Explorer from the UK With the help of the model built by him, reproduced the hand wash mechanics and estimated the time to remove from the skin and viruses. The article of the scientist was published in the magazine Physics of Fluids.
The benefits of observance of hygiene, in particular, hand washing to contain the spread of infections (including coronavirus) has long been doubtted. However, physics of this process is not sufficiently studied. The British scholar Paul Hammond has decided to fill the space.
In the two-dimensional model constructed by them, a thin film of the liquid divides the two rough surfaces moving relative to each other, under which their hands are understood. Particles are delayed in recesses, breaking out of which it is possible only with sufficient energy of water flow. “If you move your hands in relation to each other too neat and too slowly created by the current power fluid is not enough to overcome the holding particle,” emphasizes Hammond.
The results of the scientist modeling are consistent with existing hand washing regulations – in order to effectively clean the surface from the particles, it is necessary at least 20 seconds. For example, the same period of time is called in its recommendations for the control and prevention of US diseases.
In this case, chemical and biological processes are not taken into account when using soap, researcher recognizes. A number of physical phenomena were also not taken into account – as, for example, Brownian particle movement.