629 research outputs found
Mechanizacja budowy linii kablowych. Część I. Przegląd Zagadnień Łączności, 1963, nr 7 (22)
Opracowania na podstawie artykułó
Telekomunikacyjne linie kablowe. Część II. Przegląd Zagadnień Łączności, 1963, nr 8 (23)
Opracowania na podstawie artykułó
Risk of climate-induced damage in historical textiles
Eleven wool and silk historic textiles and two modern artist's canvases were examined to determine their water vapour adsorption, moisture dimensional response and tensile behaviour. All the textiles showed a similar general pattern of moisture response. A rise in ambient relative humidity (RH) from dry conditions produced expansion of a textile until a certain critical RH level after which a contraction occurred to a greater or lesser degree depending on the yarn crimp and the weave geometry. The largest expansion recorded between the dry state and 80% RH was 1.2 and 0.9% for wool and silk textiles, respectively. The largest shrinkage of 0.8% at high RH range was experienced by a modern linen canvas. Two potential damage mechanisms related to the moisture response of the textiles—stress building as a result of shrinkage of the textile restrained in its dimensional response and the fretting fatigue when yarns move with friction one against another—were found insignificant in typical textile display environments unless the textiles are severely degraded or excessively strained in their mounting
axial form factor from bubble chamber experiments
A careful reanalysis of both Argonne National Laboratory and Brookhaven
National Laboratory data for weak single pion production is done. We consider
deuteron nuclear effects and normalization (flux) uncertainties in both
experiments. We demonstrate that these two sets of data are in good agreement.
For the dipole parametrization of , we obtain , GeV. As an application we present the discussion of
the uncertainty of the neutral current 1 production cross section,
important for the T2K neutrino oscillation experiment.Comment: 16 pages, 8 figures, 2 table
Probing the mechanisms of electron capture dissociation mass spectrometry with nitrated peptides
Previously we have shown that the presence of 3-nitrotyrosine within a peptide sequence severely depletes the peptide backbone fragments typically observed following electron capture dissociation (ECD) mass spectrometry. Instead, ECD of nitrated peptides is characterised by abundant losses of small neutrals (hydroxyl radicals, water and ammonia). Here, we investigate the origin of ammonia loss by comparing the ECD behaviour of lysine- and arginine-containing nitrated peptides, and their N-acetylated counterparts, and nitrated peptides containing no basic amino acid residues. The results reveal that ammonia loss derives from the N-terminus of the peptides, however, the key finding of this work is the insight provided into the hierarchy of various proposed ECD mechanisms: the Utah-Washington mechanism, the electron predator mechanism and the Oslo mechanism
Geometrical Aberration Suppression for Large Aperture Sub-THz Lenses
Advanced THz setups require high performance optical elements with large numerical apertures and small focal lengths. This is due to the high absorption of humid air and relatively low efficiency of commercially available detectors. Here, we propose a new type of double-sided sub-THz diffractive optical element with suppressed geometrical aberration for narrowband applications (0.3 THz). One side of the element is designed as thin structure in non-paraxial approach which is the exact method, but only for ideally flat elements. The second side will compensate phase distribution differences between ideal thin structure and real volume one. The computer-aided optimization algorithm is performed to design an additional phase distribution of correcting layer assuming volume designing of the first side of the element. The experimental evaluation of the proposed diffractive component created by 3D printing technique shows almost two times larger performance in comparison with uncorrected basic diffractive lens
Statistics of non-linear stochastic dynamical systems under L\'evy noises by a convolution quadrature approach
This paper describes a novel numerical approach to find the statistics of the
non-stationary response of scalar non-linear systems excited by L\'evy white
noises. The proposed numerical procedure relies on the introduction of an
integral transform of Wiener-Hopf type into the equation governing the
characteristic function. Once this equation is rewritten as partial
integro-differential equation, it is then solved by applying the method of
convolution quadrature originally proposed by Lubich, here extended to deal
with this particular integral transform. The proposed approach is relevant for
two reasons: 1) Statistics of systems with several different drift terms can be
handled in an efficient way, independently from the kind of white noise; 2) The
particular form of Wiener-Hopf integral transform and its numerical evaluation,
both introduced in this study, are generalizations of fractional
integro-differential operators of potential type and Gr\"unwald-Letnikov
fractional derivatives, respectively.Comment: 20 pages, 5 figure
Bosonic Field Propagators on Algebraic Curves
In this paper we investigate massless scalar field theory on non-degenerate
algebraic curves. The propagator is written in terms of the parameters
appearing in the polynomial defining the curve. This provides an alternative to
the language of theta functions. The main result is a derivation of the third
kind differential normalized in such a way that its periods around the homology
cycles are purely imaginary. All the physical correlation functions of the
scalar fields can be expressed in terms of this object. This paper contains a
detailed analysis of the techniques necessary to study field theories on
algebraic curves. A simple expression of the scalar field propagator is found
in a particular case in which the algebraic curves have internal symmetry
and one of the fields is located at a branch point.Comment: 26 pages, TeX + harvma
On two weak CC Delta production models
We perform a detail analysis of two models of neutrino CC Delta production on
free nucleons. First model is a standard one based on nucleon-Delta transition
current with several form-factors. Second model is a starting point for a
construction of Marteau model with sophisticated analytical computations of
nuclear effects. We conclude that both models lead to similar results.Comment: 9 pages, includes 9 figures, accepted for publication in J. Phys.
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