Euler Simulations of Pitching Delta Wing Aerodynamics within Wind Tunnel Constraints. Dept of Engineering technical report 0114

Euler simulations of a pitching delta wing within three wind tunnels (Square, 3x2, and 2x3 tunnels) have been performed. The solutions have been validated by comparing a farfield solution with experimental data. The steady solutions have shown that the presence of the wind tunnels promotes vortex breakdown, and that the side walls are the most influential. The presence of the side walls increases the suction on the surface of the wing, and shifts the vortex core inboards and upwards. The roof and floor have a lesser influence as was demonstrated by bringing the roof and floor closer to the wing surface (changing from the square tunnel to the 3x2 tunnel). It was concluded that the main effect causing the shift towards the apex of the breakdown location was an increase in the mean incidence of the wing. As with the steady solutions, the unsteady solutions have shown that the 2x3 tunnel varies the breakdown locations the most, in comparison to those from the farfield solution. The greatest divergence of the breakdown locations from those of the farfield solution occurs on the downstroke of the motion. This is due to the fact that the wing leaves a state of high tunnel interference going to a state of lower interference

Deconstructing Noncommutativity with a Giant Fuzzy Moose

We argue that the worldvolume theories of D-branes probing orbifolds with discrete torsion develop, in the large quiver limit, new non-commutative directions. This provides an explicit `deconstruction' of a wide class of noncommutative theories. This also provides insight into the physical meaning of discrete torsion and its relation to the T-dual B field. We demonstrate that the strict large quiver limit reproduces the matrix theory construction of higher-dimensional D-branes, and argue that finite `fuzzy moose' theories provide novel regularizations of non-commutative theories and explicit string theory realizations of gauge theories on fuzzy tori. We also comment briefly on the relation to NCOS, (2,0) and little string theories.Comment: 22 pages, 3 figures, typos caught and refs added; expanded interpretation of discrete torsio

Sources and contributions of wood smoke during winter in London: Assessing local and regional influences

Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions have been identified as a major cause of exceedances of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2:5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and KC were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Aethalometer-derived black carbon data were also apportioned into the contributions frombiomass burning and traffic and showed trends similar to those observed for EC. Mean wood smoke mass at the sites was estimated to range from 0.78 to 1.0 μgm-3 during the campaign in January–February 2012. Measurements on a 160m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and KC concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources

Removal and fate of endocrine disruptors chemicals under lab-scalepostreatment stage. Removal assessment using light, oxygen and microalgae

[EN] The aim of this study was to assess the effect of light, oxygen and microalgae on micropollutants removal. The studied micropollutants were 4-(1,1,3,3-tetramethylbutyl)phenol (OP), technical-nonylphenol (t-NP), 4-n-nonylphenol (4-NP), Bisphenol-A (BPA). In order to study the effect of the three variables on the micropollutants removal, a factorial design was developed. The experiments were carried out in four batch reactors which treated the effluent of an anaerobic membrane bioreactor. The gas chromatography mass spectrometry was used for the measurement of the micropollutants. The results showed that light, oxygen and microalgae affected differently to the degradation ratios of each micropollutant. The results showed that under aerated conditions removal ratios higher than 91% were achieved, whereas for non-aerated conditions the removal ratios were between 50% and 80%, except for 4-NP which achieved removal ratios close to 100%. Besides, mass balance showed that the degradation processes were more important than the sorption processes. (C) 2013 Elsevier Ltd. All rights reserved.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2011-28595-C02-01/02) jointly with the European Regional Development Fund (ERDF), The Government of the Region of Valencia (Generalitat Valenciana), within the research project "Application of Water Framework Directive 2000/60/EC on endocrine disruptors and priority substances in coastal areas in the Comunitat Valenciana" and by the Spanish Research Foundation (MINECO, project CTM2008-060809-C02-01/TECNO), within the research project "Feasibility of the SAnMBR technology to treat urban wastewater, and the technical and economic feasibility to industrial implementation" which are gratefully acknowledged.Abargues Llamas, MR.; Ferrer, J.; Bouzas Blanco, A.; Seco Torrecillas, A. (2013). Removal and fate of endocrine disruptors chemicals under lab-scalepostreatment stage. Removal assessment using light, oxygen and microalgae. Bioresource Technology. 149:142-148. https://doi.org/10.1016/j.biortech.2013.09.051S14214814

An electric field cell for performing in situ single-crystal synchrotron X-ray diffraction

With the recent increase in research into ferroelectric, anti-ferroelectric and piezoelectric materials, studying the solid-state properties in situ under applied electric fields is vital in understanding the underlying processes. Where this behaviour is the result of atomic displacements, crystallographic insight has an important role. This work presents a sample environment designed to apply an electric field to single-crystal samples in situ on the small-molecule single-crystal diffraction beamline I19, Diamond Light Source (UK). The configuration and operation of the cell is described as well as its application to studies of a proton-transfer colour-change material