9,084 research outputs found
The Insects of Treeholes of Northern Indiana With Special Reference to \u3ci\u3eMegaselia Scalaris\u3c/i\u3e (Diptera: Phoridae) and \u3ci\u3eSpilomyia Longicornis\u3c/i\u3e (Diptera: Syrphidae)
The aquatic insect community of treeholes in northern Indiana was surveyed from 1983-1986. Twenty-three species, representing three orders and nine families, were found. Megaselia scalaris (Diptera: Phoridae) was collected on several occasions from rotholes, the first member of this family from treeholes. Examination of puparia of Spilomyia longicornis (Diptera: Syrphidae) indicated that the larva of this species has been previously described, but incorrectly associated with the genus Xylata
Chuck for delicate drills
Development of oil film technique to couple power between drive spindle and drill chuck for delicate drilling operations is discussed. Oil film permits application of sufficient pressure, but stops rotating when drill jams. Illustration of equipment is provided
Constraining the quintessence equation of state with SnIa data and CMB peaks
Quintessence has been introduced as an alternative to the cosmological
constant scenario to account for the current acceleration of the universe. This
new dark energy component allows values of the equation of state parameter
, and in principle measurements of cosmological distances to
Type Ia supernovae can be used to distinguish between these two types of
models. Assuming a flat universe, we use the supernovae data and measurements
of the position of the acoustic peaks in the Cosmic Microwave Background (CMB)
spectra to constrain a rather general class of Quintessence potentials,
including inverse power law models and recently proposed Supergravity inspired
potentials. In particular we use a likelihood analysis, marginalizing over the
dark energy density , the physical baryon density
and the scalar spectral index , to constrain the slopes of our Quintessence
potential. Considering only the first Doppler peak the best fit in our range of
models gives . However, including the SnIa data and the three
peaks, we find an upper limit on the present value of the equation of state
parameter, at , a result that appears to
rule out a class of recently proposed potentials.Comment: Accepted for pubblication in PRD, 7 pages, 6 figures. New revised
analysi
Fanny Copeland and the geographical imagination
Raised in Scotland, married and divorced in the English south, an adopted Slovene, Fanny Copeland (1872 – 1970) occupied the intersection of a number of complex spatial and temporal conjunctures. A Slavophile, she played a part in the formation of what subsequently became the Kingdom of Yugoslavia that emerged from the First World War. Living in Ljubljana, she facilitated the first ‘foreign visit’ (in 1932) of the newly formed Le Play Society (a precursor of the Institute of British Geographers) and guided its studies of Solčava (a then ‘remote’ Alpine valley system) which, led by Dudley Stamp and commended by Halford Mackinder, were subsequently hailed as a model for regional studies elsewhere. Arrested by the Gestapo and interned in Italy during the Second World War, she eventually returned to a socialist Yugoslavia, a celebrated figure. An accomplished musician, linguist, and mountaineer, she became an authority on (and populist for) the Julian Alps and was instrumental in the establishment of the Triglav National Park. Copeland’s role as participant observer (and protagonist) enriches our understanding of the particularities of her time and place and illuminates some inter-war relationships within G/geography, inside and outside the academy, suggesting their relative autonomy in the production of geographical knowledge
Superhorizon curvaton amplitude in inflation and pre-big bang cosmology
We follow the evolution of the curvaton on superhorizon scales and check that
the spectral tilt of the curvaton perturbations is unchanged as the curvaton
becomes non-relativistic. Both inflation and pre-big bang cosmology can be
treated since the curvaton mechanism within the two scenarios works the same
way. We also discuss the amplitude of the density perturbations, which leads to
some interesting constrains on the pre-big bang scenario. It is shown that
within a SL(3,R) non-linear sigma model one of the three axions has the right
coupling to the dilaton and moduli to yield a flat spectrum with a high string
scale, if a quadratic non-perturbative potential is generated and an
intermediate string phase lasts long enough.Comment: 15 pages, LaTeX. Discussion and references adde
String mediated phase transitions
It is demonstrated from first principles how the existence of string-like structures can cause a system to undergo a phase transition. In particular, the role of topologically stable cosmic string in the restoration of spontaneously broken symmetries is emphasized. How the thermodynamic properties of strings alter when stiffness and nearest neighbor string-string interactions are included is discussed
The Critical Importance of Proving Market Impact in Sherman Act Antitrust Cases: A Review of the Second Circuit\u27s Recent Antitust Decisions
New type scalar fields for cosmic acceleration
We present a model where a non-conventional scalar field may act like dark
energy leading to cosmic acceleration. The latter is driven by an appropriate
field configuration, which result in an effective cosmological constant. The
potential role of such a scalar in the cosmological constant problem is also
discussed.Comment: 6 page
String Dilaton Fluid Cosmology
We investigate -dimensional string-dilaton cosmology with effective
dilaton potential in presence of perfect-fluid matter.We get exact solutions
parametrized by the constant \gam of the state equation p=(\gam-1)\rho, the
spatial dimension number , the bulk of matter, and the spatial curvature
constant . Several interesting cosmological behaviours are selected. Finally
we discuss the recovering of ordinary Einstein gravity starting from string
dominated regime and a sort of asymptotic freedom due to string effective
coupling.Comment: 16 pages, Latex, submitted to Int. Jou. Mod. Phys.
Governing in the Shadow of Intergovernmental Hierarchy: Delegation Failure and Executive Empowerment in the European Union
This is an Accepted Manuscript of an article published by Taylor & Francis in Perspectives on European Politics and Society on [date of publication], available online: http://wwww.tandfonline.com/[Article DOI]
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