Swiss roll

A Swiss roll, jelly roll, or cream roll is a type of sponge cake roll filled with whipped cream, jam, or icing.

The origins of the term are unclear. In spite of the name Swiss roll, the cake is believed to have originated elsewhere in Central Europe, likely Austria. It appears to have been invented in the nineteenth century, along with Battenberg, doughnuts and Victoria sponge.

The shape of the Swiss roll has inspired usage as a descriptive term in other fields, such as in optics and many forms of the term "jelly roll".

History

Jelly Cake (layer cake) is an old English recipe. The earliest published reference for a rolled cake spread with jelly was in the Northern Farmer, a journal published in Utica, New York, in December 1852. Called “To Make Jelly Cake”, the recipe describes a modern "jelly roll" and reads: “Bake quick and while hot spread with jelly. Roll carefully, and wrap it in a cloth. When cold cut in slices for the table.”

The terminology evolved in America for many years. From 1852 to 1877 such a dessert was called: Jelly Cake (1852), Roll Jelly Cake (1860), Swiss Roll (1872), Jelly Roll (1873), and Rolled Jelly Cake (1876). The name “Jelly Roll” was eventually adopted.

Split-ring resonator

A split-ring resonator (SRR) is an artificially produced structure common to metamaterials. Their purpose is to produce the desired magnetic susceptibility (magnetic response) in various types of metamaterials up to 200 terahertz. These media create the necessary strong magnetic coupling to an applied electromagnetic field, not otherwise available in conventional materials. For example, an effect such as negative permeability is produced with a periodic array of split ring resonators.

A single cell SRR has a pair of enclosed loops with splits in them at opposite ends. The loops are made of nonmagnetic metal like copper and have a small gap between them. The loops can be concentric, or square, and gapped as needed. A magnetic flux penetrating the metal rings will induce rotating currents in the rings, which produce their own flux to enhance or oppose the incident field (depending on the SRRs resonant properties). This field pattern is dipolar. Due to splits in the rings the structure can support resonant wavelengths much larger than the diameter of the rings. This would not happen in closed rings. The small gaps between the rings produces large capacitance values which lower the resonating frequency. The dimensions of the structure are small compared to the resonant wavelength. This results in low radiative losses, and very high quality factors.