28,464 research outputs found
Integrated airframe propulsion control
Perturbation equations which describe flight dynamics and engine operation about a given operating point are combined to form an integrated aircraft/propulsion system model. Included in the model are the dependence of aerodynamic coefficients upon atmospheric variables along with the dependence of engine variables upon flight condition and inlet performance. An off-design engine performance model is used to identify interaction parameters in the model. Inclusion of subsystem interaction effects introduces coupling between flight and propulsion variables. To analyze interaction effects on control, consideration is first given to control requirements for separate flight and engine models. For the separate airframe model, feedback control provides substantial improvement in short period damping. For the integrated system, feedback control compensates for the coupling present in the model and provides good overall system stability. However, this feedback control law involves many non-zero gains. Analysis of suboptimal control strategies indicates that performance of the closed loop integrated system can be maintained with a feedback matrix in which the number of non-zero gains is small relative to the number of components in the feedback matrix
The incidence and position of melanocytic nevi for the purposes of forensic image comparison
Expert witness opinion based on the comparison of images has been accepted by UK courts as admissible evidence in relation to issues of identity. Within images of the hand are a multiplicity of anatomical features of different aetiology, incidence and distribution patterns and this includes melanocytic nevi, referred to more colloquially as moles and/or birthmarks. The hand is not a common place for these isolated features to develop and so their presence in this anatomical region has the potential to be useful for issues of identity. The results of this study show that approximately 9 % of individuals in a sample of 476 hands, displayed at least one nevus on the back of their hand and, contrary to the literature, the incidence was found to be greater in females (15 % of female cohort) than males (7 % of male cohort). Almost a third of all nevi identified on the dorsum of the hand were abnormal or dysplastic. The most frequent location for these aggregations of melanocytes was in the central region of the dorsum of the hand or at the base of the index finger. The relevance of nevi identified in the image of a perpetrator’s hand and also on that of a suspect/accused is discussed in relation to the issue of whether the images have originated from the same individual
Adult literacy and liberal-progressive pedagogy: Australian contexts
© 2018 Association for Research in Post-Compulsory Education (ARPCE). This article explores adult literacy pedagogy in the Australian vocational education and training (VET) sector which has long provided most adult literacy programmes. We draw on semi-structured interviews with a small group of eight teachers undertaken in 2005 as part of a project on the social capital outcomes of adult literacy programmes. Through highlighting various elements of student-centred pedagogy, the aim is to demonstrate what is commonly referred to as liberal-progressive pedagogy. We discuss how some educators in this pedagogical tradition have incorporated critical literacy, while others have critiqued it as largely accommodating the status quo. Since the mid-1990s however, the field of adult literacy in VET has been increasingly colonised by neo-liberal ideology which sees literacy equated with human capital. Consequently, adult literacy pedagogy in VET in recent times fits within an industry-dominated, competency-based and nationally accredited VET system in which, we argue, the curriculum provides few spaces for liberal-progressive pedagogy. As teachers express their concerns at the possible demise of liberal-progressive pedagogy in adult literacy in VET, it is timely to reflect on its key elements and its value for social justice
A new nickel-base wrought superalloy for applications up to 1033 K (1400 F)
Alloy was melted from high purity raw materials and cast ingots extruded at 1422 K. Material was hot rolled to 0.013 m diameter bar stock. Partial solution heat-treatment followed by aging produced structure of fine gamma prime precipitate reinforcing gamma matrix containing coarser blocky gamma prime particles. Alloy can be processed by powder metallurgy
Molecular clouds in the centers of galaxies: Constraints from HCN and CO-13 line emission
We have searched for HCN J=1-0 line emission in the centers of 12 galaxies and have detected it in 10 of them. We have obtained complementary data on J=1-0 and 2-1 transitions of CO-12 and CO-13 in these systems. The ratio of integrated intensities, I(CO 1-0)/I(HCN 1-0) = 25 +/- 11 for this sample. We find that HCN emission of this strength can be produced under conditions of subthermal excitation. In combination with the line ratios in CO and CO-13, HCN puts constraints on the mean conditions of molecular clouds and on the mix of cloud types within the projected beam
New nickel-base wrought superalloy with applications up to 1253 K (1800 F)
Alloy possesses combination of high tensile strength at low and intermediate temperatures to 1033 K with good rupture strength at high temperatures to 1255 K. Alloy has promise for turbine disk application in future gas turbine engines and for wrought integrally bladed turbine wheel; thickness and weight of disk portion of wheel could be reduced
Parity Effect in a Small Superconducting Particle
Matveev and Larkin calculated the parity effect on the ground state energy of
a small superconducting particle in the regimes where the mean level spacing is
either large or small compared to the bulk gap. We perform a numerical
calculation which extends their results into the intermediate regime, where the
level spacing is of the same order as the bulk gap.Comment: 6 LaTeX pages, including 2 EPS figures; corrected reference and
spellin
Impact Crater Geometries Provide Evidence for Ice-rich Layers at Low Latitudes on Mars
The impact cratering record documents the history of resurfacing events on Mars. The morphology and distribution of layered (rampart) ejecta blankets provide insights into the presence of volatiles in the upper crust [1-4]. The physical properties of the crust and history of water have been revealed through recent quantitative studies of the geometry of Martian craters [5-91. Here, we present the results from a study focused on impact craters in Utopia Planitia and the Elysium Mons province to infer the history and properties of resurfacing episodes
Can Memory Assessment Services (MAS) in England be categorized? A national survey.
: The effectiveness and efficiency of memory assessment services (MASs) is unknown. Our aim was to determine if a typology can be constructed, based on shared structural and process characteristics, as a basis for a non-randomized evaluation of their effectiveness and cost-effectiveness. : Survey of random sample of 73 MASs in 2015; comparison of characteristics and investigation of inter-correlation. : It was not possible to group characteristics to form the basis of a typology of MASs. However, there was considerable variation in staff numbers (20-fold), new patients per whole-time equivalent (WTE) staff (20-fold), skill mix and the nurse:doctor ratio (1-10). The operational performance also varied: first appointments (50-120 minutes); time for first follow-up (2-12 weeks); frequency of follow-up in first year (1-5). These differences were not associated with the number of new patients per WTE staff or the accreditation status of the MAS. Post diagnosis, all MASs provided pharmacological treatment but the availability of non-pharmacological support varied, with half providing none or only one intervention while others providing four or more. : In the absence of any clear typology, evaluation of MASs will need to focus on the impact of individual structural and process characteristics on outcomes.<br/
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