3,285 research outputs found
Adhesive bonding and the use of corrosion resistant primers
The use of an anti-corrosive primer has been shown to be essential to assure survival of a bonded structure in a hostile environment, particularly if a stress is to be applied to the adhesively bonded joint during the environmental exposure. For example, the Lockheed L-1011 TriStar assembly, after exhaustive evaluation tests specifies use of chromate filled inhibitive polysulfide sealants, and use of corrosion inhibiting adhesive primers prior to structural bonding with film adhesive
Guide to the Identification of Poplar Cultivars on the Prairies
This paper provides those who work with poplars in the prairies region of Canada with an easy-to-use leaf and twig key and detailed morphological descriptions of the more commonly planted cultivars. Recommendations for their use, notes on growth, natural pruning, susceptibility to insects and diseases, and tolerance to climatic extremes are also provided
The Theoretical Astrophysical Observatory: Cloud-Based Mock Galaxy Catalogues
We introduce the Theoretical Astrophysical Observatory (TAO), an online
virtual laboratory that houses mock observations of galaxy survey data. Such
mocks have become an integral part of the modern analysis pipeline. However,
building them requires an expert knowledge of galaxy modelling and simulation
techniques, significant investment in software development, and access to high
performance computing. These requirements make it difficult for a small
research team or individual to quickly build a mock catalogue suited to their
needs. To address this TAO offers access to multiple cosmological simulations
and semi-analytic galaxy formation models from an intuitive and clean web
interface. Results can be funnelled through science modules and sent to a
dedicated supercomputer for further processing and manipulation. These modules
include the ability to (1) construct custom observer light-cones from the
simulation data cubes; (2) generate the stellar emission from star formation
histories, apply dust extinction, and compute absolute and/or apparent
magnitudes; and (3) produce mock images of the sky. All of TAO's features can
be accessed without any programming requirements. The modular nature of TAO
opens it up for further expansion in the future.Comment: 17 pages, 11 figures, 2 tables; accepted for publication in ApJS. The
Theoretical Astrophysical Observatory (TAO) is now open to the public at
https://tao.asvo.org.au/. New simulations, models and tools will be added as
they become available. Contact [email protected] if you have data you
would like to make public through TAO. Feedback and suggestions are very
welcom
A comparative study of the efficacy of a canarypox based recombinant leukaemia vaccine against a natural contact FeLV challenge in cats
Semi-Analytic Galaxy Evolution (SAGE): Model Calibration and Basic Results
This paper describes a new publicly available codebase for modelling galaxy
formation in a cosmological context, the "Semi-Analytic Galaxy Evolution"
model, or SAGE for short. SAGE is a significant update to that used in Croton
et al. (2006) and has been rebuilt to be modular and customisable. The model
will run on any N-body simulation whose trees are organised in a supported
format and contain a minimum set of basic halo properties. In this work we
present the baryonic prescriptions implemented in SAGE to describe the
formation and evolution of galaxies, and their calibration for three N-body
simulations: Millennium, Bolshoi, and GiggleZ. Updated physics include: gas
accretion, ejection due to feedback, and reincorporation via the galactic
fountain; a new gas cooling--radio mode active galactic nucleus (AGN) heating
cycle; AGN feedback in the quasar mode; a new treatment of gas in satellite
galaxies; and galaxy mergers, disruption, and the build-up of intra-cluster
stars. Throughout, we show the results of a common default parameterization on
each simulation, with a focus on the local galaxy population.Comment: 15 pages, 9 figures, accepted for publication in ApJS. SAGE is a
publicly available codebase for modelling galaxy formation in a cosmological
context, available at https://github.com/darrencroton/sage Questions and
comments can be sent to Darren Croton: [email protected]
Possible surface plasmon polariton excitation under femtosecond laser irradiation of silicon
The mechanisms of ripple formation on silicon surface by femtosecond laser
pulses are investigated. We demonstrate the transient evolution of the density
of the excited free-carriers. As a result, the experimental conditions required
for the excitation of surface plasmon polaritons are revealed. The periods of
the resulting structures are then investigated as a function of laser
parameters, such as the angle of incidence, laser fluence, and polarization.
The obtained dependencies provide a way of better control over the properties
of the periodic structures induced by femtosecond laser on the surface of a
semiconductor material.Comment: 11 pages, 8 figures, accepted for publication in Journal of Applied
Physic
Late Cretaceous (late Campanian-Maastrichtian) sea-surface temperature record of the Boreal Chalk Sea
The last 8 Myr of the Cretaceous greenhouse interval were characterized by a
progressive global cooling with superimposed cool/warm fluctuations. The
mechanisms responsible for these climatic fluctuations remain a source of
debate that can only be resolved through multi-disciplinary studies and
better time constraints. For the first time, we present a record of very
high-resolution (ca. 4.5 kyr) sea-surface temperature (SST) changes from the
Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark), tied to an
astronomical timescale of the late Campanian–Maastrichtian (74 to
66 Ma). Well-preserved bulk stable isotope trends and calcareous nannofossil
palaeoecological patterns from the fully cored Stevns-1 borehole show marked
changes in SSTs. These variations correlate with deep-water records of
climate change from the tropical South Atlantic and Pacific oceans but differ
greatly from the climate variations of the North Atlantic. We demonstrate
that the onset and end of the early Maastrichtian cooling and of the large
negative Campanian–Maastrichtian boundary carbon isotope excursion are
coincident in the Chalk Sea. The direct link between SSTs and δ13C
variations in the Chalk Sea reassesses long-term glacio-eustasy as the
potential driver of carbon isotope and climatic variations in the
Maastrichtian
X-Device Query Processing by Bitwise Distribution
The diversity of hardware components within a single system calls for strategies for efficient cross-device data processing. For exam- ple, existing approaches to CPU/GPU co-processing distribute individual relational operators to the “most appropriate” device. While pleasantly simple, this strategy has a number of problems: it may leave the “inappropriate” devices idle while overloading the “appropriate” device and putting a high pressure on the PCI bus. To address these issues we distribute data among the devices by par- tially decomposing relations at the granularity of individual bits. Each of the resulting bit-partitions is stored and processed on one of the available devices. Using this strategy, we implemented a processor for spatial range queries that makes efficient use of all available devices. The performance gains achieved indicate that bitwise distribution makes a good cross-device processing strategy
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