2,159 research outputs found

    When should we put a name to a picture?

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    Este artigo aborda as implicações de dar nomes ou títulos a obras de arte e imagens e como isso interfere na interpretação. Argumenta que nomear uma obra é uma ferramenta para a leitura, especialmente durante o desenvolvimento de teorias intuitivas sobre arte por crianças, tornando-se uma parte positiva no processo de interpretação estética. Apresenta um modo de categorizar a função de nomear a obra. Comenta os resultados iniciais de um estudo empírico, indicando que, para a criança, atribuir um nome para a imagem é tão importante quanto identificar a intenção do artista.It is only relatively recently that the Anglophone art-education community started publically to collate its communal body of research. There are at least three ways of getting art students interested in research. I focus on just one of the ways, and note that sometimes it may be most important to name to a picture, as an occasional tool to help visual interpretation. Especially during the development of someone’s intuitive theory of art. There is a question about what very young viewers intuitively try to interpret: (a) the meaning of the picture that they see, or (b) the artist’s idea of what the picture means. I put forward a way of sorting out a role for naming here: initial results seem to indicate that for young children settling on a name for a picture is as important as identifying an artist’s intent. Of course, criteria might change with development, but it is always interesting to look at research into the origins of an intuitive theory of picture

    Cost-efficient manufacturing of composite structures

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    The Advanced Composites Technology (ACT) program is seeking research breakthroughs that will allow structures made of graphite epoxy materials to replace metals in the wings and fuselages of future aircrafts. NASA's goals are to reduce acquisition cost by 20 to 25 percent, structural weight for a resized aircraft by 40 to 50 percent, and the number of parts by half compared to current production aluminum aircraft. The innovative structural concepts, materials, and fabrication techniques emerging from the ACT program are described, and the relationship between aerospace developments and industrial, commercial, and sporting goods applications are discussed

    Orbital mixing and nesting in the bilayer manganites La22x_{2-2x}Sr1+2x_{1+2x}Mn2_2O7_7

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    A first principles study of La22x_{2-2x}Sr1+2x_{1+2x}Mn2_2O7_7 compounds for doping levels 0.3x0.50.3\leq x\leq 0.5 shows that the low energy electronic structure of the majority spin carriers is determined by strong momentum dependent interactions between the Mn ege_g dx2y2d_{x^2-y^2} and d3z2r2d_{3z^2-r^2} orbitals, which in addition to an xx dependent Jahn-Teller distortion, differ in the ferromagnetic and antiferromagnetic phases. The Fermi surface exhibits nesting behavior that is reflected by peaks in the static susceptibility, whose positions as a function of momentum have a non-trivial dependence on xx.Comment: 4 pages, 5 figures, publishe

    Anisotropic Neutron Spin Resonance in Superconducting BaFe1.9_{1.9}Ni0.1_{0.1}As2_2

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    We use polarized inelastic neutron scattering to show that the neutron spin resonance below TcT_c in superconducting BaFe1.9_{1.9}Ni0.1_{0.1}As2_2 (Tc=20T_c=20 K) is purely magnetic in origin. Our analysis further reveals that the resonance peak near 7~meV only occurs for the planar response. This challenges the common perception that the spin resonance in the pnictides is an isotropic triplet excited state of the singlet Cooper pairs, as our results imply that only the S001=±1S_{001}=\pm1 components of the triplet are involved

    The Recent Star Formation History of NGC 5102

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    We present Hubble Space Telescope photometry of young stars in NGC 5102, a nearby gas-rich post-starburst S0 galaxy with a bright young stellar nucleus. We use the IAC-pop/MinnIAC algorithm to derive the recent star formation history in three fields in the bulge and disk of NGC 5102. In the disk fields, the recent star formation rate has declined monotonically and is now barely detectable, but a starburst is still in progress in the bulge and has added about 2 percent to the mass of the bulge over the last 200 Myr. Other studies of star formation in NGC 5102 indicate that about 20 percent of its stellar mass was added over the past Gyr. If this is correct, then much of the stellar mass of the bulge may have formed over this period. It seems likely that this star formation was fueled by the accretion of a gas-rich system with HI mass of about 2 x 10^9 Msol which has now been almost completely converted into stars. The large mass of recently formed stars and the blue colours of the bulge suggest that the current starburst, which is now fading, may have made a significant contribution to build the bulge of NGC 5102.Comment: 36 pages, 16 figures, accepted in A

    Bostonia: The Boston University Alumni Magazine. Volume 20

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    Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

    Evidence of nuclear disks in starburst galaxies from their radial distribution of supernovae

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    Galaxy-galaxy interactions are expected to be responsible for triggering massive star formation and possibly accretion onto a supermassive black hole, by providing large amounts of dense molecular gas down to the central kiloparsec region. Several scenarios to drive the gas further down to the central ~100 pc, have been proposed, including the formation of a nuclear disk around the black hole, where massive stars would produce supernovae. Here, we probe the radial distribution of supernovae and supernova remnants in the nuclear regions of the starburst galaxies M82, Arp 299-A, and Arp 220, by using high-angular resolution (< 0."1) radio observations published in the literature (for M82 and Arp 220), or obtained by ourselves from the European VLBI Network (Arp 299-A). Our main goal was to characterize the nuclear starbursts in those galaxies and thus test scenarios that propose that nuclear disks of sizes ~100 pc form in the central regions of starburst galaxies. We obtained the radial distribution of supernovae (SNe) in the nuclear starbursts of M82, Arp 299-A, and Arp 220, and derived scale-length values for the putative nuclear disks powering the bursts in those central regions. The scale lengths for the (exponential) disks range from ~20-30 pc for Arp 299-A and Arp 220, up to ~140 pc for M82. The radial distribution of SNe for the nuclear disks in Arp 299-A and Arp 220 is also consistent with a power-law surface density profile of exponent gamma=1, as expected from detailed hydrodynamical simulations of nuclear disks. Our results support scenarios where a nuclear disk of size ~100 pc is formed in (U)LIRGs, and sustained by gas pressure, in which case the accretion onto the black hole could be lowered by supernova feedback.Comment: Accepted for publication in Astronomy and Astrophysic
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