Minimum charge-recovery time control with parallel connected buck converters

Optimal-time control to minimise a converter’s recovery time has thus far been reported only for single power module converters. This paper adapts the optimal-time control problem and applies it to converters based on multiple power modules. Additionally, a novel minimum charge-recovery time control is also proposed for the multiple power module converter which produces a recovery time shorter than that in the optimal-time control. A 20 W converter is used to demonstrate the improved characteristics under primary regions of operation. Results show that the transient recovery time during a load step change is improved by 75% compared to traditional optimal time control

Sensors based on polymer modified electrodes

This paper will review the recent results that we have obtained using novel ruthenium-containing polymers, and on the further studies on the incorporation of proteins into polymeric matrices

Hybrid stars with the color dielectric and the MIT bag models

We study the hadron-quark phase transition in the interior of neutron stars (NS). For the hadronic sector, we use a microscopic equation of state (EOS) involving nucleons and hyperons derived within the Brueckner-Bethe-Goldstone many-body theory, with realistic two-body and three-body forces. For the description of quark matter, we employ both the MIT bag model with a density dependent bag constant, and the color dielectric model. We calculate the structure of NS interiors with the EOS comprising both phases, and we find that the NS maximum masses are never larger than 1.7 solar masses, no matter the model chosen for describing the pure quark phase.Comment: 11 pages, 5 figures, submitted to Phys. Rev.

Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection

Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans

Multi-stage LLC resonant converters designed for wide output voltage ranges

The paper describes a novel multi-stage LLC resonant converter topology for facilitating wide output voltage ranges. This is achieved by combining the gain range of a capacitor-diode clamped LLC resonant converter with that of a traditional LLC resonant converter. A prototype converter is designed and commissioned to illustrate the design procedure and demonstrate resulting operational characteristics. Experimental results are used to show operational characteristics of the proposed converter