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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.
Dark oxygen production refers to the generation of molecular oxygen (O 2) through processes that do not involve light-dependent oxygenic photosynthesis.The name therefore uses a different sense of 'dark' than that used in the phrase "biological dark matter" (for example) which indicates obscurity to scientific assessment rather than the photometric meaning.
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 ...
In some cases, simply changing the way the material is processed can influence the microstructure. An example is the titanium alloy TiAl6V4. [12] Its microstructure and mechanical properties are enhanced using SLM (selective laser melting) which is a 3D printing technique using powder and melting the particles together using high powered laser ...
In annular dark-field mode, images are formed by fore-scattered electrons incident on an annular detector, which lies outside of the path of the directly transmitted beam. By using a high-angle ADF detector, it is possible to form atomic resolution images where the contrast of an atomic column is directly related to the atomic number (Z ...
The laboratory is divided in seven research teams, which have their own field of research : TMP : Texture, microstructure and process; MeNu : computational mechanics; APLI : Auto-organization, plasticity and intern lengths; 3TAM : transformation, textures, topology and metal anisotropy; SMART : Multi-phased systems, rheology, fatigue and ...
Irradiation of oxygen gas in the presence of an organic dye as a sensitizer, such as rose bengal, methylene blue, or porphyrins—a photochemical method—results in its production. [19] [9] Large steady state concentrations of singlet oxygen are reported from the reaction of triplet excited state pyruvic acid with dissolved oxygen in water. [20]
The best known explanation of the oxygen effect is the oxygen fixation hypothesis developed by Alexander in 1962, [9] which posited that radiation-induced non-restorable or "fixed" nuclear DNA lesions are lethal to cells in the presence of diatomic oxygen. [10] [11] Recent hypotheses include one based on oxygen-enhanced damage from first ...