Curved light pipes

To produce a curved tapered pipe, a flexible mold is used. This is bent to the required shape once the preform has been placed in position. It is also claimed that base plates can be simultaneously molded on by this method. These base plates are first preformed and then inserted into the mold where they become firmly bonded into the pole. Typical applications include poles for street lighting, flag poles and aerials. 

Bogen-lampe, /. arc lamp, -lampenkohle, /. arc carbon, -licht, n. arc light, -linie, /. curved line, -mass, n. circular measure, -rohr, n., -rBhre, /. bent or curved pipe or tube, -schweisaung, /. arc welding, -skala, /. curved scale, -spektrum, n. arc spectrum. Stiic n. curved piece (Brewing) return bend,... 

Two separate (and not necessarily related) readouts of the test are (a) flame spread along the surface of the specimen as a distance traveled by the boundary of a zone of flame over time and (b) smoke developed as a change in optical density (as a progress curve of light absorption percent) between the light source and the photoelectric cell mounted in the vent pipe. These data are used to calculate the respective FSI and SDI as described in the ASTM test procedure. The indexes are calculated as relative values to those of select grade oak (FSI arbitrarily set as 100) and inorganic reinforced cement board (FSI set as 0) surfaces under the specified conditions. 

In the Steiner Tunnel of ASTM E 84-1981a (cf. Section 3.2.1, Fig. 3.93), flame spreading is measured on a specimen with surface area of 7320 mm x 508 mm. In the horizontal vent pipe of 408 mm dia. at the outlet of the tunnel, changes in the intensity of a vertical light beam are recorded during the test procedure. The area under the intensity vs, time curve for the specimen is divided by that for a red oak specimen and multiplied by 100, to establish a numerical index for comparison of the performance of the material to that of an asbestos-cement board and of red oak, taking these as limit points of an arbitrary centesimal scale (0 and 100, respectively). 

Figure 4-10 Description of observed patterns of particle behavior in a horizontal pipe (Owens, 1969). Curve I, light solid loading curve II, heavy solid loading curve III, particle-free gas . <4, choking B, deposition, dune formation, saltation C, higher concentration in lower part of pipe Z), uniform suspension. (Reproduced by permission of/, of Fluid Mechanics, Pergamon Press.)...

Carbon black can be tolerated in a limited number of formulations where color is not a criterion. The pigment not only absorbs light, but is also reactive with those free-radical species that might be formed. Wire and cable insulation and pipe for outdoor applications can be protected this way. Films for mulching and water con-taimnent in ponds may be made from polyethylene containing carbon black. Five UV absorbers and their corresponding transmission curves are shown in Table 12.3 and... 

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