S-duct inlet design and experimentation for small turbojet applications: Final report, APOP Black Team

This report outlines the process of testing an S-duct inlet for a JetCat P100-RX engine that satisfies the requirements of the 2020-2021 APOP design challenge, as well as the data that accompanied this testing. Through the use of a moment arm test stand, the data for thrust could be quickly tested for. Experimental results for pressure recovery were evaluated utilizing a static pressure ring and Kiel probes for total pressure measurement. The data was then processed and reported in the form seen in this report. Although the design is likely to change, the first iteration showed promising results, with a thrust difference of 0.1% and a pressure recovery value of 99.57%. The pressure recovery can be directly compared to the CFD results that showed a pressure recovery value of about 99.8% at full rpm. In addition, the SFC value only increased by about 1% when the inlet was installed. After these results varied so little, an inlet with a smaller build volume was created to take advantage of this difference. However, the newer iteration was not able to be tested because of technical issues associated with the engine and testing equipment. It is assumed that this inlet would have produced results comparable to the CFD results, which showed a pressure recovery of 99.3%. One final iteration was completed by reducing the axial length by half an inch. The overall recovery was seen to be 99.09% in this iteration. The team saw a 0.23% frictional loss from the first iteration's experimental testing, and they do not expect that result to increase substantially; this iteration is deemed very likely to succeed. The team is satisfied with the promising recovery results, especially when compared to the small model volume. Further experimental testing is recommended as well as continued iteration

The Expectation Monad in Quantum Foundations

The expectation monad is introduced abstractly via two composable adjunctions, but concretely captures measures. It turns out to sit in between known monads: on the one hand the distribution and ultrafilter monad, and on the other hand the continuation monad. This expectation monad is used in two probabilistic analogues of fundamental results of Manes and Gelfand for the ultrafilter monad: algebras of the expectation monad are convex compact Hausdorff spaces, and are dually equivalent to so-called Banach effect algebras. These structures capture states and effects in quantum foundations, and also the duality between them. Moreover, the approach leads to a new re-formulation of Gleason's theorem, expressing that effects on a Hilbert space are free effect modules on projections, obtained via tensoring with the unit interval.Comment: In Proceedings QPL 2011, arXiv:1210.029

Transcriptome profiling defines a novel regulon modulated by the LysR-type transcriptional regulator MexT in Pseudomonas aeruginosa

The LysR-family regulator MexT modulates the expression of the MexEF-OprN efflux system in the human pathogen Pseudomonas aeruginosa. Recently, we demonstrated that MexT regulates certain virulence phenotypes, including the type-three secretion system and early attachment independent of its role in regulating MexEF-OprN. In this study, transcriptome profiling was utilized to investigate the global nature of MexT regulation in P. aeruginosa PAO1 and an isogenic mexEF mutant. Twelve genes of unknown function were highly induced by overexpressing MexT independent of MexEF-OprN. A well-conserved DNA motif was identified in the upstream regulatory region of nine of these genes and upstream of mexE. Reporter fusion analysis demonstrated that the expression of the genes was significantly induced by MexT in P. aeruginosa and a heterogenous Escherichia coli strain and that the conserved sequence was required for this induction. The conserved DNA motif was further characterized as the MexT binding site by site-directed mutagenesis and electrophoretic mobility shift assays. Genes containing this conserved regulatory sequence were identified across other Pseudomonas species, and their expression was activated by MexT. Thus, a novel regulon directly modulated by MexT, that includes but is independent of mexEF-oprN, has been identified

X-ray Polarization of the Eastern Lobe of SS 433

How astrophysical systems translate the kinetic energy of bulk motion into the acceleration of particles to very high energies is a pressing question. SS 433 is a microquasar that emits TeV gamma-rays indicating the presence of high-energy particles. A region of hard X-ray emission in the eastern lobe of SS 433 was recently identified as an acceleration site. We observed this region with the Imaging X-ray Polarimetry Explorer and measured a polarization degree in the range 38% to 77%. The high polarization degree indicates the magnetic field has a well ordered component if the X-rays are due to synchrotron emission. The polarization angle is in the range -12 to +10 degrees (east of north) which indicates that the magnetic field is parallel to the jet. Magnetic fields parallel to the bulk flow have also been found in supernova remnants and the jets of powerful radio galaxies. This may be caused by interaction of the flow with the ambient medium.Comment: 8 pages, accepted in the Astrophysical Journal Letter