Search results for "Amplitude"
showing 10 items of 1169 documents
Single-energy partial wave analysis for π0 photoproduction on the proton with fixed- t analyticity imposed
2019
High-precision data of the $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}p$ reaction from its threshold up to $W=1.9\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}$ have been used in order to perform a single-energy partial-wave analysis with minimal model dependence. Continuity in energy was achieved by imposing constraints from fixed-$t$ analyticity in an iterative procedure. Reaction models were only used as starting point in the very first iteration. We demonstrate that, with this procedure, partial-wave amplitudes can be obtained which show only a minimal dependence on the initial model assumptions.
Changes in the objective amplitude of accommodation with pupil size.
2014
PURPOSE We evaluate the effect of pupil size on objectively measured amplitude of accommodation (AA). METHODS Pupil diameter and wavefront aberrometry were obtained in 15 eyes when stimulus swept across the range of clear vision in steps of 0.5 diopters. Wavefront refraction techniques were used to compute objective AA as the maximum refractive change. Measurements were obtained monocularly under low and high ambient room lighting conditions with a fixed luminance of the fixation target. Amplitude of accommodation computations were performed taking into account just paraxial rays (paraxial AA) or including the effects of the change of spherical aberration during accommodation (minRMS AA). R…
Influence of Whole-Body Dynamics on 15N PISEMA NMR Spectra of Membrane Proteins: A Theoretical Analysis
2009
AbstractMembrane proteins and peptides exhibit a preferred orientation in the lipid bilayer while fluctuating in an anisotropic manner. Both the orientation and the dynamics have direct functional implications, but motions are usually not accessible, and structural descriptions are generally static. Using simulated data, we analyze systematically the impact of whole-body motions on the peptide orientations calculated from two-dimensional polarization inversion spin exchange at the magic angle (PISEMA) NMR. Fluctuations are found to have a significant effect on the observed spectra. Nevertheless, wheel-like patterns are still preserved, and it is possible to determine the average peptide til…
Molecular dynamics simulation of carboxy-myoglobin embedded in a trehalose-water matrix
2001
AbstractWe report on a molecular dynamics (MD) simulation of carboxy-myoglobin (MbCO) embedded in a water-trehalose system. The mean square fluctuations of protein atoms, calculated at different temperatures in the 100–300K range, are compared with those from a previous MD simulation on an H2O-solvated MbCO and with experimental data from Mössbauer spectroscopy and incoherent elastic neutron scattering on trehalose-coated MbCO. The results show that, for almost all the atomic classes, the amplitude of the nonharmonic motions stemming from the interconversion among the protein’s conformational substates is reduced with respect to the H2O-solvated system, and their onset is shifted toward hig…
Turbulence structure and implications in exchange processes in high-amplitude vegetated meanders: Experimental investigation
2018
Aquatic plants in rivers interact with flow and exert an important role in maintaining suitable habitat and ecological equilibrium. Understanding turbulence structure in the presence of vegetation is important with respect to environmental processes, such as sediment transport and mixing of transported quantities. Literature indicates that mass and momentum exchanges in the presence of vegetation are strongly influenced by the sequence of coherent structures which form between vegetated and non-vegetated zones. In the present paper we investigate turbulence structure and coherent motion in high-curvature channels with submerged vegetation. The analysis is performed with the aid of detailed …
A quark model study of strong decays ofX(3915)
2017
Strong decays of are analyzed from two quark model descriptions of , a conventional one in terms of the Cornell potential and an unconventional one from a generalized screened potential. We conclude that the experimental suppression of the OZI allowed decay might be explained in both cases due to the momentum dependence of the decay amplitude. However, the experimental significance of the OZI forbidden decay could favor an unconventional description.
Multipactor RF Breakdown in Coaxial Transmission Lines With Digitally Modulated Signals
2016
The aim of this paper is the study of the RF multipactor breakdown in coaxial transmission lines excited by a single carrier with a digitally modulated signal. Employing an in-house developed code, numerical simulations are performed to determine the RF multipactor voltage threshold for several digitally modulated signals under different modulations schemes: quadrature phase-shift keying, 16-quadrature amplitude modulation, 16-amplitude and phase-shift keying, and 32-amplitude and phase-shift keying. Moreover, a coarse method based on the envelope integration to determine the RF multipactor voltage threshold when involving arbitrary digital modulations is also presented. These results are a…
FINITE-SIZE CORRECTIONS TO CORRELATION FUNCTION AND SUSCEPTIBILITY IN 2D ISING MODEL
2006
Transfer matrix calculations of the critical two-point correlation function in 2D Ising model on a finite-size [Formula: see text] lattice with periodic boundaries along 〈11〉 direction are extended to L = 21. A refined analysis of the correlation function in 〈10〉 crystallographic direction at the distance r = L indicates the existence of a nontrivial finite-size correction of a very small amplitude with correction-to-scaling exponent ω < 2 in agreement with our foregoing study for L ≤ 20. Here we provide an additional evidence and show that amplitude a of the multiplicative correction term 1 + aL-ωis about -3.5·10-8if ω = 1/4 (the expected value). We calculate also the susceptibility for…
Algorithms for the ROD DSP of the ATLAS Hadronic Tile Calorimeter
2007
In this paper we present the performance of two algorithms currently running in the Tile Calorimeter Read-Out Driver boards for the commissioning of ATLAS. The first algorithm presented is the so called Optimal Filtering. It reconstructs the deposited energy in the Tile Calorimeter and the arrival time of the data. The second algorithm is the MTag which tags low transverse momentum muons that may escape the ATLAS muon spectrometer first level trigger. Comparisons between online (inside the Read-Out Drivers) and offline implementations are done with an agreement around 99% for the reconstruction of the amplitude using the Optimal Filtering algorithm and a coincidende of 93% between the offli…
Discerning the Origins of the Amplitude Fluctuations in Dynamic Raman Nanospectroscopy
2012
International audience; We introduce a novel experimental and analytical method for discerning rare surface-enhanced Raman scattering (SERS) events observable at the nanoscale. We show that the kinetics of the Raman activity recorded on an isolated nanostructure is punctuated by intense and rare events of large amplitude and spectral variations. The fluctuations of thousands of SERS spectra were analyzed statistically in terms of power density functions, and the occurrence of the rare events was quantified by a wavenumber statistics. Our analysis enables one to extract valuable and unique spectroscopic signature of Raman variations usually hidden in time-average or space-average measurement…