1,191 research outputs found
The building stones and slates of Killin : an investigation of stone for the built heritage
The village of Killin lies in an area of dramatic landscape and mountain scenery. The use of local stone
in the buildings gives a direct connection to this landscape and reflects the local geology, comprising
mostly metamorphic rocks of Precambrian age –dominantly limestone, meta-sandstone, mica schist
and meta-igneous rocks. All of these (with the exception of the Loch Tay Limestone which was used for
soil improvement) were used in buildings and structures within the Killin Conservation Area.
The stone masonry in the village is classified into five categories; (1) cottages (mostly harled) built of
random rubble from field and river boulders and surface rock outcrops, (2) two storey buildings with
irregular coursed rubble walls of meta-sandstone and mica schist with large dressings of silver-grey
slabs of actinolite schist, (3) and (4) larger late 19th century buildings with dressings of Central Belt
sandstone used in combination with squared rubble walling of local actinolite schist and metasandstone.
The 5th masonry category represents relatively late buildings constructed using distinctive
imported stone types (e.g. whinstone, granite, red sandstone). These categories are broadly
chronological in order and reflect the development of architectural form along with improving
transportation of materials over time
Neutrino Interactions at Low and Medium Energies
We discuss the calculations for several neutrino induced reactions from low
energies to the GeV region. Special attention is paid to nuclear corrections
when the targets are medium or heavy nuclei. Finally, we present several ratios
of neutral to charged current reactions whose values on isoscalar targets can
be estimated accurately. The ratios are useful for investigating neutrino
oscillations in Long Baseline experiments.Comment: Contributed to 1st Workshop on Neutrino - Nucleus Interactions in the
Few GeV Region (NuInt01), Tsukuba, Japan, 13-16 Dec 2001. 9 pages, 15 figure
Preasymptotic nature of hadron scattering vs small-x HERA Data
We emphasize that recently observed regularities in hadron interactions and
deep-inelastic scattering are of preasymptotic nature and it is impossible to
make conclusions on the true asymptotic behavior of observables without
unitarization procedure. Unitarization is important and changes scattering
picture drastically.Comment: LaTeX file, 9 pages; 4 tarred, gzipped and uuencoded figures in a
separate fil
Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low Method
We investigate the "low-" method (developed by the CCFR/NUTEV
collaborations) to determine the neutrino flux in a wide band neutrino beam at
very low energies, a region of interest to neutrino oscillations experiments.
Events with low hadronic final state energy (of 1, 2 and 5 GeV)
were used by the MINOS collaboration to determine the neutrino flux in their
measurements of neutrino () and antineutrino (\nub_\mu) total cross
sections. The lowest energy for which the method was used in MINOS is
3.5 GeV, and the lowest \nub_\mu energy is 6 GeV. At these energies, the
cross sections are dominated by inelastic processes. We investigate the
application of the method to determine the neutrino flux for ,
\nub_\mu energies as low as 0.7 GeV where the cross sections are dominated by
quasielastic scattering and (1232) resonance production. We find that
the method can be extended to low energies by using values of 0.25
and 0.50 GeV, which is feasible in fully active neutrino detectors such as
MINERvA.Comment: 25 pages, 32 figures, to be published in European Physics Journal
Finite one dimensional impenetrable Bose systems: Occupation numbers
Bosons in the form of ultra cold alkali atoms can be confined to a one
dimensional (1d) domain by the use of harmonic traps. This motivates the study
of the ground state occupations of effective single particle states
, in the theoretical 1d impenetrable Bose gas. Both the system on a
circle and the harmonically trapped system are considered. The and
are the eigenvalues and eigenfunctions respectively of the one body
density matrix. We present a detailed numerical and analytic study of this
problem. Our main results are the explicit scaled forms of the density
matrices, from which it is deduced that for fixed the occupations
are asymptotically proportional to in both the circular
and harmonically trapped cases.Comment: 22 pages, 8 figures (.eps), uses REVTeX
Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector
We report results of a search for narrow resonances in e+ e- annihilation at
center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR
detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width
of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained
(at 90 % C.L.)
The influence of gene expression time delays on Gierer-Meinhardt pattern formation systems
There are numerous examples of morphogen gradients controlling long range signalling in developmental and cellular systems. The prospect of two such interacting morphogens instigating long range self-organisation in biological systems via a Turing bifurcation has been explored, postulated, or implicated in the context of numerous developmental processes. However, modelling investigations of cellular systems typically neglect the influence of gene expression on such dynamics, even though transcription and translation are observed to be important in morphogenetic systems. In particular, the influence of gene expression on a large class of Turing bifurcation models, namely those with pure kinetics such as the Gierer–Meinhardt system, is unexplored. Our investigations demonstrate that the behaviour of the Gierer–Meinhardt model profoundly changes on the inclusion of gene expression dynamics and is sensitive to the sub-cellular details of gene expression. Features such as concentration blow up, morphogen oscillations and radical sensitivities to the duration of gene expression are observed and, at best, severely restrict the possible parameter spaces for feasible biological behaviour. These results also indicate that the behaviour of Turing pattern formation systems on the inclusion of gene expression time delays may provide a means of distinguishing between possible forms of interaction kinetics. Finally, this study also emphasises that sub-cellular and gene expression dynamics should not be simply neglected in models of long range biological pattern formation via morphogens
Dynamical Systems approach to Saffman-Taylor fingering. A Dynamical Solvability Scenario
A dynamical systems approach to competition of Saffman-Taylor fingers in a
channel is developed. This is based on the global study of the phase space
structure of the low-dimensional ODE's defined by the classes of exact
solutions of the problem without surface tension. Some simple examples are
studied in detail, and general proofs concerning properties of fixed points and
existence of finite-time singularities for broad classes of solutions are
given. The existence of a continuum of multifinger fixed points and its
dynamical implications are discussed. The main conclusion is that exact
zero-surface tension solutions taken in a global sense as families of
trajectories in phase space spanning a sufficiently large set of initial
conditions, are unphysical because the multifinger fixed points are
nonhyperbolic, and an unfolding of them does not exist within the same class of
solutions. Hyperbolicity (saddle-point structure) of the multifinger fixed
points is argued to be essential to the physically correct qualitative
description of finger competition. The restoring of hyperbolicity by surface
tension is discussed as the key point for a generic Dynamical Solvability
Scenario which is proposed for a general context of interfacial pattern
selection.Comment: 3 figures added, major rewriting of some sections, submitted to Phys.
Rev.
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