copper matrix
21Stone Age — the period in the history of humankind, preceding the Bronze Age and the Iron Age, and marked by the use of stone implements and weapons: subdivided into the Paleolithic, Mesolithic, and Neolithic periods. [1860 65] * * * First known period of… …
22Printed circuit board — Part of a 1983 Sinclair ZX Spectrum computer board; a populated PCB, showing the conductive traces, vias (the through hole paths to the other surface), and some mounted electrical components A printed circuit board, or PCB, is used to… …
23Shaped charge — Sectioned high explosive anti tank round with the inner shaped charge visible …
24Aneurysm — For other uses, see Aneurysm (disambiguation). Aneurysm Classification and external resources Angiography of an aneurism in a cerebral artery ICD 10 I …
25Kambalda type komatiitic nickel ore deposits — Kambalda type nickel ore deposits are a class of magmatic nickel copper ore deposit in which the physical processes of komatiite volcanology serve to enrich, concentrate and deposit nickel bearing sulfide within the lava flow environment of an… …
26Johannes Gutenberg — Infobox Person | name = Johannes Gensfleisch zur Laden zum Gutenberg other names = caption = birth date = circa 1398 birth place = Mainz, Electorate of Mainz death date = death date|1468|2|3|mf=y death place = Mainz, Electorate of Mainz death… …
27Native metal — Kondyor Mine Region Chabarowsk: native platinum nugget A native metal is any metal that is found in its metallic form, either pure or as an alloy, in nature. Metals that can be found as native deposits singly and/or in alloys include aluminium,… …
28Japanese Industrial Standards — This article is about Japanese Industrial Standards in general; see JIS encoding for the character encoding used in representing the Japanese language for computer software and communication. Japanese Industrial Standards (JIS) specifies the… …
29materials science — the study of the characteristics and uses of various materials, as glass, plastics, and metals. [1960 65] * * * Study of the properties of solid materials and how those properties are determined by the material s composition and structure, both… …
30atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …
