8,924 research outputs found
Evaluating Teaching Methods: Is It Worth Doing Right?
Reviewers of manuscripts on classroom experiments often ask the authors to provide evidence of the effectiveness of the method, presumably to justify substituting experiments for lectures. After reviewing the current state of evaluation methodology, we argue that such evidence may be neither sufficient nor even necessary for the purpose.Teaching/Communication/Extension/Profession,
Anti-Unruh Phenomena
We find that a uniformly accelerated particle detector coupled to the vacuum
can cool down as its acceleration increases, due to relativistic effects. We
show that in (1+1)-dimensions, a detector coupled to the scalar field vacuum
for finite timescales (but long enough to satisfy the KMS condition) has a KMS
temperature that decreases with acceleration, in certain regimes. This
contrasts with the heating that one would expect from the Unruh effect.Comment: 6 pages, 5 figures. RevTex 4.1. V2. Typos in the plots labeling
corrected and plot rescaled. New discussion section added. Title change
P-V Criticality in Quasitopological Gravity
We investigate the thermodynamic behaviour of AdS quasitopological black hole
solutions in the context of extended thermodynamic phase space, in which the
cosmological constant induces a pressure with a conjugate volume. We find that
the third order exact quasitopological solution exhibits features consistent
with the third order Lovelock solutions for positive quasitopological coupling,
including multiple reentrant phase transitions and isolated critical points.
For negative coupling we find the first instances of both reentrant phase
transitions and thermodynamic singularities in five dimensions, along with
other modified thermodynamic behaviour compared to Einstein-AdS-Gauss Bonnet
gravity.Comment: 20 pages, 15 figures, REVTeX 4-1; updated to match published versio
EC02-171 Canada Thistle
Canada thistle [Cirsium arvense (L) Scop.] is one of the seven species defined by Nebraska law as a noxious weed. At least 35 other states also have determined by law that Canada thistle poses a threat to the economic, social, and aesthetic well-being of the residents of their state. Canada thistle is probably the most widespread of all the thistle species and many land managers consider it the most difficult thistle to control. In Nebraska, Canada thistle is estimated to infest 460,000 acres
Changing habitat associations of a thermally constrained species, the silver-spotted skipper butterfly, in response to climate warming
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