| Raney catalyst | Proprietary name for a finely powdered nickel catalyst made from Raney alloy by dissolving out the aluminum with alkali; used in the hydrogenation of organic substances. Synonym: Raney catalyst. (05 Mar 2000) |
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| catalyst | <chemistry> A substance that accelerates a chemical reaction, but is not consumed or changed in the process. (16 Mar 1998) |
| organic catalyst | A catalyst that is an organic molecule. See: enzyme, ribozyme. (05 Mar 2000) |
| non-ionic contrast media | <radiology> A class of radiographic contrast media which do not ionise in solution, thereby decreasing effective osmolarity and toxicity. (05 Mar 2000) |
| ionic | Relating to an ion. (05 Mar 2000) |
| ionic coupling | <chemistry> The same as electrical coupling. (18 Nov 1997) |
| ionic medication | Movement of ions as a result of an applied electric field. For example the delivery of a charged molecule from the end of a micropipette without hydraulic flow. (18 Nov 1997) |
| ionic strength | Symbolised as g/2 or I and set equal to 0.5σmizi2, where mi equals the molar concentration and zi the charge of each ion present in solution; if molar concentrations (ci) are used instead of molality (and the solution is dilute), then I == 0.5(1/ρo)σcizi2 where ρo is the density of the solvent; a number of biochemically important events (e.g., protein solubility and rates of enzyme action) vary with the ionic strength of a solution. (05 Mar 2000) |