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Cryogenic grinding, also known as freezer milling, freezer grinding, and cryomilling, is the act of cooling or chilling a material and then reducing it into a small particle size. For example, thermoplastics are difficult to grind to small particle sizes at ambient temperatures because they soften, adhere in lumpy masses and clog screens.
In developmental, cell and molecular biology, trituration is the process of fragmenting of solid material (often biological tissue or aggregated material) into smaller components (often, respectively, cells or molecules in suspension/solution) by means of repeated passage through a pipette.
In molecular biology, treadmilling is a phenomenon observed within protein filaments of the cytoskeletons of many cells, especially in actin filaments and microtubules. It occurs when one end of a filament grows in length while the other end shrinks, resulting in a section of filament seemingly "moving" across a stratum or the cytosol.
Traditional micronization techniques are based on friction to reduce particle size. Such methods include milling, bashing and grinding.A typical industrial mill is composed of a cylindrical metallic drum that usually contains steel spheres.
Form-milling uses either a single- or multiple-form cutter. In one variant of form-milling, the single-form cutter is tilted to the helix angle of the thread and then fed radially into the blank. The blank is then slowly rotated as the cutter is precisely moved along the axis of the blank, which cuts the thread into the blank.
In form milling, the cutter called a form cutter travels axially along the length of the gear tooth at the appropriate depth to produce the gear tooth. After each tooth is cut, the cutter is withdrawn, the gear blank is rotated, and the cutter proceeds to cut another tooth.
Most widespread instruments are using liquid metal ion sources (LMIS), especially gallium ion sources. Ion sources based on elemental gold and iridium are also available. In a gallium LMIS, gallium metal is placed in contact with a tungsten needle, and heated gallium wets the tungsten and flows to the tip of the needle, where the opposing forces of surface tension and electric field form the ...
In biology, the ribosome provides an example of a programmable mechanosynthetic device. A non-biological form of mechanochemistry has been performed at cryogenic temperatures using scanning tunneling microscopes. [1] So far, such devices provide the closest approach to fabrication tools for molecular engineering.