Aerodynamic Sensing for a Fixed Wing UAS Operating at High Angles of Attack

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97104/1/AIAA2012-4416.pd

A self-consistent phase-space distribution function for the anisotropic dark matter halo of the Milky Way

Dark Matter (DM) direct detection experiments usually assume the simplest possible ‘Standard Halo Model’ for the Milky Way (MW) halo in which the velocity distribution is Maxwellian. This model assumes that the MW halo is an isotropic, isothermal sphere, hypotheses that are unlikely to be valid in reality. An alternative approach is to derive a self-consistent solution for a particular mass model of the MW (i.e. obtained from its gravitational potential) using the Eddington formalism, which assumes isotropy. In this paper we extend this approach to incorporate an anisotropic phase-space distribution function. We perform Bayesian scans over the parameters defining the mass model of the MW and parameterising the phase-space density, implementing constraints from a wide range of astronomical observations. The scans allow us to estimate the precision reached in the reconstruction of the velocity distribution (for different DM halo profiles). As expected, allowing for an anisotropic velocity tensor increases the uncertainty in the reconstruction of f (v), but the distribution can still be determined with a precision of a factor of 4-5. The mean velocity distribution resembles the isotropic case, however the amplitude of the high-velocity tail is up to a factor of 2 larger. Our results agree with the phenomenological parametrization proposed in Mao et al. (2013) as a good fit to N-body simulations (with or without baryons), since their velocity distribution is contained in our 68% credible interval

Event Texture Search for Phase Transitions in Pb+Pb Collisions

NA44 uses a 512 channel Si pad array covering $1.5 <\eta < 3.3$ to study charged hadron production in 158 A GeV Pb+Pb collisions at the CERN SPS. We apply a multiresolution analysis, based on a Discrete Wavelet Transformation, to probe the texture of particle distributions event-by-event, allowing simultaneous localization of features in space and scale. Scanning a broad range of multiplicities, we search for signals of clustering and of critical behavior in the power spectra of local density fluctuations. The data are compared with detailed simulations of detector response, using heavy ion event generators, and with a reference sample created via event mixing. An upper limit is set on the probability and magnitude of dynamical fluctuations

Mechanical and Physical Properties - A Way to Assess Quality of Laser Sintered Parts

The aim of this paper is the description and evaluation of physical properties like porosity and density and their influence on mechanical properties of laser sintered polyamide parts. For example, by reducing the porosity an increase of mechanical properties is possible. The correlation of laser parameters to these properties is investigated in detail. The energy density is an important parameter for the laser sintering process. By changing laser power, scan velocity and hatch distance an influence on manufactured components is given. A systematic variation of all three laser parameters is performed. A comparison of results obtained at constant energy densities obtained by varying these relevant parameters accordingly is shown as well.Mechanical Engineerin

Thermal, spectral and AFM studies of calcium silicate hydrate-polymer nanocomposite material

A non-ionic polymer (poly(vinyl alcohol) (PVA)) has been incorporated into the inorganic layers of calcium silicate hydrate (C?S?H) during precipitation of quasicrystalline C?S?H from aqueous solution. C?S?H and a C?S?H-polymer nanocomposite (C?S?HPN) material were synthesized and characterized by X-ray fluorescence (XRF), energy dispersive spectroscopy (EDS), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR) and 13C cross-polarization nuclear magnetic resonance (13C CP NMR) spectroscopy, atomic force microscopy (AFM), thermal conductivity, thermogravimetric analysis (TG) and differential thermal analysis (DTA). Thermal conductivity of PVA, C?S?H and C?S?HPN material was studied in the temperature range 25?50\ub0C. C?S?HPN materials exhibited the highest thermal conductivity at 25 and 50\ub0C. The thermal conductivity increases from 25 to 50\ub0C are 7.03, 17.46 and 14.85% for PVA, C?S?H and C?S?HPN material, respectively. Three significant decomposition temperature ranges were observed on the TG curve of C?S?HPN material.Un polym\ue8re non ionique (poly(alcool de vinyle) (PVA)) a \ue9t\ue9 incorpor\ue9 dans les couches inorganiques d'hydrate de silicate de calcium (C-S-H) durant la pr\ue9cipitation de C-S-H quasicristallin \ue0 partir d'une solution aqueuse. On a synth\ue9tis\ue9 et caract\ue9ris\ue9 le C-S-H ainsi qu'un mat\ue9riau nanocomposite de C-S-H/polym\ue8re (C-S-HPN), par fluorescence X (XRF), par spectroscopie de rayons X \ue0 dispersion d'\ue9nergie (EDS), par spectroscopie \ue0 l'angle magique en r\ue9sonance magn\ue9tique nucl\ue9aire 29Si (MAS NMR 29Si) et par spectroscopie \ue0 r\ue9sonance magn\ue9tique nucl\ue9aire \ue0 polarisation crois\ue9e 13C (CP NMR 13C), par microscopie \ue0 forces atomiques (AFM), par conductibilit\ue9 thermique, par analyse thermo-gravim\ue9trique (TGA) et par analyse thermique diff\ue9rentielle (DTA). On a \ue9tudi\ue9 la conductibilit\ue9 thermique des mat\ue9riaux PVA, C-S-H et C-S-HPN dans la gamme de temp\ue9ratures de 25 \ue0 50 \ub0C. Les mat\ue9riaux C-S-HPN ont affich\ue9 la conductibilit\ue9 thermique la plus \ue9lev\ue9e \ue0 25 \ub0C et \ue0 50 \ub0C. Les valeurs d'augmentation de la conductibilit\ue9 thermique pour les mat\ue9riaux PVA, C-S-H et C-S-HPN dans cette gamme de temp\ue9ratures sont respectivement de 7,03, de 17,46 et de 14,85 %. Trois (3) plages de temp\ue9rature de d\ue9composition appr\ue9ciables ont \ue9t\ue9 observ\ue9es sur la courbe de TGA du mat\ue9riau C-S-HPN.Peer reviewed: YesNRC publication: Ye

Effect of temperature on dynamic and steady-state shear rheological properties of Jambolan (Syzygium cumini) pulp

Jambolan is an exotic fruit rich in phenolic compounds with many health benefits. The study of fruit's rheological properties plays key roles in its industrial processing and obtainment of products. The present work evaluated the time-dependent and steady-state shear rheological properties of Jambolan pulp at several temperatures. The Jambolan pulp presented thixotropy as a time-dependent property and also showed shear thinning behaviour with yield stress in the steady shear measurements. The Figoni-Shoemaker and Hershel-Buckley models adequately described both the product rheological phenomena. During the oscillatory analysis, the pulp showed some viscoelastic properties, increasing when the oscillatory frequency (ω) increased. All previous parameters also verified the impact of the temperature. The increment in temperature resulted in a reduction in consistency levels. In the temperature range studied, the viscoelastic solid component presented higher values than the viscous component. The thixotropic phenomenon and the presence of the yield stress can be related to this. Viscoelastic moduli decreased with the increase in temperature. When relevant, the Arrhenius’ Activation Energy of some model parameters were calculated. The data obtained are applicable for future studies, to improve industrial process design, and to evaluate food properties.The authors are grateful to CAPES and CNPq (n◦ 140564/2014–4) for their financial support.Peer reviewe

Space charge behavior on epoxy based nanocomposite materials with a high nanoparticule content

International audienc

Space charge behavior on epoxy based nanocomposite materials with a high nanoparticule content

International audienc