Modelling of cryogenic cooling system design concepts for superconducting aircraft propulsion

Distributed propulsion concepts are promising in terms of improved fuel burn, better aerodynamic performance, and greater control. Superconducting networks are being considered for their superior power density and efficiency. This study discusses the design of cryogenic cooling systems which are essential for normal operation of superconducting materials. This research project has identified six key requirements such as maintain temperature and low weight, with two critical components that dramatically affect mass identified as the heat exchanger and compressors. Qualitatively, the most viable concept for cryocooling was found to be the reverse-Brayton cycle (RBC) for its superior reliability and flexibility. Single- and two-stage reverse-Brayton systems were modelled, highlighting that double stage concepts are preferable in specific mass and future development terms in all cases except when using liquid hydrogen as the heat sink. Finally, the component-level design space was considered with the most critical components affecting mass being identified as the reverse-Brayton compressor and turbine

Quality function deployment and sensitivity analysis of requirements for future aircraft propulsion cryogenic cooling systems

A number of novel future airframe and propulsion concepts are considered in order to meet aviation targets set by various aviation regulatory bodies including NASA and the Advisory Council for Aeronautics Research in Europe (ACARE). The current NASA concept for long-range civil aircraft is the Blended-Wing Body (BWB) aircraft, coupled with turbo-electric distributed propulsion (TeDP), to enable a host of efficiency benefits over current designs. NASA has identified superconducting technology as a key enabler to deliver this airframe. Superconductors need to be cooled to cryogenic temperatures for normal operation. Using a sensitivity matrix, it was found that the Exchange Heat and Transport/Pump Cryogen functions are the most sensitive to input variation. The failure modes and effects analysis performed on the functional model show that the detection functions are critical during component failure. Quality Function Deployment (QFD) analysis shows the Exchange Heat and Transport/Pump Cryogen functions are also critical

Infrared Non-detection of Fomalhaut b -- Implications for the Planet Interpretation

The nearby A4-type star Fomalhaut hosts a debris belt in the form of an eccentric ring, which is thought to be caused by dynamical influence from a giant planet companion. In 2008, a detection of a point-source inside the inner edge of the ring was reported and was interpreted as a direct image of the planet, named Fomalhaut b. The detection was made at ~600--800 nm, but no corresponding signatures were found in the near-infrared range, where the bulk emission of such a planet should be expected. Here we present deep observations of Fomalhaut with Spitzer/IRAC at 4.5 um, using a novel PSF subtraction technique based on ADI and LOCI, in order to substantially improve the Spitzer contrast at small separations. The results provide more than an order of magnitude improvement in the upper flux limit of Fomalhaut b and exclude the possibility that any flux from a giant planet surface contributes to the observed flux at visible wavelengths. This renders any direct connection between the observed light source and the dynamically inferred giant planet highly unlikely. We discuss several possible interpretations of the total body of observations of the Fomalhaut system, and find that the interpretation that best matches the available data for the observed source is scattered light from transient or semi-transient dust cloud.Comment: 12 pages, 4 figures, ApJ 747, 166. V2: updated acknowledgments and reference

Intra-Rater reliability of the Functional Movement Screen (FMS) amongst NHS Physiotherapists

Objectives: The primary aim of this study was to evaluate the intra-rater reliability of the FMS amongst a group of novice National Health Service (NHS) Physiotherapists. The secondary objective was to establish if Intra-rater reliability differed between non-specialist rotational Physiotherapists and Physiotherapists working within the musculoskeletal (MSk) setting. Design: Reliability Study. Method: Forty participants with no recent MSk injury were video recorded completing the 7 component FMS tests. Six NHS Physiotherapists with no previous experience using the FMS attended a 2 hour training programme delivered by a certified FMS practitioner. Raters then viewed and scored videos of the 40 participants completing the FMS. Results: The intra-rater reliability of FMS composite scores was Excellent (mean ICC of 0.91 (95% CI 0.81-0.96)). The non-specialist rotational Physiotherapist group demonstrated Good-Excellent intra-rater reliability (ICC 0.9; 95% CI 0.79-0.95). Specialist MSk Physiotherapists demonstrated Excellent intra-rater reliability (ICC 0.92; 95% CI 0.84-0.96). Intra-rater reliability of the 7 component tests of the FMS ranged from Poor-Excellent (KW 95% CI 0.11-0.98). Conclusion: Among novice NHS Physiotherapists, the FMS composite score demonstrated Excellent intra-rater reliability. MSk specialists were found to demonstrate a marginally superior level of intra-rater agreement compared to non-specialist rotational Physiotherapists; however this is likely to be negligible in a clinical context. Clinical specialism also appears to have little impact on the intra-rater reliability of FMS components with both groups of raters achieving a Poor-Excellent level of agreement. Keywords: Intra-rater, reliability, functional movement screen, FM

Fall armyworm (Spodoptera frugiperda Smith) feeding elicits differential defense responses in upland and lowland switchgrass

Switchgrass (Panicum virgatum L.) is a low input, high biomass perennial grass being developed for the bioenergy sector. Upland and lowland cultivars can differ in their responses to insect herbivory. Fall armyworm [FAW; Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae)] is a generalist pest of many plant species and can feed on switchgrass as well. Here, in two different trials, FAW larval mass were significantly reduced when fed on lowland cultivar Kanlow relative to larvae fed on upland cultivar Summer plants after 10 days. Hormone content of plants indicated elevated levels of the plant defense hormone jasmonic acid (JA) and its bioactive conjugate JA-Ile although significant differences were not observed. Conversely, the precursor to JA, 12-oxo-phytodienoic acid (OPDA) levels were significantly different between FAW fed Summer and Kanlow plants raising the possibility of differential signaling by OPDA in the two cultivars. Global transcriptome analysis revealed a stronger response in Kanlow plant relative to Summer plants. Among these changes were a preferential upregulation of several branches of terpenoid and phenylpropanoid biosynthesis in Kanlow plants suggesting that enhanced biosynthesis or accumulation of antifeedants could have negatively impacted FAW larval mass gain on Kanlow plants relative to Summer plants. A comparison of the switchgrass-FAW RNA-Seq dataset to those from maize-FAW and switchgrass-aphid interactions revealed that key components of plant responses to herbivory, including induction of JA biosynthesis, key transcription factors and JA-inducible genes were apparently conserved in switchgrass and maize. In addition, these data affirm earlier studies with FAW and aphids that the cultivar Kanlow can provide useful genetics for the breeding of switchgrass germplasm with improved insect resistance

Aboveground Herbivory Influences Belowground Defense Responses in Maize

The European corn borer (ECB; Ostrinia nubilalis) is an economically damaging insect pest of maize (Zea mays L.), an important cereal crop widely grown globally. Among inbred lines, the maize genotype Mp708 has shown resistance to diverse herbivorous insects, although several aspects of the defense mechanisms of Mp708 plants are yet to be explored. Here, the changes in root physiology arising from short-term feeding by ECB on the shoot tissues of Mp708 plants was evaluated directly using transcriptomics, and indirectly by monitoring changes in growth of western corn rootworm (WCR; Diabrotica virgifera virgifera) larvae. Mp708 defense responses negatively impacted both ECB and WCR larval weights, providing evidence for changes in root physiology in response to ECB feeding on shoot tissues. There was a significant downregulation of genes in the root tissues following short-term ECB feeding, including genes needed for direct defense (e.g., proteinase inhibitors and chitinases). Our transcriptomic analysis also revealed specific regulation of the genes involved in hormonal and metabolite pathways in the roots of Mp708 plants subjected to ECB herbivory. These data provide support for the long-distance signaling-mediated defense in Mp708 plants and suggest that altered metabolite profiles of roots in response to ECB feeding of shoots likely negatively impacted WCR growth

Fall armyworm (Spodoptera frugiperda Smith) feeding elicits differential defense responses in upland and lowland switchgrass

Switchgrass (Panicum virgatum L.) is a low input, high biomass perennial grass being developed for the bioenergy sector. Upland and lowland cultivars can differ in their responses to insect herbivory. Fall armyworm [FAW; Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae)] is a generalist pest of many plant species and can feed on switchgrass as well. Here, in two different trials, FAW larval mass were significantly reduced when fed on lowland cultivar Kanlow relative to larvae fed on upland cultivar Summer plants after 10 days. Hormone content of plants indicated elevated levels of the plant defense hormone jasmonic acid (JA) and its bioactive conjugate JA-Ile although significant differences were not observed. Conversely, the precursor to JA, 12-oxo-phytodienoic acid (OPDA) levels were significantly different between FAW fed Summer and Kanlow plants raising the possibility of differential signaling by OPDA in the two cultivars. Global transcriptome analysis revealed a stronger response in Kanlow plant relative to Summer plants. Among these changes were a preferential upregulation of several branches of terpenoid and phenylpropanoid biosynthesis in Kanlow plants suggesting that enhanced biosynthesis or accumulation of antifeedants could have negatively impacted FAW larval mass gain on Kanlow plants relative to Summer plants. A comparison of the switchgrass-FAW RNA-Seq dataset to those from maize-FAW and switchgrass-aphid interactions revealed that key components of plant responses to herbivory, including induction of JA biosynthesis, key transcription factors and JA-inducible genes were apparently conserved in switchgrass and maize. In addition, these data affirm earlier studies with FAW and aphids that the cultivar Kanlow can provide useful genetics for the breeding of switchgrass germplasm with improved insect resistance