31,104 research outputs found
Ectoparasitic Arthropods Collected From Some Northern Ohio Mammals
Ectoparasitic arthropods were collected from some fur-bearing mammals in northern Ohio. Specimens representing seven mammalian species were examined and found to collectively harbor acarines, fleas, and biting lice. Species determinations were made and new host and state records noted
Modelling of the B-type binaries CW Cep and U Oph: A critical view on dynamical masses, core boundary mixing, and core mass
Context: Intermediate-Mass stars are often overlooked as they are not
supernova progenitors but still host convective cores and complex atmospheres
which require computationally expensive treatment. Due to this, there is a
general lack of such stars modelled by state of the art stellar structure and
evolution codes. Aims: This paper aims to use high-quality spectroscopy to
update the dynamically obtained stellar parameters and produce a new
evolutionary assessment of the bright B0.5+B0.5 and B5V+B5V binary systems CW
Cep and U Oph. Methods: We use new spectroscopy obtained with the Hermes
spectrograph to revisit the photometric binary solution of the two systems. The
updated mass ratio and effective temperatures are incorporated to obtain new
dynamical masses for the primary and secondary. With these, we perform
isochrone-cloud based evolutionary modelling to investigate the core properties
of these stars. Results: We report the first abundances for CW Cep and U Oph as
well as report an updated dynamical solution for both systems. We find that we
cannot uniquely constrain the amount of core boundary mixing in any of the
stars we consider. Instead, we report their core masses and compare our results
to previous studies. Conclusions: We find that the per-cent level precision on
fundamental stellar quantities are accompanied with core mass estimates to
between ~ 5-15%. We find that differences in analysis techniques can lead to
substantially different evolutionary modeComment: 15 pages, 7 figures, two appendices with 4 figures each. Accepted for
publication in Astronomy & Astrophysic
Crossover Between Weakly and Strongly Self-avoiding Random Surfaces
We investigate the crossover between weak and strong self-avoidance in a
simulation of random surfaces with extrinsic curvature. We consider both
dynamically triangulated and rigid surfaces with the two possible
discretizations of the extrinsic curvature term.Comment: 5 page
Decorating Random Quadrangulations
On various regular lattices (simple cubic, body centred cubic..) decorating
an edge with an Ising spin coupled by bonds of strength L to the original
vertex spins and competing with a direct anti-ferromagnetic bond of strength
alpha L can give rise to three transition temperatures for suitable alpha. The
system passes through ferromagnetic, paramagnetic, anti-ferromagnetic and
paramagnetic phases respectively as the temperature is increased.
For the square lattice on the other hand multiple decoration is required to
see this effect. We note here that a single decoration suffices for the Ising
model on planar random quadrangulations (coupled to 2D quantum gravity). Other
random bipartite lattices such as the Penrose tiling are more akin to the
regular square lattice and require multiple decoration to have any affect.Comment: 6 pages + 5 figure
The effect of very low-calorie diets on renal and hepatic outcomes : a systematic review
Peer reviewedPublisher PD
The Gonihedric Ising Model and Glassiness
The Gonihedric 3D Ising model is a lattice spin model in which planar Peierls
boundaries between + and - spins can be created at zero energy cost. Instead of
weighting the area of Peierls boundaries as the case for the usual 3D Ising
model with nearest neighbour interactions, the edges, or "bends" in an
interface are weighted, a concept which is related to the intrinsic curvature
of the boundaries in the continuum.
In these notes we follow a roughly chronological order by first reviewing the
background to the formulation of the model, before moving on to the elucidation
of the equilibrium phase diagram by various means and then to investigation of
the non-equilibrium, glassy behaviour of the model.Comment: To appear as Chapter 7 in Rugged Free-Energy Landscapes - An
Introduction, Springer Lecture Notes in Physics, 736, ed. W. Janke, (2008
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