tungsten metal powder
51Mathematics 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… …
52Arc welding — uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non consumable electrodes.… …
53X-ray tube — An X ray tube is a vacuum tube that produces X rays. They are used in X ray machines. X rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X ray tubes evolved from experimental… …
54Dry lubricant — Dry lubricants or solid lubricants are materials which despite being in the solid phase, are able to reduce friction between two surfaces sliding against each other without the need for a liquid media. Such lubricants, including materials such as …
55Cartridge (firearms) — From left: .50 BMG, .300 Win Mag, .308 Winchester, 7.62×39mm, 5.56×45mm NATO, .22LR. A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm …
56Caesium — xenon ← caesium → barium Rb ↑ Cs ↓ Fr …
57Lubricant — A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat. The property of reducing friction is known as lubricity. A good lubricant… …
58Magnesium — Not to be confused with Manganese. sodium ← magnesium → aluminium Be ↑ Mg ↓ Ca …
59Niobium — zirconium ← niobium → molybdenum V ↑ Nb ↓ Ta …
60Shotgun — For other uses, see Shotgun (disambiguation). A pump action Remington 870, two semi automatic …
