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:


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.

image of trimer from experiment


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.


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:
namecircle massellipse mass
a1.5 mg1.4 mg
b1.7 mg1.8 mg
c2.6 mg2.9 mg
d3.1 mg3.8 mg
e3.6 mg5.0 mg
f4.7 mg6.5 mg
g6.2 mg8.7 mg
h7.0 mg10.6 mg
i8.7 mg12.7 mg
j10.2 mg14.6 mg


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

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.