Spider leg

Fig. 4. Pipe or tubing die for in-line extmsion A, die body B, mandrel, pin, and male die part C, die, die bushing, and female part D, die-retaining ring E, die-retaining bolt F, die-centered bolt G, spider leg H, air hole I, seat for breaker plate J, ring for attachment to extmder and K, die land (15).

Current is transferred to these meshes using distributors called spiders . The spiders have legs which distribute current to the mesh. The location of the spiders and the distribution of the anode and cathode spider legs has been developed via extensive calculation and trial to minimise the resistance of the spider/membrane/ mesh combination and to ensure that the resistance to current flow is equal across the whole membrane area, thus ensuring that there are no localised non-uniform current paths. The spiders are shown in Fig. 18.5 and the distribution pattern is shown in Fig. 18.6. 

Piers Anthony (hipiers.com) was one of the first famous people to respond to my request. Piers is one of the world s most prolific fantasy writers and creator of the Xanth series. He s published more than a hundred novels, and I collaborated with him on our novel Spider Legs. Anthony s novel Ogre may have been the first original fantasy paperback ever to make the New York Times bestseller list. He sent his Top 10 words to me ... 

I think Scalzi is largely correct. For example, I did publish a novel Spider Legs with the big science-fiction publisher TOR, but TOR published it because I had collaborated with science-fiction and fantasy superstar Piers Anthony, who has published over a hundred novels. When I attempted to publish my four books in my Neoreality series, none of the major publishers was interested, and so I had to publish the series with a small publisher. Happily, the books were immediately and favorably reviewed in Analog magazine, one of the premiere science-fiction... 

Mazes for the Mind Computers and the Unexpected Mit den Augen des Computers The Pattern Book Fractals, Art, and Nature The Science of Aliens Spider Legs (with Piers Anthony)... 

The band occurring at about 345 nm could be assigned to absorptions involving the spider legs, as suggested by the extinction coefficient values s which are linearly dependent on the number of bithienyl pendants present in the molecule (2, 4, and 6). The extinction coefficient is known to be dependent upon the number of the thiophene units also in linear a-oligo thiophenes. 

Plastic tube and tubular films are formed continuously by extruding a polymer through an annular die. The annular flow channel is formed by the outer die body and the die mandrel. A number of annular die designs are currently employed. In the first, the mandrel is supported mechanically onto the outer die body by a number of fins called spider legs Fig. 12.41 illustrates this type of die. The flow is axisymmetric, and the only serious problem encountered in the cross-machine direction uniformity of the extruded product is that of weld lines and streaks caused by the presence of the spider legs, which split the flow. 

Even though these obstacles are far away from the die lip region, the polymer melt, at normal extrusion speeds, is unable to heal completely. That is, the macromolecules comprising the two layers that were split by the spider legs do not establish the entanglement level characteristic of the bulk at the prevailing shear rate and temperature. 

Fig. 28.6 Alcohol-induced periportal and centrilobular fibrosis, partially spider leg-like (Sirius red) (s. fig. 21.14)...

Die spider n. In extrusion, the legs or webs supporting the die core within the head of an in-line pipe, tubing, or blown-film die. In many pipe dies, the spider legs are cored to permit application of air or water for cooling the mandrel. 

Spider legs n. Film defect where the coating material on an upright surface separates or breaks and the liquid runs down in long, crooked channels. 

Spider lines n. In blow molding or pipe extrusion, visible marks parallel to the par-ison or pipe axis and corresponding to the positions of the spider legs. They are due to incomplete welding of the divided stream downstream of those legs. These lines are the exterior traces of weld surfaces that go through the annular wall, surfaces that are sometimes weaker than the material between them. 

The bridge with multiple probes has the advantage of being able to monitor various temperatures at different locations at the same time. This allows a very careful monitoring of the thermal conditions in the polymer melt throughout the material. It is often possible to incorporate temperature probes in spider legs, torpedoes, etc., to obtain information on the polymer temperature away from the outside wall. 

In these dies, the center line of the die is in line with the center line of the extruder. The central torpedo is supported by a number of spider legs, usually three or more. The spider legs are relatively thin and streamlined to minimize the disruption of the velocity profile. Of course, as the polymer recombines after the spider leg, a weld line will form. Thus, the location of the spider support should be far enough from the die exit to enable the polymer to heal. The location of the die is generally adjustable relative to the pin, just as in the crosshead die. 

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