Piped Lighting Effect

Fig. 17-2. Effect of bulb location on collimation of light when piping light through transparent acrylic rod. Courtesy E. L DuPont)...

Bimetallic cluster assemb lies and nano-structures act as unidirectional light pipes. The effect is attributed to plasmon propagation. The combination of 2 nano-clusters with non identical band gaps are an optical analogue to a diode, and thus may be used to construct e.g. optically addressable memory elements or nano-sensors. 

Besides large-diameter pipes, ultrasonic testing is used for checking the welded joints of drill bits, components of wind-driven electric plants, welded joints of light alloys and non-metallic materials, for an integrated inspection of various objects. A range of training aids developed at the Institute allows the operators to be trained effectively. 

A study was made of the effects of processing conditions and of blowing and nucleating agents and external lubricants on the apparent density, mechanical properties, linear thermal expansion coefficient and surface roughness of extruded cellular MDPE. Based on the results, recommendations were formulated for the properties of cellular MDPE pipes for the protection of light conducting cables. 16 refs. (Translation of Polimery, Tworzywa Wielkoczasteczkowe, No. 10, 1996, p.580). 

Support spacing must be much closer than for carbon steel. As temperature increases, the allowable stress for many plastic pipes decreases very rapidly, and heat from sunlight or adjacent hot uninsiuated equipment has a marked effect. Many plastics deteriorate with exposure to ultraviolet light if not provided with a UV-resistant coating or other surface barrier. Successful economical underground use of plastic pipe does not necessarily indicate similar economies outdoors aboveground. 

Detailed analysis leads to the results shown in Fig 6, which compares computations for the open-end and closed-end pipes . Note that dimensionless piston velocities coincide above c/m = 6.7 (r = c/m). The original explanation offered for this effect was that for rc = 6.7 the piston is so light that the rebounding shock cannot overtake it. Subsequent analysis indicated that r < 7.1 the rebounding shock does indeed overtake the piston. This discrepancy was resolved by a more detailed analysis which showed that effects of the rebounding shock of rc < r < 7.1 are so slight as to be indistinguishable by the numerical methods used in the computations... 

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