Aerodynamic investigations of ventilated brake discs.

The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometries, rotated in free air, were measured using a five-hole pressure probe and a hot-wire anemometry system. The principal measurements were taken using two-component hot-wire techniques and were used to determine mean and unsteady flow characteristics at the exit of the brake rotors. Using phase-locked data processing, it was possible to reveal the spatial and temporal flow variation within individual rotor passages. The effects of disc geometry and rotational speed on the mean flow, passage turbulence intensity, and mass flow were determined. The rotor exit jet and wake flow were clearly observed as characterized by the passage geometry as well as definite regions of high and low turbulence. The aerodynamic flow characteristics were found to be reasonably independent of rotational speed but highly dependent upon rotor geometry

Installed performance assessment of a boundary layer ingesting distributed propulsion system at design point

Boundary layer ingesting systems have been proposed as a concept with great potential for reducing the fuel consumption of conventional propulsion systems and the overall drag of an aircraft. These studies have indicated that if the aerodynamic and efficiency losses were minimised, the propulsion system demonstrated substantial power consumption benefits in comparison to equivalent propulsion systems operating in free stream flow. Previously assessed analytical methods for BLI simulation have been from an uninstalled perspective. This research will present the formulation of an rapid analytical method for preliminary design studies which evaluates the installed performance of a boundary layer ingesting system. The method uses boundary layer theory and one dimensional gas dynamics to assess the performance of an integrated system. The method was applied to a case study of the distributed propulsor array of a blended wing body aircraft. There was particular focus on assessment how local flow characteristics influence the performance of individual propulsors and the propulsion system as a whole. The application of the model show that the spanwise flow variation has a significant impact on the performance of the array as a whole. A clear optimum design point is identified which minimises the power consumption for an array with a fixed configuration and net propulsive force requirement. In addition, the sensitivity of the system to distortion related losses is determined and a point is identi ed where a conventional free-stream propulsor is the lower power option. Power saving coefficient for the configurations considered is estimated to lie in the region of 15%

Thin-Film Trilayer Manganate Junctions

Spin-dependent conductance across a manganate-barrier-manganate junction has recently been demonstrated. The junction is a La$_{0.67}$Sr$_{0.33}$MnO$_3$% -SrTiO$_3$-La$_{0.67}$ Sr$_{0.33}$MnO$_3$ trilayer device supporting current-perpendicular transport. Large magnetoresistance of up to a factor of five change was observed in these junctions at 4.2K in a relatively low field of the order of 100 Oe. Temperature and bias dependent studies revealed a complex junction interface structure whose materials physics has yet to be understood.Comment: 20 pages, 14 figures. To appear in Phil. Trans. R. Soc. Lond. A vol.356 (1998

Induced magnetization in La0.7_{0.7}Sr0.3_{0.3}MnO3_3/BiFeO3_3 superlattices

Using polarized neutron reflectometry (PNR), we observe an induced magnetization of 75$\pm$ 25 kA/m at 10 K in a La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO)/BiFeO$_3$ superlattice extending from the interface through several atomic layers of the BiFeO$_3$ (BFO). The induced magnetization in BFO is explained by density functional theory, where the size of bandgap of BFO plays an important role. Considering a classical exchange field between the LSMO and BFO layers, we further show that magnetization is expected to extend throughout the BFO, which provides a theoretical explanation for the results of the neutron scattering experiment.Comment: 5 pages, 4 figures, with Supplemental Materials. To appear in Physical Review Letter

The Cannabinoid Use in Progressive Inflammatory brain Disease (CUPID) trial: a randomised double-blind placebo-controlled parallel-group multicentre trial and economic evaluation of cannabinoids to slow progression in multiple sclerosis.

This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.The Cannabinoid Use in Progressive Inflammatory brain Disease (CUPID) trial aimed to determine whether or not oral Δ(9)-tetrahydrocannabinol (Δ(9)-THC) slowed the course of progressive multiple sclerosis (MS); evaluate safety of cannabinoid administration; and, improve methods for testing treatments in progressive MS.The National Institute for Health Research Health Technology Assessment programmeMedical Research Council Efficacy and Mechanism Evaluation programmeMultiple Sclerosis SocietyMultiple Sclerosis Trus

Effective Vortex Pinning in MgB2 thin films

We discuss pinning properties of MgB2 thin films grown by pulsed-laser deposition (PLD) and by electron-beam (EB) evaporation. Two mechanisms are identified that contribute most effectively to the pinning of vortices in randomly oriented films. The EB process produces low defected crystallites with small grain size providing enhanced pinning at grain boundaries without degradation of Tc. The PLD process produces films with structural disorder on a scale less that the coherence length that further improves pinning, but also depresses Tc

Strongly Enhanced Current Densities in Superconducting Coated Conductors of YBa2Cu3O7-x + BaZrO3

There are numerous potential applications for superconducting tapes, based on YBa2Cu3O7-x (YBCO) films coated onto metallic substrates. A long established goal of more than 15 years has been to understand the magnetic flux pinning mechanisms which allow films to maintain high current densities out to high magnetic fields. In fact, films carry 1-2 orders of magnitude higher current densities than any other form of the material. For this reason, the idea of further improving pinning has received little attention. Now that commercialisation of conductors is much closer, for both better performance and lower fabrication costs, an important goal is to achieve enhanced pinning in a practical way. In this work, we demonstrate a simple and industrially scaleable route which yields a 1.5 to 5-fold improvement in the in-field current densities of already-high-quality conductors

Research Update: Atmospheric pressure spatial atomic layer deposition of ZnO thin films: Reactors, doping, and devices

Atmospheric pressure spatial atomic layer deposition (AP-SALD) has recently emerged as an appealing technique for rapidly producing high quality oxides. Here, we focus on the use of AP-SALD to deposit functional ZnO thin films, particularly on the reactors used, the film properties, and the dopants that have been studied. We highlight how these films are advantageous for the performance of solar cells, organometal halide perovskite light emitting diodes, and thin-film transistors. Future AP-SALD technology will enable the commercial processing of thin films over large areas on a sheet-to-sheet and roll-to-roll basis, with new reactor designs emerging for flexible plastic and paper electronics.The authors acknowledge the support of the Rutherford Foundation of New Zealand and the Cambridge Commonwealth, European and International Trusts, and the ERC Advanced Investigator Grant, Novox, ERC-2009-adG247276. DMR acknowledges Marie Curie Actions (FP7/2007-2013, Grant Agreement Nos. 219332 and 631111), and the Ramon y Cajal 2011 programme from the Spanish MICINN and the European Social Fund, and the Comissionat per a Universitats I Recerca (CUR) del DIUE de la Generalitat de Catalunya, Spain.This is the final published version of the article. It was originally published in APL Materials (Hoye RLZ, Muñoz-Rojas D, Nelson SF, Illiberi A, Poodt P, Roozeboom F, MacManus-Driscoll JL, APL Materials, 2015, 3, 040701, doi:10.1063/1.4916525). The final version is available at http://dx.doi.org/10.1063/1.491652

From warfare to welfare: veterans, military charities and the blurred spatiality of post-service welfare in the United Kingdom

The military offers a form of welfare-for-work but when personnel leave they lose this safety net, a loss exacerbated by the rollback neoliberalism of the contemporary welfare state. Increasingly the third sector has stepped in to address veterans’ welfare needs through operating within and across military/civilian and state/market/community spaces and cultures. In this paper we use both veterans’ and military charities’ experiences to analyse the complex politics that govern the liminal boundary zone of post-military welfare. Through exploring ‘crossing’ and ‘bridging’ we conceptualise military charities as ‘boundary subjects’, active yet dependent on the continuation of the civilian-military binary, and argue that the latter is better understood as a multidirectional, multiscalar and contextual continuum. Post-military welfare emerges as a competitive, confused and confusing assemblage that needs to be made more navigable in order to better support the ‘heroic poor’

Interface-Coupled BiFeO<inf>3</inf>/BiMnO<inf>3</inf> Superlattices with Magnetic Transition Temperature up to 410 K

This research was funded by the Engineering and Physical Sciences Research Council, (EP/P50385X/1), the European Research Council (ERC-2009-AdG 247276 NOVOX). The work at Texas A&M was funded by the U.S. National Science Foundation (DMR-1401266). The work at Los Alamos was supported by the U.S. Department of Energy through the LANL/LDRD program and was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Basic Energy Sciences user facility. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/admi.20150059