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Further Developments in Process Mapping and Modelling in Direct Metal Selective Laser Melting
This paper advances previous reported work on the mapping and modelling of single
tracks and layers produced in powder beds of tool steel and stainless steel powders by a CO2
laser. For single tracks it reports on predicted and simulated track masses. It validates the
simulations, including the use of absorption close to 1.0 when cylindrical tracks are formed. It
also reports on melt pool temperature calculations and estimated melt pool dimensions which are
used, in conjunction with bed physical properties, to explain why the single tracks form as either
continuous with a crescent shape cross-section, continuous with an elliptical section,
discontinuously irregularly broken, discontinuously balled or only partially melted as scan
speeds and laser powers change. It then extends its scope, experimentally, to consider effects of
scan spacing on single layer formation.Mechanical Engineerin
Maximal multihomogeneity of algebraic hypersurface singularities
From the degree zero part of logarithmic vector fields along an algebraic
hypersurface singularity we indentify the maximal multihomogeneity of a
defining equation in form of a maximal algebraic torus in the embedded
automorphism group. We show that all such maximal tori are conjugate and in
one-to-one correspondence to maxmimal tori in the degree zero jet of the
embedded automorphism group.
The result is motivated by Kyoji Saito's characterization of quasihomogeneity
for isolated hypersurface singularities and extends its formal version and a
result of Hauser and Mueller.Comment: 5 page
Infrared study of spin crossover Fe-picolylamine complex
Infrared (IR) absorption spectroscopy has been used to probe the evolution of
microscopic vibrational states upon the temperature- and photo-induced spin
crossovers in [Fe(2-picolylamine)3]Cl2EtOH (Fe-pic). To overcome the small
sizes and the strong IR absorption of the crystal samples used, an IR
synchrotron radiation source and an IR microscope have been used. The obtained
IR spectra of Fe-pic show large changes between high-spin and low-spin states
for both the temperature- and the photo- induced spin crossovers. Although the
spectra in the temperature- and photo-induced high-spin states are relatively
similar to each other, they show distinct differences below 750 cm-1. This
demonstrates that the photo-induced high-spin state involves microscopically
different characters from those of the temperature-induced high-spin state. The
results are discussed in terms of local pressure and structural deformations
within the picolylamine ligands, and in terms of their possible relevance to
the development of macroscopic photo-induced phase in Fe-pic.Comment: 6 pages (text) and 6 figures,submitted to J. Phys. Soc. Jp
Modelling Social Structures and Hierarchies in Language Evolution
Language evolution might have preferred certain prior social configurations
over others. Experiments conducted with models of different social structures
(varying subgroup interactions and the role of a dominant interlocutor) suggest
that having isolated agent groups rather than an interconnected agent is more
advantageous for the emergence of a social communication system. Distinctive
groups that are closely connected by communication yield systems less like
natural language than fully isolated groups inhabiting the same world.
Furthermore, the addition of a dominant male who is asymmetrically favoured as
a hearer, and equally likely to be a speaker has no positive influence on the
disjoint groups.Comment: 14 pages, 3 figures, 1 table. In proceedings of AI-2010, The
Thirtieth SGAI International Conference on Innovative Techniques and
Applications of Artificial Intelligence, Cambridge, England, UK, 14-16
December 201
Anomalous magnetotransport in (YGd)Co alloys: interplay of disorder and itinerant metamagnetism
New mechanism of magnetoresistivity in itinerant metamagnets with a
structural disorder is introduced basing on analysis of experimental results on
magnetoresistivity, susceptibility, and magnetization of structurally
disordered alloys (YGd)Co. In this series, YCo is an
enhanced Pauli paramagnet, whereas GdCo is a ferrimagnet (T=400
K) with Gd sublattice coupled antiferromagnetically to the itinerant Co-3d
electrons. The alloys are paramagnetic for . Large positive
magnetoresistivity has been observed in the alloys with magnetic ground state
at temperatures TT. We show that this unusual feature is linked to
a combination of structural disorder and metamagnetic instability of itinerant
Co-3d electrons. This new mechanism of the magnetoresistivity is common for a
broad class of materials featuring a static magnetic disorder and itinerant
metamagnetism.Comment: 7 pages 7 figure
Does information science need history and foundations?
Author(s) retain copyright, but ASIS & T receives an exclusive publication license As ASIS&T looks to the future, all community members are invited to contribute to a shared vision for information science. As a program of the SIG for History and Foundations (SIG-HFIS), this alternative event focuses on developing a vision for conceptual, philosophical, theoretical and historical work in information science. This event will provide a participatory platform to investigate questions such as: What is the domain of history and foundations? How does it relate to other research areas in the information field? The event will involve panelist interviews with diverse scholars, small-group discussions of big questions for history and foundations, and the presentation of a new idea-sharing platform, the HFIS Wishlist. This event will be a locus for participation and inspiration regarding historical and foundations work in information science as part of formulating a future vision for SIG-HFIS, ASIS&T, and the information field more broadly
A New Galactic Extinction Map of the Cygnus Region
We have made a Galactic extinction map of the Cygnus region with 5' spatial
resolution. The selected area is 80^\circ to 90^\circ in the Galactic longitude
and -4^\circ to 8^\circ in the Galactic latitude. The intensity at 140 \mum is
derived from the intensities at 60 and 100 \mum of the IRAS data using the
tight correlation between 60, 100, and 140 \mum found in the Galactic plane.
The dust temperature and optical depth are calculated with 5' resolution from
the 140 and 100 \mum intensity, and Av is calculated from the optical depth. In
the selected area, the mean dust temperature is 17 K, the minimum is 16 K, and
the maximum is 30 K. The mean Av is 6.5 mag, the minimum is 0.5 mag, and the
maximum is 11 mag. The dust temperature distribution shows significant spatial
variation on smaller scales down to 5'. Because the present study can trace the
5'-scale spatial variation of the extinction, it has an advantage over the
previous studies, such as the one by Schlegel, Finkbeiner, & Davis, who used
the COBE/DIRBE data to derive the dust temperature distribution with a spatial
resolution of 1^\circ. The difference of Av between our map and Schlegel et
al.'s is \pm 3 mag. A new extinction map of the entire sky can be produced by
applying the present method.Comment: 27 pages, 14 figures, accepted for publication in Ap
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