Electron microscopes have certain advantages over optical microscopes: The biggest advantage is that they have a higher resolution and are therefore also able of a higher magnification (up to 2 million times). Light microscopes can show a useful magnification only up to 1000-2000 times. This is a physical limit imposed by the wavelength of the light. Electron microscopes therefore allow for the visualization of structures that would normally be not visible by optical microscopy.
berm (plural berms) A narrow ledge or shelf, as along the top or bottom of a slope. A raised bank or path, especially the bank of a canal opposite the towpath. A terrace formed by wave action along a beach. A mound or bank of earth, used especially as a barrier or to provide insulation.
A beret (UK /ËbÉreÉª/ BERR-ay or US /bÉËreÉª/ bÉ-RAY; [beÊÉ]) is a soft, round, flat-crowned hat, usually of woven, hand-knitted wool, crocheted cotton, wool felt, or acrylic fibre. Mass production began in 19th century France and Spain, countries with which it remains associated.he black beret was once considered the national cap of France in Anglo-Saxon countries and is part of the stereotypical image of the Onion Johnny. It is no longer as widely worn as it once was, but it remains a strong sign of local identity in the southwest of France.