Thermal effects at nanoscale

Question 1

How is the diffusion constant defined?

Answer 1

D = L^2/2 time_step
L - step length
N = t/ time_step

Question 2

What is the damping coefficient?

Answer 2

2m/ time_step

Question 3

Explain the Reynolds number.

Answer 3

dimensionless. an indication of how relevant the inertial component wrt to the viscous component is when a fluid moves wrt to a surface.

Question 4

What does the Boltzmann distribution tell us about the probability of finding a particle at r under thermal excitation?

Answer 4

p(r) = p_0 exp (-U(r)/kT)

Question 5

State Archimedes Principle.

Answer 5

A body immersed in fluid is buoyed up by a force equal to the weight of fluid displaced.

Question 6

During metal nanoparticles synthesis, nano-clusters stabilise at specific sizes. Explain the reason behind these stable sizes.

Answer 6

magic numbers of closed shells where particle energy reaches a local minimum.