Punching device

After the yarn is drawn, it is fibrillated. A large number of devices have been invented for fibrillating tapes in-line to give them a more fiber-like character. In various processes, the tapes are rolled, twisted, brushed, pulled, treated with air jets, subjected to ultrasonics, or contacted with rotating rolls that have cutting or punching devices on their periphery. The most prevalent method is that which uses rotating rolls. This method is simple, easy to... 

Fig. 3.17. Dimensions of the test specimen for the Notched Constant Tensile Load test (NCTL test). The test specimen is punched from the geomembrane by a suitable punching device. In a notching device (notcher) the specimen is notched with a razor blade in such a way that the notch depth is 20 % of the medium thickness of the geomembranes...

These ahoys are used as fuses, sprinkler system ahoys, foundry pattern ahoys, molds, dies, punches, cores, and mandrels where the low melting ahoy is often melted out of a mold. The ahoys are also used as solders, for the repHcation of human body parts (see Prosthetic devices), and as filler for tube bending. Lead—iadium ahoys are often used to joia metals to glass. 

The simplest way to identify a specimen is to mark it with letters or numbers applied by stamping with a stencil or number punch. There is, of course, always the danger that the identification marks will be obliterated by corrosion. To guard against this, the several specimens in a test should be identified further by a record of their positions relative to each other or to their supporting device. Before specimens are taken from test their identity should be established in this manner unless inspection has already shown that the identification marks have been preserved. 

The simplest adequate sampling device should be used. Where the contaminant Is believed to be on the surface, a soil punch or trowel may be used. If the contaminant Is soluble or Is expected to be located more than a meter below the surface, a truck mounted core sampler such as a split spoon sampler should be used. 

Working on experimental data at Edgewood drew me relentlessly into a deepening vortex of mathematics and other abstract domains, such as electronic circuits. I would often visit the Biostatistics Office and talk to John Atkinson about his LGP-30 computer, and how I could learn to use it. It was a monstrous device, one end taking in long ribbons of paper punched with holes that told it what to do and the other end typing answers without fingers on another role of paper, like the tapes that activate a player piano. 

Since in-house facilities for handling a large volume of samples for routine analysis were not available, the analytical work was contracted out to three commercial laboratories. We will refer to them as Laboratories A, B, and C. The contractors were selected on the basis of qualification tests which were intended to serve also for interlaboratory calibration. The results were reported to NRDL as d.p.m. or equivalent 285U thermal-neutron fissions at detonation time. All of the radiochemical data obtained from the laboratories are reported in Ref. 5. These values were punched on cards and converted by computer to equivalent fissions of the device, based on mass-chain yield values supplied by the weapons laboratories. At the same time, the calibration factors derived from qualification-test analyses were applied. Values of the ratios, 95, were formed. All of the ratios for a given nuclide i were then selected along with the corresponding values of r89t95, and the data points were fitted... 

The grade determines whether the mica can be used in high technology elecironic instruments, e.g.. computer-aided tomography (CATl scan, or in low technology devices, e.g.. a toaster. Many types of insulators, as well as the base for electronic circuits, are formed from the high quality sheets of mica by a punch pressing operation. 

FIGURE 2.12 Fabrication procedure of a PDMS chip (a) silicon master wafer with positive surface relief, (b) pre-mixed solution of Sylgard 184 and its curing agent poured over the master, (c) cured PDMS slab peeled from the master wafer, (d) PDMS slab punched with reservoir holes, and (e) ready-to-use device sealed with another slab of PDMS [159]. Reprinted with permission from the American Chemical Society. 

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