This is a unique book that presents rigorous mathematical results on Fermi-Pasta-Ulam lattices, a field of great interest in nonlinear analysis, nonlinear science, mathematical physics, etc. It ...considers travelling waves and time periodic oscillations in infinite Fermi-Pasta-Ulam lattices, which are not necessarily spatially homogenous. Similar systems, infinite chains of linearly coupled nonlinear oscillators, are also discussed. The book is self-contained and includes a number of open problems, making it suitable for use in a course for graduate students.
The full ATLAS run 2 dataset with a time-integrated luminosity of 139 fb−1 in the diboson and dilepton channels is used to probe benchmark models with extended gauge sectors: the E6-motivated grand ...unification models, the left-right symmetric model, and the sequential standard model extended gauge model (EGM). These all predict neutral Z′ vector bosons, decaying into lepton pairs ℓℓ or into electroweak gauge boson pairs WW, where one W in turn decays semileptonically. The 95% C.L. exclusion limits on the Z′ resonance production cross section times the branching ratio to electroweak gauge boson pairs and to lepton pairs in the mass range of ∼ 1 to 6 TeV are converted to constraints on the Z−Z′ mixing parameter and the heavy resonance mass. We present exclusion regions on the parameter space of the Z′ which are significantly extended compared to those obtained from the previous analyses performed with LHC data collected at 7 and 8 TeV in run 1 as well as at 13 TeV in run 2 at a time-integrated luminosity of 36.1 fb−1 and are the most stringent bounds to date. Also presented, from a similar analysis of electrically charged W′ bosons arising in the EGM, which can decay through W′ → WZ and W′ → ℓν, are limits on the W−W′ mixing parameter and the charged W′ vector boson mass.
•Mg-Zn ferrites prepared by autocombustion, co-precipitation, spray pyrolysis.•Influence of structural features on magnetic properties of ferrites is determined.•The highest magnetization is achieved ...for Mg0.5Zn0.5Fe2O4 nanoparticles.
Structural characteristics and magnetic properties of MgxZn1–xFe2O4 (x = 0.25; 0.5; 0.7) nanomaterials prepared by autocombustion, co-precipitation and spray pyrolysis methods were studied. Different characterization techniques are used to study the structural formation of the generated nanoparticles, namely X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM), infrared spectroscopy (FT-IR) and vibrating sample magnetometery (VSM). In case of citrate autocombustion and co-precipitation methods, the magnetization goes through a maximum at Mg0.5Zn0.5Fe2O4 composition, while the dependence on the composition is subtle for spray pyrolysis. An increase in temperature and duration of heat treatment during the synthesis process leads to a particle size growth and to a cation redistribution between spinel sub-lattices. These resulted in a significant increase in the specific magnetization of the particles generated by citrate autocombustion method. The nanoparticles synthesized by co-precipitation method exhibit superparamagnetic behavior with no coercivity at room temperature. Nonetheless, the materials prepared by spray pyrolysis and citrate autocombustion methods are found to possess small coercivity of 30–80 Oe. The highest specific magnetization at room temperature is referring to Mg0.5Zn0.5Fe2O4 nanoparticles obtained by citrate autocombustion method (30 emu/g). The revealed correlations can be used to synthesize spinel ferrite nanoparticles with well-defined collective properties for a wide spectrum of applications.
The study of electroweak boson pair production provides a powerful test of the spontaneously broken gauge symmetry of the standard model (SM) and can be used to search for new phenomena beyond the ...SM. Extra neutral vector bosons Z′ decaying to charged gauge vector boson pairs W+W− are predicted in many scenarios of new physics, including models with an extended gauge sector. The diboson production allows us to place stringent constraints on the Z−Z′ mixing factor ξ and Z′ mass, MZ′. We present the Z′ exclusion region in the ξ−MZ′ plane for the first time by using data comprised of pp collisions at s=13 TeV and recorded by the ATLAS and CMS detectors at the CERN LHC, with integrated luminosities of 36.1 and 35.9 fb−1, respectively. The exclusion region has been significantly extended compared to that obtained from the previous analysis performed with Tevatron data as well as with LHC data collected at 7 and 8 TeV. Also, we found that these constraints on the Z−Z′ mixing factor are more severe than those derived from the global analysis of electroweak data. Further improvement on the constraining of this mixing can be achieved from the analysis of data to be collected at higher luminosity.
•The kinetics of nucleation in a superheated methane–nitrogen solution was investigated.•Measurements has been made at two values of pressure and full range of composition.•The mean life time method ...has been used.•The results of experiments have been compared with classical nucleation theory.
The mean life time method has been used to investigate the kinetics of nucleation in a superheated methane–nitrogen solution. Measurements have been made in the range of nucleation rates J = (1.2·104–1.6·108) m−3s−1. Temperature dependences of the nucleation rate have been obtained for seven compositions of the solution at pressures p = 1.0 and 1.6 MPa. The results of the experiments have been compared with classical nucleation theory (CNT). In contrast to pure methane and hydrogen, where superheating temperatures achieved by experiment are lower than their theoretical values, in methane–nitrogen solutions the opposite behavior is found. Close to the equimolecular composition limiting superheatings of solutions exceed theoretical values by (1.2–1.6) K. Possible reasons for the disagreement between CNT and experiment (size dependence of the surface tension of critical bubbles, bypassing the saddle point of the activation barrier, etc) are analyzed.
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The aim of this research was to prepare magnesium ferrite (MgFe2O4) magnetic nanoparticles and to investigate their sorption characteristics towards Mn2+, Co2+, Ni2+, Cu2+ ions in aqueous solution. ...MgFe2O4 was synthesized by glycine-nitrate combustion method and was characterized by low crystallinity with crystallite size of 8.2 nm, particle aggregates of 13–25 nm, BET surface area of 14 m2/g and pore size of 8.0 nm. Sorption properties of MgFe2O4 towards Mn2+, Co2+, Ni2+, Cu2+ ions were studied using one-component model solutions and found to be dependent on metal ions concentration, contact time, pH and conditions of regeneration experiment. The highest sorption capacity of MgFe2O4 was detected towards Co2+ (2.30 mmol g1) and Mn2+ (1.56 mmol g−1) and the lowest towards Ni2+ (0.89 mmol g−1) and Cu2+ (0.46 mmol g−1). It was observed that sorption equilibrium occurs very quickly within 20–60 min. The pHzpc of sorbent was calculated to be 6.58. At studied pH interval (3.0–7.0) the sorption capacity of MgFe2O4 was not significantly affected. Regeneration study showed that the metal loaded sorbent could be regenerated by aqueous solution of 10−3 M MgCl2 at pH 6.0 within 120 min of contact time. Regeneration test suggested that MgFe2O4 magnetic sorbent can be efficiently used at least for four adsorption-desorption cycles. The high sorption properties and kinetics of toxic metal ion sorption indicates good prospects of developed sorbent in practice for wastewater treatment.
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•MgFe2O4 nanoparticles as a magnetic sorbent was synthesized by glycine-nitrate method.•The prepared sorbent showed high adsorption capacity (2.30 mmol g−1) for Co2+.•The sorption equilibrium achieved very quickly within 20–60 min.•Firstly MgCl2 solution was proposed for MgFe2O4 sorbent regeneration.•MgFe2O4 sorbent can be efficiently used in adsorption-desorption cycles.
New neutral vector bosons Z′ decaying to charged gauge boson pairs W+W− are predicted in many scenarios of new physics, including models with an extended gauge sector such as E6, left-right symmetric ...ZLRS′ and the sequential standard model ZSSM′. For these benchmark models we calculate and present theoretical expectations for different values of the Z′ mass M2 and mixing parameter ξ. Our results are based on the narrow width approximation which allows for the making of a convenient comparison of the experiment to theoretical benchmark models. The diboson production allows for the placement of stringent constraints on the Z−Z′ mixing angle and the Z′ mass, which we determine by using data from pp collisions at s=13 TeV recorded by the ATLAS detector at the CERN LHC, with integrated luminosity of ∼36 fb−1. By comparing the experimental limits to the theoretical predictions for the total cross section of Z′ resonant production and its subsequent decay into W+W− pairs, we show that the derived constraints on the mixing angle for the benchmark models are of the order of a few ×10−4, i.e., greatly improved with respect to those derived from the global analysis of electroweak data. We combine the limits derived from diboson production data with those obtained from the Drell–Yan process in order to significantly extend the exclusion region in the M2−ξ parameter plane. Also, we demonstrate that further improvement on the constraining of this mixing can be achieved through analysis of the full set of Run II data.
A numerical-analytical solution to the “effective modulus problem” of transversally isotropic porous ceramics is obtained, taking into account its initial stressed state and the ellipsoidal shape of ...oriented pores of various connectivity based on the solution of the associated stochastic boundary value problem of electroelasticity of composite mechanics using the Green’s function method. A numerical calculation of the initial and resulting values of the effective piezoelectric modulus of porous piezoceramics (PZT-4) was carried out depending on the values of the volume fraction, shape parameter and connectivity of ellipsoidal, in particular: spherical, disk or tunnel pores, taking into account the initial stressed state of the porous piezoceramics due to its initial axisymmetric deformation. Characteristic values of the volume fraction of spherical and disk pores are identified, taking into account their connections, at which the sign of the numerical values of the initial effective piezoelectric modulus changes with respect to the corresponding module of PZT-4 monolithic ceramics. The values of the volume fraction, shape parameter and type of pore connectivity at which the maximum gradients of the linear dependence of the values of the resulting piezoelectric modulus of porous piezoceramics on its initial macrodeformations are realized are determined. An analysis of graphs of continuous dependences of the initial and resulting values of the effective piezoelectric modulus on the pore shape parameter is given for various cases of their volumetric content, connectivity and axisymmetric initial deformations of porous piezoceramics.
The cytochrome P450 (CYP) superfamily is a diverse and important enzyme family, playing a central role in chemical defense and in synthesis and metabolism of major biological signaling molecules. The ...CYPomes of four cnidarian genomes (Hydra vulgaris, Acropora digitifera, Aurelia aurita, Nematostella vectensis) were annotated; phylogenetic analyses determined the evolutionary relationships amongst the sequences and with existing metazoan CYPs. 155 functional CYPs were identified and 90 fragments. Genes were from 24 new CYP families and several new subfamilies; genes were in 9 of the 12 established metazoan CYP clans. All species had large expansions of clan 2 diversity, with H. vulgaris having reduced diversity for both clan 3 and mitochondrial clan. We identified potential candidates for xenobiotic metabolism and steroidogenesis. That each genome contained multiple, novel CYP families may reflect the large evolutionary distance within the cnidarians, unique physiology in the cnidarian classes, and/or different ecology of the individual species.
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