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Full-Text Articles in Physics

Superfluid Swimmers, German Kolmakov, Igor S. Aranson Feb 2021

Superfluid Swimmers, German Kolmakov, Igor S. Aranson

Publications and Research

The propulsion of living microorganisms ultimately relies on viscous drag for body-fluid interactions. The self-locomotion in superfluids such as 4He is deemed impossible due to the apparent lack of viscous resistance. Here, we investigate the self-propulsion of a Janus (two-face) light-absorbing particle suspended in superfluid helium 4He (He-II). The particle is energized by the heat flux due to the absorption of light from an external source. We show that a quantum mechanical propulsion force originates due to the transformation of the superfluid to a normal fluid on the heated particle face. The theoretical analysis is supported by the …


Understanding Of Aerosol Transmission Of Covid 19 In Indoor Environments, Adama Barro, Cathal O'Toole, Jacob S. Lopez, Matthew Quinones, Sherene Moore Dec 2020

Understanding Of Aerosol Transmission Of Covid 19 In Indoor Environments, Adama Barro, Cathal O'Toole, Jacob S. Lopez, Matthew Quinones, Sherene Moore

Publications and Research

Our reason for discussing severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) or 2019 novel corona virus (Covid-19), is to understand its aerosol transmission characteristics in indoor spaces and to mitigate further spread of this disease by designing a new HVAC system. The problem that we are tackling is the spread of covid-19 droplets through aerosol transmission by looking at potential engineering solutions to the existing HVAC systems. The purpose is to eradicate the spread of the COVID-19 by testing indoor spaces in an effort to understand the effectiveness of ventilation controls. We believe that scientists and engineers have not …


Microfluidic Study Of The Electrocoalescence Of Aqueous Droplets In Crude Oil, Thomas Leary, Mohsen Yeganeh, Charles Maldarelli Mar 2020

Microfluidic Study Of The Electrocoalescence Of Aqueous Droplets In Crude Oil, Thomas Leary, Mohsen Yeganeh, Charles Maldarelli

Publications and Research

In electrocoalescence, an electric field is applied to a dispersion of conducting water droplets in a poorly conducting oil to force the droplets to merge in the direction of the field. Electrocoalescence is used in petroleum refining to separate water from crude oil and in droplet-based microfluidics to combine droplets of water in oil and to break emulsions. Using a microfluidic design to generate a two-dimensional (2D) emulsion, we demonstrate that electrocoalescence in an opaque crude oil can be visualized with optical microscopy and studied on an individual droplet basis in a chamber whose height is small enough to make …


Dynamic Self-Assembly And Self-Organized Transport Of Magnetic Micro-Swimmers, Gašper Kokot, German Kolmakov V, Igor S. Aranson, Alexey Snezhko Nov 2017

Dynamic Self-Assembly And Self-Organized Transport Of Magnetic Micro-Swimmers, Gašper Kokot, German Kolmakov V, Igor S. Aranson, Alexey Snezhko

Publications and Research

We demonstrate experimentally and in computer simulations that magnetic microfloaters can self-organize into various functional structures while energized by an external alternating (ac) magnetic field. The structures exhibit self-propelled motion and an ability to carry a cargo along a pre-defined path. The morphology of the self-assembled swimmers is controlled by the frequency and amplitude of the magnetic field.