Stitching template

Preform molds can be simple draping aids or complex stitching templates, depending on the application. A preform mold has to perform different functions ... 

Depending on the application, different requirements are set for the preform molds. If a preform is needed that is mainly manufactured by hand, a stitching template or similar aids can be used in the simplest case. For complex but smaller components, an alternative preform mold is recommended that is more specialized to the usage of automated technologies. 

FIGURE 1.231 Stitching template for stitching integration of load input elements 1.8.4.3 Molds for Vacuum Assisted Processes... 

The second problem occurs as the replication fork opens up. The synthesis of one strand of new DNA can proceed without difficulty this is the strand that the polymerase makes as it reads the template in a 3 - 5 direction, making a new strand in a 5 - -3 orientation, as all polymerases do. But how to synthesize the second strand If done directly, the polymerase would have to read the template in a 5 - 3 direction and thus synthesize the new strand in a 3 - 5 direction. Although there is no theoretical reason why this could not occur, no known polymerase synthesizes in a 3 - -5 direction. Instead, after a stretch of DNA has been opened up, an RNA primer is made near the fork and DNA synthesis proceeds backward, away from the replication fork, in a 5 - 3 direction. Further synthesis on this lagging strand must wait until the replication fork opens up another stretch of DNA another RNA primer must then be made, and DNA synthesis proceeds backward toward the previously synthesized fragment. The RNA primers must then be removed, the gaps filled in with DNA, and the ends of the DNA pieces stitched together. This requires several more enzymes. 

DNA polymerases work by stitching together two nucleotides, one at the 3 end of a DNA chain and the other a deoxynucleic acid triphosphate. The two are held in position near each other by hydrogen bonding to the template DNA chain and are joined by reaction of the first phosphate of the triphosphate with the OH of the saccharide ring of the other base, releasing diphosphate. Mg ions separated by about 390 pm are bound on each side of the phosphorus in the transition state, as in Figure 16-23. 

A run-stitch or profile-stitch operation can be done using a jig (Carr and Latham, 1999) or template (Solinger, 1988). It consists of two layers of rigid material such as aluminium or acrylic joined together by a hinge. A slot is cut out of both layers of material conforming to the exact shape and size of component to be sewn. The... 

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