About 75 years ago, Williard F. Libby, a Professor of Chemistry at the University of Chicago, predicted that a radioactive isotope of carbon, known as carbon, would be found to occur in nature. Since carbon is fundamental to life, occurring along with hydrogen in all organic compounds, the detection of such an isotope might form the basis for a method to establish the age of ancient materials. Working with several collaboraters, Libby established the natural occurrence of radiocarbon by detecting its radioactivity in methane from the Baltimore sewer. In contrast, methane made from petroleum products had no measurable radioactivity. Carbon is produced in the upper atmosphere when cosmic rays bombard nitrogen atoms. The ensuing atomic interactions create a steady supply of c14 that rapidly diffuses throughout the atmosphere. Plants take up c14 along with other carbon isotopes during photosynthesis in the proportions that occur in the atmosphere; animals acquire c14 by eating the plants or other animals.
Panelling or paneling in the U. Panelling was developed in antiquity to make rooms in stone buildings more comfortable. In more modern buildings , such panelling is often installed for decorative purposes. Panelling, such as wainscoting and boiserie in particular, may be extremely ornate and is particularly associated with seventeenth and eighteenth century interior design , Victorian architecture in Britain , and its international contemporaries. Wainscot oak came from large, slow-grown forest trees, and produced boards that were knot-free, low in tannin , light in weight, and easy to work with. It was preferred to home-grown oak, especially in Holland and Great Britain, because it was a far superior product and dimensionally stable. The Oxford English Dictionary states that it derives from the Middle Low German wagenschot as well as wageschot or ‘wall-board’. Wainscot [ wageschot , Dutch], the inner wooden covering of a wall. To wainscot [ waegenschotten , Dutch], to line the walls with boards. A ‘wainscot’ was therefore a board of riven and later quarter-sawn oak, and wainscoting was the panelling made from it.
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