4,143 research outputs found
Surviving gas expulsion with substructure
We investigate the reaction of clumpy stellar distributions to gas expulsion. We show
that regions containing highly unbound substructures/subclusters after gas expulsion
can produce a significant final bound cluster. The key quantity in determining if a
region is able to form a bound cluster is the global virial ratio, and so regions must
be looked at as a whole rather than by individual substructure/subclusters when
determining if they might survive as a bound cluster
Macrostructural analysis : unravelling polyphase glacitectonic histories
Many Pleistocene glacial profiles look extremely simple, comprising till, or glacitectonite, overlying
older sediments or bedrock (Figure 4.1). In more complex sequences the till may itself be overlain by
younger sediments laid down as the ice retreated or during a completely separate, later phase of
advance. Macroscopically, subglacial traction tills (Evans et al., 2007) are typically massive,
unstructured deposits suggesting that it should be relatively straightforward to unravel the
glacitectonic deformation history recorded by the sequence. Many reconstructions do indeed look
very simple, slabs of sediment have been tilted and stacked and then overridden by the glacier to
cap the structure with till. Added to this is the use of vertical exaggeration which makes the whole
structure look like alpine tectonics (for an example see fig. 5 in van Gijssel, 1987). Dropping the
exaggeration led to the recognition that actually we were looking at much more horizontal
structures, i.e. overriding nappes and not imbricated slabs (van der Wateren, 1987).
Traditionally (van der Meer, 1987) glaciotectonics was thought to relate to large structures
like big push moraines and not to smaller structures like drag structures underneath tills (Figure 4.2),
let alone to the tills themselves. With the notion that deforming bed tills are tectonically and not
sedimentologically structured and could be regarded as tectomicts (Menzies et al., 2006), comes the
realisation that glacitectonics happens across a wide range of scales, from the microscopic to tens of
kilometres. Only by realising the full range of glaciotectonic scales can we hope to understand the
processes
Review Of Carbon Nanotubes Growth And Synthesis.
Carbon nanotubes are tubular nanostructures derived from rolled graphene planes. Carbon nanotubes are fullerenes related structures but a fullerenes's carbon form a sphere;
while a nanotubes are cylindrical. The growth mechanism of carbon nanotubes depend on
the synthesis method
Cystic fibrosis co-existing with trisomy 21
AbstractPrevious reports of children with co-existence of cystic fibrosis and full trisomy 21 suggest a very poor prognosis, with the majority of cases dying in infancy and the oldest reported survivor being 6years of age. We report the case of a young man with genetically confirmed trisomy 21 and homozygous for the F508del cystic fibrosis mutation. Despite the diagnosis of cystic fibrosis being delayed until the age of 2years he has transitioned to adult services and is now 25years of age. Currently he has poor lung function and a continuous ambulatory oxygen requirement
Chaotic inflation in Jordan frame supergravity
We consider the inflationary scenario with non-minimal coupling in 4D Jordan
frame supergravity. We find that there occurs a tachyonic instability along the
direction of the accompanying non-inflaton field in generic Jordan frame
supergravity models. We propose a higher order correction to the Jordan frame
function for solving the tachyonic mass problem and show that the necessary
correction can be naturally generated by the heavy thresholds without spoiling
the slow-roll conditions. We discuss the implication of the result on the Higgs
inflation in NMSSM.Comment: 16 pages, no figures, version to be published in JCA
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