Ozone layer radiation was matched to only one known chemical, ozone. Its properties were explored in detail by the British meteorologist G. M. B. Dobson, who developed a simple spectrophotometer (the Dobsonmeter) that could be used to measure stratospheric ozone from the ground. Between 1928 and 1958, Dobson established a worldwide network of ozone monitoring stations, which continue to operate to this day. The "Dobson unit", a convenient measure of the amount of ozone overhead, is named in his honor. The ozone layer absorbs 97 to 99 percent of the Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength),
Layer Jump Recording Layer Jump Recording Layer Jump Recording (LJR) is a writing method used for DVD-R DL (Dual Layer). It permits recording the disc per increments called session (see Optical disc authoring), a.k.a. multi-session. It also permits a faster closing of the disc by saving extraneous padding when the amount of recorded data does not fill-up the disc. It overcomes these limitations of Sequential Recording (SR), the writing method usually applied to write-once optical media. The layer jump is a switch (jump) between the layer closer to the laser head (referred as L0) to the farther layer (referred as L1), or vice