probe (polymer-encapsulated ...
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Colour composition of Bromine during diffusion?
Consider the diffusion of Bromine Gas within a tube filled with air.
After a prolonged period of time, is the colour composition uniform?
From my understanding, Bromine is a denser gas. Hence, on ...
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What determines how easily a gas can diffuse into a crystal structure?
I have been told by a metallurgist that the reason a factory oxidizes the iron oxides in ilmenite before reducing them down to pure iron, is that the the products of this have a more spacious crystal ...
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How does stirring demonstrate a diffusion-controlled reaction?
I was reading about diffusion-controlled reactions, and on the Wikipedia page (Diffusion-controlled_reaction) it says the following:
"One classical test for diffusion control is to observe ...
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Redefine a Mixing Modulus based on new reaction scheme
I am studying the effect of diffusion on liquid chemical reactions. The model is very simple in that it assumes that striations or slabs of fixed thickness of one reactant are next to the other. ...
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What happens to a solute's potential energy during diffusion?
I was thinking, if you have a large amount of water, with an uneven solute concentration, diffusion will lead to an even concentration of solute throughout the solution.
Intuitively,that would mean ...
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Diffusion rate of drugs - Ficks model?
I have a question about diffusion rate of a slow release drug. The drug I've been taking has an extended-release formulation and contains beads encapsulated in a capsule.
The beads are coated with a ...
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