24,939 research outputs found
Quantification of drag and lift imposed by pop-up satellite archival tags and estimation of the metabolic cost to cownose rays (Rhinoptera bonasus)
The recent development of the pop-up satellite archival tag
(PSAT) has allowed the collection of information on a tagged animal, such as geolocation, pressure (depth), and
ambient water temperature. The success of early studies, where PSATs were used on pelagic fishes, has spurred increasing interest in the use of these tags on a large variety of species and age groups. However, some species and age groups may not be suitable candidates for carrying a
PSAT because of the relatively large size of the tag and the consequent energy cost to the study animal. We examined potential energetic costs to carrying a tag for the cownose ray (Rhinoptera bonasus). Two forces act on an animal tagged with a PSAT: lift from the PSATs buoyancy and drag as
the tag is moved through the water column. In a freshwater flume, a spring scale measured the total force exerted by a PSAT at flume velocities from 0.00 to 0.60 m/s. By measuring
the angle of deflection of the PSAT at each velocity, we separated total force into its constituent forces — lift and
drag. The power required to carry a PSAT horizontally through the water was then calculated from the drag force and velocity. Using published metabolic rates, we calculated the power for a ray of a given size to swim at a specified velocity (i.e., its swimming power). For each velocity, the power required to carry a PSAT was compared to the swimming power expressed as a percentage, %TAX (Tag
Altered eXertion). A %TAX greater than 5% was felt to be energetically significant. Our analysis indicated that a ray larger than 14.8 kg can carry a PSAT without exceeding this criterion. This method of estimating swimming power can be applied to other species and would allow a researcher to decide the suitability of a given study animal for tagging with a PSAT
Battery storage optimization and design studies
Storage effects on performance of silver zinc and silver cadmium batterie
3D performance capture for facial animation
This work describes how a photogrammetry based 3D capture system can be used as an input device for animation. The 3D Dynamic Capture System is used to capture the motion of a human face, which is extracted from a sequence of 3D models captured at TV frame rate. Initially the positions of a set of landmarks on the face are extracted. These landmarks are then used to provide motion data in two different ways. First, a high level description of the movements is extracted, and these can be used as input to a procedural animation package (i.e. CreaToon). Second the landmarks can be used as registration points for a conformation process where the model to be animated is modified to match the captured model. This approach gives a new sequence of models, which have the structure of the drawn model but the movement of the captured sequence
Predicting outcome following colorectal cancer surgery using Colorectal Biochemical and Haematological Outcome Model (Colorectal BHOM)
A review of residual stress analysis using thermoelastic techniques
Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis
that is based on infra-red thermography. The technique has proved to be extremely effective for
studying elastic stress fields and is now well established. It is based on the measurement of the
temperature change that occurs as a result of a stress change. As residual stress is essentially a
mean stress it is accepted that the linear form of the TSA relationship cannot be used to
evaluate residual stresses. However, there are situations where this linear relationship is not
valid or departures in material properties due to manufacturing procedures have enabled
evaluations of residual stresses. The purpose of this paper is to review the current status of
using a TSA based approach for the evaluation of residual stresses and to provide some
examples of where promising results have been obtained
The Dog on the Ship: The "Canis Major Dwarf Galaxy" as an Outlying Part of the Argo Star System
Overdensities in the distribution of low latitude, 2MASS giant stars are
revealed by systematically peeling away from sky maps the bulk of the giant
stars conforming to ``isotropic'' density laws generally accounting for known
Milky Way components. This procedure, combined with a higher resolution
treatment of the sky density of both giants and dust allows us to probe to
lower Galactic latitudes than previous 2MASS giant star studies. While the
results show the swath of excess giants previously associated with the
Monoceros ring system in the second and third Galactic quadrants at distances
of 6-20 kpc, we also find a several times larger overdensity of giants in the
same distance range concentrated in the direction of the ancient constellation
Argo. Isodensity contours of the large structure suggest that it is highly
elongated and inclined by about 3 deg to the disk, although details of the
structure -- including the actual location of highest density, overall extent,
true shape -- and its origin, remain unknown because only a fraction of it lies
outside highly dust-obscured, low latitude regions. Nevertheless, our results
suggest that the 2MASS M giant overdensity previously claimed to represent the
core of a dwarf galaxy in Canis Major (l ~ 240 deg) is an artifact of a dust
extinction window opening to the overall density rise to the more significant
Argo structure centered at larger longitude (l ~ 290 +- 10 deg, b ~ -4 +- 2
deg).Comment: 4 pages, 4 figure
Band structures of rare gas solids within the GW approximation
Band structures for solid rare gases (Ne, Ar) have been calculated using the
GW approximation. All electron and pseudopotential ab initio calculations were
performed using Gaussian orbital basis sets and the dependence of particle-hole
gaps and electron affinities on basis set and treatment of core electrons is
investigated. All electron GW calculations have a smaller particle-hole gap
than pseudopotential GW calculations by up to 0.2 eV. Quasiparticle electron
and hole excitation energies, valence band widths and electron affinities are
generally in very good agreement with those derived from optical absorption and
photoemission measurements.Comment: 7 pages 1 figur
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