Needle drives

Stoianovici, D., et al., Frictitm Transmission with Axial Loading and a Radiolucent Surgical Needle Drive, 1997, Jtduis Hc kins University (provisional patent application filed 17 February 1997). 

FIGURE 1.53 Multi- needle shut-off nozzles with grouped needle drive but individual nozzle heating [21]... 

Needle drives with pneumatic piston actuators that can be incorporated directly into the clamping plate of the mold have proven successful. Standardized designs, as shown in Figure 2.63, can be easily installed, and important functions such as radial compensation and needle adjustment are already integrated into the assembly. 

FIGURE 2.63 Pneumatic needle drive with needle guide and valve gate nozzle... 

FIGURE 2.64 Hydraulic needle drive, mounted on the hot runner manifold... 

The installation of electromagnetic systems into the mold is very simple and clearly more cost-effective than installing a conventional needle drive. No supply bore holes have to be drilled into the clamping plate. The control of the electromagnets is very... 

This dial indicator is fixed to the volute mounting adapter collar of the pump and the needle is on the shaft (Figure 14-21). The shaft should be moved radially by hand (see the arrows) up and down. Note the movement in the indicator. This is a check of the radial tolerance in the bearing. Some people use the word run out . Radial dellection causes misalignment of the rotating and stationary faces of the mechanical seal. This shortens the seal life by eausing drive pins and springs to wear and rub in relative motion. 

N 36.83%, OB to C02 -42.1% colorless needles from ether nip 38° d 1.243 at 49/4° RI 1.4616 at 48,6°. V sol in cold w, ale, chlf and benz less sol in eth and still less sol in petr eth. Can be prepd by nitrating n-methyl-urethane with abs nitric acid. The resulting soln of methyl nitrourethane is drowned in w, neutralized with Na carbonate, and extrd with eth to remove methyl nitrourethane. On passing ammonia gas thru the eth extract, a white ppt of the ammonium salt of methylnitramine is deposited and sepd by filtration. It is disd in ale and boiled to drive off the ammonia, and... 

One result is that needle sharing among injection drug users is now a major force driving the HIV/AIDS and hepatitis C epidemics in America. ... 

Taxol was the most triumphant new anticancer drug developed in the last few decades. It resulted from a drive to screen thousands of synthesized compounds and plant extracts, financed by the National Cancer Institute (Georg et al. 1994, Suffness 1995, Goodman and Walsh 2001). Taxol is extracted from the bark of the Pacific yew tree, or Taxus brevifoli, found in the Pacific Northwest, and has been proven effective against intractable breast and ovarian cancers. It is now produced by semi-synthetic methods from the needles of the common ornamental tree English Yew, or Taxus baccata. We will discuss taxol in greater detail in Chapter 2. 

The BTSP-pyridinium dichromate system has proved to be effective for generation of the oxodiperoxochromium complex 22 in dichloromethane. As the peroxo complex decomposed easily, the oxidant BTSP was added dropwise to the reaction mixture using a syringe drive. The BTSP was stable enough even upon contact with the metallic surface of the syringe needle when it was diluted with dichloromethane. Typical results for the conversion of alcohols into carbonyl compounds are summarized in Table 7. 

Crystals formed under small driving force conditions (see Section 3.2) in a dilute ambient phase, such as the vapor phase or solution phase, will generally exhibit polyhedral forms, irrespective of their size. Even crystals of micrometer size, such as clay minerals, show polyhedral forms. However, there are crystals that show elongated needle forms that resemble whiskers, coils, hollow tubes, and even ice cream cones (see Figs. 2.2 (a), (b)) others exhibit tree-like polycrystalline aggregates of dendrites (see Fig. 2.2 (c)). 

Surface voltage decay was measured with a Trek Model 341 high voltage electrostatic voltmeter (ESVM). The ESVM drives the potential of a probe body to the same potential as the film surface voltage. This device measures the voltage independent of distance within 5 mm of the film surface without causing current flow, which would modify the data. After poling, the corona needle was removed and the probe of the ESVM was placed 3 mm from the film surface. 

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