Search results
Results from the WOW.Com Content Network
One of the largest deliberate PCB spills in American history occurred in the summer of 1978 when 31,000 gallons (117 m^3) of PCB-contaminated oil were illegally sprayed by the Ward PCB Transformer Company in 3-foot (0.91 m) swaths along the roadsides of some 240 miles (390 km) of North Carolina highway shoulders in 14 counties and at the Fort ...
General structure of a PCB. Polychlorinated biphenyls (PCBs) are various biphenyl based artificial products that are widely used as a dielectric fluid, industrial coolant, and lubricants in the 1960s and 1970s. There is no evidence its synthesis occurs naturally. They are classified as persistent organic pollutants.
A printed circuit board (PCB), also called printed wiring board (PWB), is a laminated sandwich structure of conductive and insulating layers, each with a pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto or between sheet layers of a non-conductive ...
Congener descriptors give a shorthand notation for geometry and substituent positions. The twelve congeners that display all four of the descriptors are referred to as being "dioxin-like", referring both to their toxicity and structural features which make them similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD). [1]
The PCB of a quartz watch. The clock IC is under the drop of black epoxy. Chip on board (COB) is a method of circuit board manufacturing in which integrated circuits (e.g. microprocessors) are attached (wired, bonded directly) to a printed circuit board, and covered by a blob of epoxy. [1]
A milled printed circuit board. Printed circuit board milling (also: isolation milling) is the milling process used for removing areas of copper from a sheet of printed circuit board (PCB) material to recreate the pads, signal traces and structures according to patterns from a digital circuit board plan known as a layout file. [1]
The process can be used to provide important benchmarking information about newly acquired products, prototype PCBs or any circuit board the company does not own. For example, reverse engineering a circuit assembly reveals whether or not the fabricator has exactly matched the design specifications of the board.
In 1986, PCB developed the first commercial quartz shear-structured ICP® accelerometer. Additionally in 1980, PCB® broke ground on 6 acres (24,000 m 2) of land at 3425 Walden Avenue for its new quartz technology center, a location which it continues to occupy today. The facility doubled in size in 1985, and in 1996 an additional was added.