vesiniku keskkonnas keemilistest ühenditest (peam. metallioksiididest) taandatud pulber; saadud pulbrit iseloomustab pulbriosakeste suur sisemine poorsus ja/või eripind (vt vesiniktaandus), powder produced by the hydrogen reduction of a compound, usually oxide; the resulting powder often has a high surface area or large amount of internal porosity (see: hydrogen reduction)