Physics Research Workshttp://hdl.handle.net/1903/15972019-12-15T00:00:39Z2019-12-15T00:00:39ZData for the figures in the paper "Turbulence and Transport During Guide-Field Reconnection at the Magnetopause"Price, LSwisdak, MDrake, JFGraham, DBhttp://hdl.handle.net/1903/252112019-10-05T07:45:24Z2019-01-01T00:00:00ZData for the figures in the paper "Turbulence and Transport During Guide-Field Reconnection at the Magnetopause"
Price, L; Swisdak, M; Drake, JF; Graham, DB
We analyze the development and influence of turbulence in three-dimensional particle-in-cell simulations of guide-field magnetic reconnection at the magnetopause with parameters based on observations of an electron diffusion region by the Magnetospheric Multiscale (MMS) mission. Along the separatrices the turbulence is a variant of the lower hybrid drift instability (LHDI) that produces electric field fluctuations with amplitudes much greater than the reconnection electric field. The turbulence controls the scale length of the density and current profiles while enabling significant transport across the magnetopause despite the electrons remaining frozen-in to the magnetic field. Near the X-line the electrons are not frozen-in and the turbulence, which differs from the LHDI, makes a significant net contribution to the generalized Ohm's law through an anomalous viscosity. The characteristics of the turbulence and associated particle transport are consistent with fluctuation amplitudes in the MMS observations. However, for this event the simulations suggest that the MMS spacecraft were not close enough to the core of the electron diffusion region to identify the region where anomalous viscosity is important.
Data and auxiliary IDL codes to reproduce the figures from the paper "Turbulence and Transport During Guide-Field Reconnection at the Magnetopause" by L. Price, M. Swisdak, J. F. Drake, and D. B. Graham
2019-01-01T00:00:00ZRaw Experimental Data for work presented in "Imaging collective behavior in an rf-SQUID metamaterial tuned by DC and RF magnetic fields"Zhuravel, AlexanderBae, Seokjinhttp://hdl.handle.net/1903/217322019-04-11T12:54:15Z2019-01-01T00:00:00ZRaw Experimental Data for work presented in "Imaging collective behavior in an rf-SQUID metamaterial tuned by DC and RF magnetic fields"
Zhuravel, Alexander; Bae, Seokjin
We examine the collective behavior of two-dimensional nonlinear superconducting metamaterials using a non-contact spatially resolved imaging technique. The metamaterial is made up of sub-wavelength nonlinear microwave oscillators in a strongly coupled 27x27 planar array of radio-frequency Superconducting QUantum Interference Devices (rf-SQUIDs). By using low temperature laser scanning microscopy we image microwave currents in the driven SQUIDs while in non-radiating dark modes and identify the clustering and uniformity of like-oscillating meta-atoms. We follow the rearrangement of coherent patterns due to meta-atom resonant frequency tuning as a function of external dc and rf magnetic flux bias. We find that the rf current distribution
across the SQUID array at zero dc flux and small rf flux reveals a low degree of coherence. By contrast, the spatial coherence improves dramatically upon increasing of rf flux amplitude, in agreement with simulation. The paper can be accessed here: https://doi.org/10.1063/1.5064658
This is the raw data in Figs. 2, 3, and 4 of the main text of the paper.
2019-01-01T00:00:00ZData for "Quantifying Dissipation in Actomyosin Networks"Floyd, CarlosPapoian, GareginJarzynski, Christopherhttp://hdl.handle.net/1903/215632019-01-24T13:52:26Z2019-01-01T00:00:00ZData for "Quantifying Dissipation in Actomyosin Networks"
Floyd, Carlos; Papoian, Garegin; Jarzynski, Christopher
Quantifying entropy production in various active matter phases would open new avenues for probing self-organization principles in these far-from-equilibrium systems. It has been hypothesized that the dissipation of free energy by active matter systems may be optimized to produce highly dissipative dynamical states, hence, leading to spontaneous emergence of more ordered states. This interesting idea has not been widely tested. In particular, it is not clear whether emergent states of actomyosin networks, which represent one of the most salient examples of biological active matter, self-organize following the principle of dissipa- tion optimization. In order to start addressing this question using detailed computational modeling, we rely on the MEDYAN simulation platform, which allows simulating active matter networks from fundamental molecular principles. We have extended the capabilities of MEDYAN to allow quantification of the rates of dissipation resulting from chemical re- actions and relaxation of mechanical stresses during simulation trajectories. This is done by computing precise changes in Gibbs free energy accompanying chemical reactions using a novel formula, and through detailed calculations of instantaneous values of the systemâ€™s mechanical energy. We validate our approach with a mean-field model that estimates the rates of dissipation from filament treadmilling. Applying this methodology to the self- organization of small disordered actomyosin networks, we find that compact and highly cross-linked networks tend to allow more efficient transduction of chemical free energy into mechanical energy. In these simple systems, we do not observe that spontaneous network reorganizations lead to increases in the total dissipation rate as predicted by the dissipation- driven adaptation hypothesis mentioned above. However, whether such a principle operates in more general, more complex cytoskeletal networks remains to be investigated.
This is contains the source code and data set used for the paper "Quantifying Dissipation in Actomyosin Networks."
2019-01-01T00:00:00ZRaw Experimental Data for work presented in "Scattering Statistics in Nonlinear Wave Chaotic Systems"Zhou, Minhttp://hdl.handle.net/1903/215622019-01-24T08:45:30Z2019-01-23T00:00:00ZRaw Experimental Data for work presented in "Scattering Statistics in Nonlinear Wave Chaotic Systems"
Zhou, Min
Raw experimental data for the work presented in "Scattering Statistics in Nonlinear Wave Chaotic Systems," published in the Journal Chaos.
The dataset includes raw data files, Matlab code to analyze the data, and related CST simulations.
2019-01-23T00:00:00Z