#electromagnetics

This is what I get to do for my research <3 I love watching the patterns play out

If you've ever ask yourself what the use of math is, here's a great example. These patterns are simulated electromagnetic waves that are generated based on Maxwell's equations - which are partial differential equations. The computer has to calculate multiple values for each grid cell displayed, then calculates the next grid cell off of the previous and surrounding values.

so fun! and even when i mess things up, the patterns still look cool

The Montauk Project (Experiments in Time) by Preston B. Nichols and Peter Moon

You can read this for free:

Electrospun nanomaterial offers great protection against electromagnetic interference

Engineers have employed "electrospinning," a new technique of manufacturing nanomaterials, to produce a novel fabric that offers high performance protection against electromagnetic interference, a phenomenon that can result in electronic device malfunction and at high levels of exposure can harm human health.

The technique is described in a paper published in Nano Research on December 31, 2022.

Electric and magnetic fields generated by electrical equipment can negatively interfere with digital systems either internally or externally. Such disruption can result in dangerous malfunctions if such devices are operating close to each other, particularly in the case of transportation or medical equipment such as pacemakers and insulin pumps. This interference can not only affect electronic devices, but at very high levels over short periods, it can also put at risk human biology, which in part makes use of bioelectromagnetic processes.

For all these reasons, a great deal of effort goes into shielding people, devices and parts of devices from electromagnetic interference. To avoid making devices—particularly wearable ones—overly bulky and heavy, such shielding also needs to be lightweight and flexible.

Credit: David Citrin. This image shows reflected raw terahertz signals measured across the painting.

What’s new?

Using terahertz scanners and advanced signal processing techniques, developed for petroleum exploration, an unprecedented insight into the layers of 17th Century artwork has been gained.

Using a commercial terahertz scanner, the research team studied Madonna in Preghiera by the workshop of Giovanni Battista Salvi da Sassoferrato, loaned from the Musée de la Cour d’Or, Metz Métropole, France. Described in the paper as typical of the period and having previously resisted attempts to analyse its stratigraphy (the order and distribution of layers of paint) – due to the layers measuring only tens of micrometres – it is an oil painting on canvas, mounted on a wooden stretcher.

Who is involved?

Researchers at the Georgia Institute of Technology, USA, detailed the new technique in Global mapping of stratigraphy of an old-master painting using sparsity-based terahertz reflectometry, published in Scientific Reports. 

How is it novel?

The scanner’s electromagnetic wave generator emits signals that penetrate layers of paint. Different pigments and physical structures, such as imperfections in the layers, are revealed by wavelengths as they reflect some of the beam back to the scanner. Oil paint and newer varnish do not fluoresce under UV – meaning recent retouchings appear as darker patches on the surface.

The collected data was processed by a computer-based signal processing technique – sparsity-based time-domain deconvolution – and a three-dimensional map of the image was constructed using the signals reflected from each layer. The team was able to identify layers including the canvas support, ground (the background surface), imprimatura (the initial colour stain painted on the ground), underpainting, pictorial and varnish layers. A formerly unknown layer of varnish restoration was also detected.

To read more on this topic see the upcoming January issue of Materials World.