welding zinc- coated steel
21Titanium — This article is about the chemical element. For other uses, see Titanium (disambiguation). scandium ← titanium → vanadium …
22Metalworking — Machining a bar of metal on a lathe. Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts… …
23metalwork — metalworker, n. /met l werrk /, n. objects made of metal. [1840 50; METAL + WORK] * * * Useful and decorative objects fashioned of various metals. The oldest technique is hammering. After с 2500 BC, casting was also used, molten metal being… …
24Mechanical plating — Mechanical plating, also known as peen plating, mechanical deposition, or impact plating, is a plating process that imparts the coating by cold welding fine metal particles to a workpiece. Mechanical galvanization is the same process, but applies …
25Roof — A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most… …
26Disasters — ▪ 2009 Introduction Aviation January 23, Poland. A Spanish built CASA transport plane carrying members of the Polish air force home from a conference on flight safety in Warsaw crashes near the town of Miroslawiec; all 20 aboard are killed …
27Fuel cell — For other uses, see Fuel cell (disambiguation). Demonstration model of a direct methanol fuel cell. The actual fuel cell stack is the layered cube shape in the center of the image A fuel cell is a device that converts the chemical energy from a… …
28Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
29Niobium — zirconium ← niobium → molybdenum V ↑ Nb ↓ Ta …
30Copper — For other uses, see Copper (disambiguation) …
