Alloys of 85–88% zinc, 4–10% copper, and 2–8% aluminium find limited use in certain types of machine bearings. Zinc has been the primary metal in American one cent coins (pennies) since 1982. The zinc core is coated with a thin layer of copper to give the appearance of a copper coin. In 1994, 33,200 tonnes (36,600 short tons) of zinc were used to produce 13.6 billion pennies in the United States.Alloys of zinc with small amounts of copper, aluminium, and magnesium are useful in die casting as well as spin casting, especially in the automotive, electrical, and hardware industries. These alloys are marketed under the name Zamak. An example of this is zinc aluminium. The low melting point together with the low viscosity of the alloy makes possible the production of small and intricate shapes. The low working temperature leads to rapid cooling of the cast products and fast production for assembly. Another alloy, marketed under the brand name Prestal, contains 78% zinc and 22% aluminium, and is reported to be nearly as strong as steel but as malleable as plastic. This superplasticity of the alloy allows it to be molded using die casts made of ceramics and cement.Similar alloys with the addition of a small amount of lead can be cold-rolled into sheets. An alloy of 96% zinc and 4% aluminium is used to make stamping dies for low production run applications for which ferrous metal dies would be too expensive.
Pigmented purpuric dermatosis refers to one of the three major classes of skin conditions characterized by purpuric skin eruptions. Pigmented purpuric dermatosis are distinguished from other purpura by size (0.3–1 cm) and are most often seen in the lower extremities. : 829   Pigmentary purpuric eruptions may present with one of several clinical patterns. There may be overlapping characteristics among pigmented purpuric dermatosis and between their signs and those of other purpuric eruptions. : 829   Examples of the pigmented purpuric dermatosis group include:: 829–30 
Schambergs disease
Majocchis disease (Purpura annularis telangiectodes)
Gougerot-Blum syndrome (Pigmented purpuric lichenoid dermatitis)
Ducas and Kapetanakis pigmented purpura
Lichen aureusAlthough vascular damage may be present, it is insufficient for these conditions to be considered forms of vasculitis.A few very small non-blinded studies of treatment with narrow-band ultraviolet light have been reported as promising. See also
Purpura
Skin lesion
List of cutaneous conditions

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