Three-Body Elastic and Inelastic Scattering at Intermediate Energies

The Faddeev equation for three-body scattering at arbitrary energies is formulated in momentum space and directly solved in terms of momentum vectors without employing a partial wave decomposition. For identical bosons this results in a three-dimensional integral equation in five variables, magnitudes of relative momenta and angles. The cross sections for both elastic and breakup processes in the intermediate energy range up to about 1 GeV are calculated based on a Malfliet-Tjon type potential, and the convergence of the multiple scattering series is investigated.Comment: Talk at the 18th International IUPAP Conference on Few-Body Problems in Physics, Aug. 21-26, 2006, Santos, Brazi

Spurious detection of phase synchronization in coupled nonlinear oscillators

Coupled nonlinear systems under certain conditions exhibit phase synchronization, which may change for different frequency bands or with presence of additive system noise. In both cases, Fourier filtering is traditionally used to preprocess data. We investigate to what extent the phase synchronization of two coupled R\"{o}ssler oscillators depends on (1) the broadness of their power spectrum, (2) the width of the band-pass filter, and (3) the level of added noise. We find that for identical coupling strengths, oscillators with broader power spectra exhibit weaker synchronization. Further, we find that within a broad band width range, band-pass filtering reduces the effect of noise but can lead to a spurious increase in the degree of synchronization with narrowing band width, even when the coupling between the two oscillators remains the same.Comment: 4 pages,6 figure

Effect of nonlinear filters on detrended fluctuation analysis

We investigate how various linear and nonlinear transformations affect the scaling properties of a signal, using the detrended fluctuation analysis (DFA). Specifically, we study the effect of three types of transforms: linear, nonlinear polynomial and logarithmic filters. We compare the scaling properties of signals before and after the transform. We find that linear filters do not change the correlation properties, while the effect of nonlinear polynomial and logarithmic filters strongly depends on (a) the strength of correlations in the original signal, (b) the power of the polynomial filter and (c) the offset in the logarithmic filter. We further investigate the correlation properties of three analytic functions: exponential, logarithmic, and power-law. While these three functions have in general different correlation properties, we find that there is a broad range of variable values, common for all three functions, where they exhibit identical scaling behavior. We further note that the scaling behavior of a class of other functions can be reduced to these three typical cases. We systematically test the performance of the DFA method in accurately estimating long-range power-law correlations in the output signals for different parameter values in the three types of filters, and the three analytic functions we consider.Comment: 12 pages, 7 figure

Hooge's Constant of Carbon Nanotube Field Effect Transistors

The 1/f noise in individual semiconducting carbon nanotubes (s-CNT) in a field effect transistor configuration has been measured in ultra-high vacuum and following exposure to air. The amplitude of the normalized current spectral noise density is independent of source-drain current, indicating the noise is due to mobility rather than number fluctuations. Hooge's constant for s-CNT is found to be 9.3 plus minus 0.4x10^-3. The magnitude of the 1/f noise is substantially degreased by exposing the devices to air

Integrability of the critical point of the Kagom\'e three-state Potts mode

The vicinity of the critical point of the three-state Potts model on a Kagom\'e lattice is studied by mean of Random Matrix Theory. Strong evidence that the critical point is integrable is given.Comment: 1 LaTex file + 3 eps files 7 page

Influence of the indirect restoration design on the fracture resistance: a finite element study

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Absorbate-Induced Piezochromism in a Porous Molecular Crystal

Atmospherically stable porous frameworks and materials are interesting for heterogeneous solid–gas applications. One motivation is the direct and selective uptake of pollutant/hazardous gases, where the material produces a measurable response in the presence of the analyte. In this report, we present a combined experimental and theoretical rationalization for the piezochromic response of a robust and porous molecular crystal built from an extensively fluorinated trispyrazole. The electronic response of the material is directly determined by analyte uptake, which provokes a subtle lattice contraction and an observable bathochromic shift in the optical absorption onset. Selectivity for fluorinated absorbates is demonstrated, and toluene is also found to crystallize within the pore. Furthermore, we demonstrate the application of electronic structure calculations to predict a physicochemical response, providing the foundations for the design of electronically tunable porous solids with the chemical properties required for development of novel gas-uptake media

Examining the role of socioeconomic deprivation in ethnic differences in sexually transmitted infection diagnosis rates in England: evidence from surveillance data

Differences by ethnic group in STI diagnosis rates have long been recognized in England. We investigated whether these may be explained by ethnic disparities in socioeconomic deprivation (SED). Data on all diagnoses made in sexual health clinics in England in 2013 were obtained from the mandatory STI surveillance system. Poisson regression was used to calculate incidence rate ratios (IRRs) of STIs, by ethnicity, with and without adjustment for index of multiple deprivation (IMD) a measure of area-level deprivation. Unadjusted IRRs (95% confidence intervals) were highest for gonorrhoea [8·18 (7·77-8·61) and 5·76 (5·28-6·29)] and genital herpes [4·24 (3·99-4·51) and 3·58 (3·23-3·98)] for people of black Caribbean and non-Caribbean/non-African black ethnicity and IRRs were highest for syphilis [8·76 (7·97-9·63)] and genital warts [2·23 (2·17-2·29)] for people of non-British/non-Irish white ethnicity compared to white British ethnicity. After adjustment for IMD, IRRs for gonorrhoea [5·76 (5·47-6·07)] and genital herpes [3·73 (3·50-3·97)] declined but remained highest for black Caribbeans and IRRs for syphilis [7·35 (6·68-8·09)] and genital warts [2·10 (2·04-2·16)] declined but remained highest for non-British/non-Irish white compared to white British. In England, ethnic disparities in STI diagnosis rates are partially explained by SED, but behavioural and contextual factors likely contribute. Clinic and community-based interventions should involve social peer networks to ensure they are targeted and culturally sensitive

Evolutionary game of coalition building under external pressure

We study the fragmentation-coagulation (or merging and splitting) evolutionary control model as introduced recently by one of the authors, where $N$ small players can form coalitions to resist to the pressure exerted by the principal. It is a Markov chain in continuous time and the players have a common reward to optimize. We study the behavior as $N$ grows and show that the problem converges to a (one player) deterministic optimization problem in continuous time, in the infinite dimensional state space