Quality, flight

In commercial extruders, additional zones may be included to improve the quality of the output. For example there may be a mixing zone consisting of screw flights of reduced or reversed pitch. The purpose of this zone is to ensure uniformity of the melt and it is sited in the metering section. Fig. 4.4 shows some designs of mixing sections in extruder screws. 

ToF analysers are able to provide simultaneous detection of all masses of the same polarity. In principle, the mass range is not limited. Time-of-flight mass analysis is more than an alternative method of mass dispersion it has several special qualities which makes it particularly well suited for applications in a number of important areas of mass spectrometry. These qualities are fast response time, compatibility with pulsed ionisation events (producing a complete spectrum for each event) ability to produce a snapshot of the contents of the source volume on the millisecond time-scale ability to produce thousands of spectra per second and the high fraction of the mass analysis cycle during which sample ions can be generated or collected. 

PAGE Phe Pro PSD QC Q-ToF Q-ToF-LC-MS-MS polyacrylamide gel electrophoresis phenylalanine proline post-source decay quality control quadrupole time-of-flight mass analyser quadrupole time-of-flight mass analyser in combination with (high performance) liquid chromatography and tandem mass... 

This case study clearly shows that a worn screw will cause the discharge temperature to increase due to material flow over the flights and will decrease the heat transfer coefficient, limiting the transfer of energy through the barrel wall. With the restored flight clearance, the process was able to increase the rate by about 35%, and the quality of the product was improved. 

With the advent of electrospray mass spectrometry and the re-emergence of time of flight mass spectrometry, the technique will be of major use in the quality control of therapeutic antibodies and peptides. 

As with neutron powder methods, both monochromatic and time-of-flight (Laue) techniques have been used for single-crystal neutron studies. Such studies are much less numerous, however, as a result of the difficulty of compressing suitably sized (>1 mm ) single-crystal sample to the required pressure while maintaining the crystal quality. The piston cylinder cell design of Me Whan and others [128] has been used at the ILL reactor source for a number of neutron structural studies to... 

Zel J.A. Man ford, "Development of a Weld Quality Monitor , NASA Goddard Space Flight Center N69-33800, Aug 1969, llpp 5) D.V. Lindh G-M. Peshak, "The Influence of Weld Defects and Repair Welds on Performance , Boeing Co, AD-697 243, 1969, 66 pp 6)... 

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