5,388 research outputs found
Controlling the Size of Popcorn
We present a thermo-statistical model of popcorn production and propose a way
to control the final size of the popcorn by monitoring only the chamber
pressure.Comment: 6 pages; revision (typo and minor content corrections
Density Functional Theory of Hard Sphere Condensation Under Gravity
The onset of condensation of hard spheres in a gravitational field is studied
using density functional theory. In particular, we find that the local density
approximation yields results identical to those obtained previously using the
kinetic theory [Physica A 271, 192, (1999)], and a weighted density functional
theory gives qualitatively similar results, namely, that the temperature at
which condensation begins at the bottom scales linearly with weight, diameter,
and number of layers of particles.Comment: 17 pages, 4 figure
Increasing the Size of a Piece of Popcorn
Popcorn is an extremely popular snack food in the world today. Thermodynamics
can be used to analyze how popcorn is produced. By treating the popping
mechanism of the corn as a thermodynamic expansion, a method of increasing the
volume or size of a kernel of popcorn can be studied. By lowering the pressure
surrounding the unpopped kernel, one can use a thermodynamic argument to show
that the expanded volume of the kernel when it pops must increase. In this
project, a variety of experiments are run to test the validity of this theory.
The results show that there is a significant increase in the average kernel
size when the pressure of the surroundings is reduced.Comment: Latex document, 14 pages, 4 figures, 1 page of table
Measurement of Isothermal Pressure of Lattice Gas by Random Walk
We present a computational random walk method of measuring the isothermal
pressure of the lattice gas with and without the excluded volume interaction.
The method is based on the discretization of the exact thermodynamic relation
for the pressure. The simulation results are in excellent agreement with the
theoretical predictions.Comment: 10 Pages, 2 Figures, Teaching Material. To Appear in Physica
Condensation of Hard Spheres Under Gravity
Starting from Enskog equation of hard spheres of mass m and diameter D under
the gravity g, we first derive the exact equation of motion for the equilibrium
density profile at a temperature T and examine its solutions via the gradient
expansion. The solutions exist only when \beta\mu \le \mu_o \approx 21.756 in 2
dimensions and \mu_o\approx 15.299 in 3 dimensions, where \mu is the
dimensionless initial layer thickness and \beta=mgD/T. When this inequality
breaks down, a fraction of particles condense from the bottom up to the Fermi
surface.Comment: 9 pages, one figur
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