The intermittent behavior of a second-order non-linear non-autonomous oscillator

The experimental time-series produced by a second-order non-linear, non-autonomous, closed-loop electronic circuit were recorded and subsequently evaluated. The correlation and embedding dimensions, as well as the corresponding Kolmogorov entropies of the oscillating system, have been numerically calculated and compared to the corresponding Lyapunov exponents.     

K X-ray satellites of uranium bombarded with 500 MeV neon

K X-ray satellite spectra produced during the bombardment of uranium with 500 MeV neon, have been investigated with a high resolution crystal spectrometer. The experimental results are compared with theoretical predictions for vacancy production computed in the semiclassical separate atom perturbation theory and corrected forL subshell coupling and electron transfer from targetL shell into projectileK shell. The agreement between theory and experiment is rather good. It turns out, that the reduction ofL vacancy production due toL subshell coupling is essentially compensated by theL electron transfer from target to projectile. The present work is an extension of a previous study of theK α₁ satellite spectra of tantalum bombarded with 403 MeV nitrogen.     

A framework of incorporating confidence levels to deal with uncertainty in pairwise comparisons

Central European Journal of Operations Research - Pairwise comparison is a key ingredient in multi-criteria decision analysis. The method is based on a set of comparisons conducted by a group of...     

Iron(II) and iron(III) complexes of 2,4-dithiobiuret

Summary Ferrous and ferric complexes of 2,4-dithiobiuret (Dtb) of the type Fe(Dtb)_m Xn where m, n = 1-3, and X = CI^–, Br^–, I^– and SO ₄ ^2– , and a neutral Fe(Dtb-H)2 complex have been synthesized and characterised by elemental analyses, magnetic susceptibility, i.r., electronic and Mössbauer spectroscopic studies. From its i.r. spectrum Dtb was found to act as a S,S-coordinating bidentate chelate. The magnetic moment, electronic and Massbauer spectra are consistent with a low spin distorted octahedral structure for the ferric complexes and a high spin form for ferrous complexes.     

Homophily and polarization in the age of misinformation

The World Economic Forum listed massive digital misinformation as one of the main threats for our society. The spreading of unsubstantiated rumors may have serious consequences on public opinion such as in the case of rumors about Ebola causing disruption to health-care workers. In this work we target Facebook to characterize information consumption patterns of 1.2?M Italian users with respect to verified (science news) and unverified (conspiracy news) contents. Through a thorough quantitative analysis we provide important insights about the anatomy of the system across which misinformation might spread. In particular, we show that users’ engagement on verified (or unverified) content correlates with the number of friends having similar consumption patterns (homophily). Finally, we measure how this social system responded to the injection of 4,709 false information. We find that the frequent (and selective) exposure to specific kind of content (polarization) is a good proxy for the detection of homophile clusters where certain kind of rumors are more likely to spread.     

The solution space of the unitary matrix model string equation and the Sato Grassmannian

The space of all solutions to the string equation of the symmetric unitary one-matrix model is determined. It is shown that the string equation is equivalent to simple conditions on pointsV ₁ andV ₂ in the big cell Gr⁽⁰⁾ of the Sato Grassmannian Gr. This is a consequence of a well-defined continuum limit in which the string equation has the simple form matrices of differential operators. These conditions onV ₁ andV ₂ yield a simple system of first order differential equations whose analysis determines the space of all solutions to the string equation. This geometric formulation leads directly to the Virasoro constraintsL _n (n0), whereL _n annihilate the two modified-KdV -functions whose product gives the partition function of the Unitary Matrix Model.     

Cu-Kβ radiation inelastically scattered from beryllium and boron interferenced by K-MM radiative Auger transitions

High-resolution spectroscopic analysis of inelastically scattered X-rayK radiation of Cu from polycrystalline Be and B shows some peculiar structure in the region of the inelastically scattered radiation. Coherent scattering of the low-energy satellite structure of the primary Cu-K lines, which extends in the same low-energy region, contaminates the inelastic spectrum and may be responsible for the observed structure. This parasitic elastically scattered radiation contributes to the background lying under the X-ray Raman scattering data and its knowledge is necessary for the correct evaluation of the Raman spectrum.     

Pionic hydrogen and deuterium

The ground-state level shifts and broadenings of the hydrogen isotopes caused by the strong interaction have been redetermined by using a high-resolution crystal spectrometer. An additional measurement of muonic hydrogen reveals properties of the de-excitation cascade of such electrically neutral exotic atoms, in particular Coulomb de-excitation, the understanding of which is essential for the analysis of the hadronic-atom data.     

The relaxed Newton method derivative: Its dynamics and non-linear properties

The dynamic behaviour of the one-dimensional family of maps f(x)=_c2[(a−1)x+_c1]^{−λ/(α−1)}$f\left(x\right)=c_2{[(a-1)x+c_1]}^{-\lambda /(\alpha -1)}$ is examined, for representative values of the control parameters a,_c1$a,c_1$, _c2$c_2$ and λ$\lambda$. The maps under consideration are of special interest, since they are solutions of the relaxed Newton method derivative being equal to a constant a$a$. The maps f(x)$f\left(x\right)$ are also proved to be solutions of a non-linear differential equation with outstanding applications in the field of power electronics. The recurrent form of these maps, after excessive iterations, shows, in an _xn$x_n$ versus λ$\lambda$ plot, an initial exponential decay followed by a bifurcation. The value of λ$\lambda$ at which this bifurcation takes place depends on the values of the parameters a,_c1$a,c_1$ and _c2$c_2$. This corresponds to a switch to an oscillatory behaviour with amplitudes of f(x)$f\left(x\right)$ undergoing a period doubling. For values of a$a$ higher than 1 and at higher values of λ$\lambda$ a reverse bifurcation occurs. The corresponding branches converge and a bleb is formed for values of the parameter _c1$c_1$ between 1 and 1.20. This behaviour is confirmed by calculating the corresponding Lyapunov exponents.