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A loudspeaker is composed of a permanent magnet, copper wire, paper, etc. Everything that can be identified as a homogeneous material must meet the limit. So if it turns out that the case was made of plastic with 2,300 ppm (0.23%) PBB used as a flame retardant, then the entire radio would fail the requirements of the directive.
A pooled analysis found consistent evidence of an effect of ELF-MF on childhood leukaemia. [23] An assessment of the burden of disease potentially resulting from ELF MF exposure in Europe found that 1.5–2% of childhood leukaemia cases might be attributable to ELF MF, but uncertainties around causal mechanisms and models of dose-response were ...
Galvanic systems are "constant potential" systems that aim to restore the concrete's natural protective environment by providing a high initial current to restore passivity. It then reverts to a lower sacrificial current, while harmful negative chloride ions migrate away from the steel and towards the positive anode.
An example of a water distribution system: a pumping station, a water tower, water mains, fire hydrants, and service lines [1] [2]. A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements.
The river water was contaminated with toxic metals including arsenic, copper, barium, cadmium, chromium, lead, mercury, nickel, and thallium. [2] Cleanup costs may exceed $1.2 billion. [3] A toxic heavy metal is a common but misleading term for a metal-like element noted for its potential toxicity. [4]
Corona discharge usually forms at highly curved regions on electrodes, such as sharp corners, projecting points, edges of metal surfaces, or small diameter wires. The high curvature causes a high potential gradient at these locations so that the air breaks down and forms plasma there first.
A farm in the mountains of Norway stands on the site of what was once a “large and powerful Viking farm” and has yielded a significant Viking treasure.
In both those instances the white wire should be identified as being hot, usually with black tape inside junction boxes. The neutral wire is identified by gray or white insulated wire, perhaps using stripes or markings. With lamp cord wire the ribbed wire is the neutral, and the smooth wire is the hot. NEC 2008 400.22(f) allows surface marking ...