Taguchi‐based robust design for minimising torque ripple in 6‐slot/2‐pole modular high‐speed permanent magnet motor with manufacturing tolerances

A Taguchi-based robust design strategy is proposed to minimise the torque ripple of a 6-slot/2-pole modular high-speed permanent magnet motor in mass production, accounting for manufacturing tolerances of split gap (Δg), misalignment (Δm), and offset angle (Δα). Firstly, the effects and interactions of manufacturing tolerances are calculated, indicating that Δg has the highest effect followed by Δm, positive Δg and negative Δm have a strengthening effect, and Δα has no effect, and subsequently, the worst-case scenario of manufacturing tolerances with the highest torque ripple is obtained. Afterwards, tooth circumferential positions are optimised for minimising torque ripple without jeopardising average torque, considering the tradeoff between the cases without manufacturing tolerance and with the worst-case scenario of manufacturing tolerances. As will be demonstrated, torque ripples are reduced significantly, that is, they are particularly reduced by 40% in the worst-case scenario. Under hypothetical 100 sets manufacturing tolerances as Gauss distributions, the optimised machines have significantly reduced torque ripples (maximum and average reductions are 33% and 16%, respectively) with more concentrated distribution. The correctness of the methods is verified by experimental validation

Effects of Shielding Adenoviral Vectors with Polyethylene Glycol on Vector-Specific and Vaccine-Mediated Immune Responses

Many individuals have been previously exposed to human adenovirus serotype 5 (Ad5). This prior immunity has long been known to hinder its use for gene therapy and as a gene-based vaccine. Given these immunogenicity problems, we have tested whether polyethylene glycol (PEG) can blunt immune effects against Ad5 during systemic and mucosal vaccination. Ad5 vectors were covalently modified with 5-, 20-, and 35-kDa linear PEG polymers and evaluated for their ability to produce immune responses against transgene antigen prod- ucts and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by the intramuscular or intranasal route. In contrast, PEGylated vectors generally appear better at boosting antibody responses in Ad-immune animals. Displaying either glucose or galactose on PEG mediated increased transduction and antibody responses by the intranasal, but not the intramuscular, route. In naive animals, PEGylated vectors generated T cell responses that were equal to or better than those by unmodified Ad. Priming by PEGylated vectors generally enabled better subsequent T cell responses after boost. Priming and boosting by PEGylated vectors produced T cell responses after boost that were equal to or higher than those produced by unmodified vectors. These data indicate that PEGylation can enable more effective application of Ad5 and perhaps other Ad serotype vaccines during prime–boost vaccination

Palaeozoic polymetamorphism in the North Qinling orogenic belt, Central China: Insights from petrology and in situ titanite and zircon U-Pb geochronology

The Qinling orogenic belt experienced multiple phases of orogenesis during the Palaeozoic. Unraveling the timing and P- T conditions of these events is the key to understanding the convergence processes between the South China and the North China Blocks. The Songshugou Complex, located in the southern part of the North Qinling orogenic belt, has registered multistage metamorphism in Palaeozoic, and thus potentially provides insights into the tectonic evolution of the Qinling orogenic belt. In this study, three metabasic rocks (a garnet pyroxenite, a garnet amphibolite and a gneissic amphibolite) from the Songshugou Complex were selected for petrological study and zircon and titanite U-Pb dating. Our results show that the metabasic rocks experienced three metamorphic events during the Palaeozoic. The first metamorphic event (M1) is characterized by high pressure conditions. Two zircon grains in equilibrium with garnet and in absence of plagioclase were recognized from the garnet pyroxenite sample. They yielded Ti-in-zircon temperatures of 660-851. °C at ~12.0. kbar and a weighted mean age of 498 ± 15. Ma, providing the constraints on the temperature and timing of prograde or peak metamorphism (M1-1). Zircons that are inequilibrium with garnet from the garnet pyroxenite and the garnet amphibolite gave U-Pb ages of 494 ± 9. Ma and 484 ± 4. Ma, and Ti-in-zircon temperatures of 793 ± 33. °C and 738 ± 18. °C, respectively. Thus, these zircons were formed on the retrograde amphibolite-facies conditions at ~8.0. kbar (M1-2). Titanite inclusions were found in actinolite cores of zoned amphibole from the garnet amphibolite. They yielded a U-Pb age of ~470. Ma and Zr-in-titanite temperature of 676 ± 23. °C at pressure of ~7.0. kbar, suggesting that the amphibolite-facies retrogression perhaps persisted to ~470. Ma.Weakly zoned zircons from the garnet amphibolite and inclusion-free titanites from the garnet pyroxenite gave consistent U-Pb ages of 418 ± 5. Ma and 423 ± 10. Ma, and Ti-in-zircon temperature of 742 ± 26. °C and Zr-in-titanite temperature of 764 ± 18. °C at ~7.0. kbar, respectively. It is suggested that a heating event (M2) is registered by a subsequent phase of amphibolite-facies metamorphism. The ilmenite-bearing titanite crystals from the garnet pyroxenite yielded a U-Pb age of 352 ± 4. Ma, recording a late thermal event (M3).On the basis of combined petrological and geochronological results, we propose a revised tectonic model for the North Qinling orogeny in Palaeozoic. The high pressure granulites were formed by the northward subduction of the Shangdan oceanic slab and the arc-continent collision at ca. 500. Ma. Their exhumation happened at ca. 494-484. Ma as a result of slab breakoff. Subsequent amphibolite-facies metamorphism dated at ca. 440-420. Ma are coeval with the widespread magmatism in the North Qinling Terrane, which are likely caused by the reinitiation northward-subducted of Shangdan oceanic slab. At ca. 350. Ma, the North Qinling Terrane was likely affected by another thermal overprinting event. © 2014 Elsevier Ltd