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The vaporized getter, usually a volatile metal, instantly reacts with any residual gas, and then condenses on the cool walls of the tube in a thin coating, the getter spot or getter mirror, which continues to absorb gas. This is the most common type, used in low-power vacuum tubes. Non-evaporable getter (NEG) [8] The getter remains in solid form.
The windows provide direct channels for Earth's surface to receive electromagnetic energy from the Sun, and for thermal radiation from the surface to leave to space. [3] Atmospheric windows are useful for astronomy , remote sensing , telecommunications and other science and technology applications.
In physics, the observer effect is the disturbance of an observed system by the act of observation. [1] [2] This is often the result of utilising instruments that, by necessity, alter the state of what they measure in some manner. A common example is checking the pressure in an automobile tire, which causes some of the air to escape, thereby ...
Levels of O 2 and CO 2 in tissue can influence blood flow and thereby influence washout of dissolved inert gas, but the magnitude of the oxygen window has no direct effect on inert-gas washout. The oxygen window provides a tendency for absorption of the gas quantities in the body such as pneumothoraces or decompression sickness (DCS) bubbles. [9]
Metallography allows the metallurgist to study the microstructure of metals. A micrograph of bronze revealing a cast dendritic structure Al-Si microstructure. Microstructure is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope above 25× magnification. [1]
Dark-field microscopy produces an image with a dark background Operating principles of dark-field and phase-contrast microscopies Dark-field microscopy is a very simple yet effective technique and well suited for uses involving live and unstained biological samples, such as a smear from a tissue culture or individual, water-borne, single-celled ...
The formation of Ni-poor kamacite proceeds by diffusion of Ni in the solid alloy at temperatures between 450 and 700 °C, and can only take place during very slow cooling, about 100 to 10,000 °C/Myr, with total cooling times of 10 Myr or less. [13] This explains why this structure cannot be reproduced in the laboratory.
A micrograph contains extensive details of microstructure. A wealth of information can be obtained from a simple micrograph like behavior of the material under different conditions, the phases found in the system, failure analysis, grain size estimation, elemental analysis and so on. Micrographs are widely used in all fields of microscopy.