FILAMENTS

• The first successful light bulb filaments were made of carbon (from carbonized paper or bamboo), later replaced with tungsten. improve the efficiency of the lamp, the filament usually consists of coils of fine wire, also known as a 'coiled coil.' For a 60-watt 120-volt lamp, the uncoiled length of the tungsten filament is usually 22.8 inches or 580 mm , and the filament diameter is 0.0018 inches (0.045 mm).

• The advantage of the coiled coil is that evaporation of the tungsten filament is at the rate of a tungsten cylinder having a diameter equal to that of the coiled coil. Due to the coils creating gaps, such a filament has a lower surface area than the perceived surface area of the filament, and so evaporation is reduced. If the filament is then run hotter to bring back evaporation to the same rate, the resulting filament is a more efficient light sou

• There are several different shapes of filament used in lamps, with differing characteristics. Manufacturers designate the types with codes such as C-6, CC-6, C-2V, CC-2V, C-8, CC-88, C-2F, CC-2F, C-Bar, C-Bar-6, C-8I, C-2R, CC-2R, and Axial.

Electrical filaments are also used in hot cathodes of fluorescent lamps and vacuum tubes as a source of electrons or in vacuum tubes to heat an electron-emitting electrode.

• Filaments is a library package that can be used to create architecture-independent parallel programs---that is, programs that are portable efficient across vastly different parallel machines. Filaments virtualizes the underlying machine in terms of the number of processors and the interconnection. This simplifies parallel program design in two ways. First, programs can be written (or generated) with the focus on the parallelism inherent in the application, not the architecture.

1. Outline of Glass bulb
2. Low pressure inert gas (argon, neon, nitrogen)
3. Tungsten filament
4. Contact wire (goes out of stem)
5. Contact wire (goes into stem)
6. Support wires
7. Stem (glass mount)
8. Contact wire (goes out of stem)
9. Cap (sleeve)
10 Insulation (vitrite)
11 Electrical contact

• Second, programs can be written that use familiar shared-variable communication. Furthermore, Filaments uses a carefully designed API along with machine-specific runtime libraries and preprocessing that allow programs to run unchanged on both shared- and distributed-memory machines. Most importantly, applications programmed in Filaments run efficiently, achieving a speedup of over 4 on 8 processors or nodes in almost all tests that have been performed.