Data for Tapia-Ignacio, Phys Rev E (2020)

Data from experiments studying the motion of ellipsoidal particles lying on top of a magnetically excited granular layer. Data taken at Univ. Autonoma del Estado de Hidalgo.

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Experimental data: ellipsoidal particles on granular layer

These data sets were studied in:

"Brownian motion of ellipsoidal particles on a granular magnetic bath"
C Tapia-Ignacio, RE Moctezuma, F Donado, & ER Weeks, Phys. Rev. E 102, 022902 (2020).
- Abstract / PDF / journal / arXiv:1910.05887v2

Animated GIF movie: click image to play. This is from the "5p5" data for which the granular magnetic bath particles are most active. This is for the alpha = 2.20 floating ellipse particle.

Raw data: bath particles (Fig. 4)

The data are in the format (x,y,frame number,ID). The coordinates x and y are in units of mm. The data are taken at 60 frames/s (that is, to convert to seconds, multiple time by 1/60). These are the data analyzed for Fig. 4 (MSD of bath particles). Note that the naming convention is universal across all the files on this webpage: the filenames contain designations like "3p0" that indicate the magnetic forcing (36 G for 3p0). Originally, 3p0 stood for 3.0 (three point zero = 3p0) which was the AC voltage used for the Helmholtz coils.

bath2p5.zip -- Bo = 30 G data (lowest forcing)
bath3p0.zip -- Bo = 36 G data
bath3p5.zip -- Bo = 42 G data
bath4p0.zip -- Bo = 48 G data
bath4p5.zip -- Bo = 54 G data
bath5p0.zip -- Bo = 60 G data
bath5p5.zip -- Bo = 66 G data (highest forcing)

Raw data: size-varying experiments (Fig. 3)

size.zip: The data are in the format (x,y,theta,frame number,ID). The coordinates x and y are in units of mm, and theta is in degrees. The data are taken at 60 frames/s (that is, to convert to seconds, multiple time by 1/60). These are the data analyzed for Fig. 3 (diffusion constants for different sized floating particles). The files are labeled a-j depending on the mass of the floating particle, and circ or ell for the circular and ellipse particles. The masses are given in this table:

name	circle mass	ellipse mass
a	1.5 mg	1.4 mg
b	1.7 mg	1.8 mg
c	2.6 mg	2.9 mg
d	3.1 mg	3.8 mg
e	3.6 mg	5.0 mg
f	4.7 mg	6.5 mg
g	6.2 mg	8.7 mg
h	7.0 mg	10.6 mg
i	8.7 mg	12.7 mg
j	10.2 mg	14.6 mg

Raw data: circles & ellipses (main data of paper)

alpha1p00.zip -- trajectories of the alpha=1.00 particle
alpha1p44.zip -- trajectories of the alpha=1.44 particle
alpha1p48.zip -- trajectories of the alpha=1.48 particle
alpha2p20.zip -- trajectories of the alpha=2.20 particle

The forcing is as above for the bath particles. For example, files labeled "2p5" correspond to a magnetic field of 30 G. For most conditions there are three separate experiments; in a few cases there are only two, if something had gone wrong with one of the experiments. The data are (x,y,theta,time,ID) as described above. Fig. 5: The trajectories shown in Fig. 5 correspond to files tri5p5_1.txt and tri2p5_3.txt within the alpha2p20 zip file.

MSD data: Figs. 4 and 6

msd.zip: The zip file contains the MSD data for all experiments. The format of the MSD files for the bath particles is [dt (seconds), < delta x >, < delta y >, < (delta x)^2 >, < (delta y)^2 >, < (delta r)^2 >, N] where displacements are measured in mm, and N relates to how much data there is (see this webpage for explanation of N). The format of the MSD files for the other data sets is [dt (frames), dr^2, dtheta^2] where you can divide dt by 60 to convert to seconds. The dr^2 are in mm^2 and dtheta^2 is in degrees^2.

If you need more data (non-Gaussian files, measured diffusion constants) please contact Eric Weeks.