Search

The hexagonal perovskite Ba5 In2Al2ZrO13 and In3+-doped phase Ba5 In2.1Al2Zr0.9O12.95 were prepared by the solid-state synthesis method. The introduction of indium in the Zr-sublattice was accompanied by an increase in the unit cell parameters: a = 5.967 Å, c = 24.006 Å vs. a = 5.970 Å, c = 24.011 Å for doped phase (space group of P63 /mmc). Both phases were capable of incorporating water from the gas phase. The ability of water incorporation was due to the presence of oxygen deficient blocks in the structure, and due to the introduction of oxygen vacancies during doping. According to thermogravimetric (TG) measurements the compositions of the hydrated samples corresponded to Ba5 In2Al2ZrO12.7 (OH)0.6 and Ba5 In2.1Al2Zr0.9O12.54 (OH)0.82. The presence of different types of OH−-groups in the structure, which participate in different hydrogen bonds, was confirmed by infrared (IR) investigations. The measurements of bulk conductivity by the impedance spectroscopy method showed that In3+-doping led to an increase in conductivity by 0.5 order of magnitude in wet air (pH2O = 1.92·10−2 atm); in this case, the activation energies decreased from 0.27 to 0.19 eV. The conductivity−pO2 measurements showed that both the phases were dominant proton conductors at T < 500◦C in wet conditions. The composition Ba5 In2.1Al2Zr0.9O12.95 exhibited a proton conductivity ~10−4 S·cm−1 at 500◦C. The analysis of partial (O2−, H+, h•) conductivities of the investigated phases has been carried out. Both phases in dry air (pH2O = 3.5·10−5 atm) showed a mixed (oxygen-ion and hole) type of conductivity. The obtained results indicated that the investigated phases of Ba5 In2Al2ZrO13 and Ba5 In2.1Al2Zr0.9O12.95 might be promising proton-conducting oxides in the future applications in electrochemical devices, such as solid oxide fuel cells. Further modification of the composition and search for the optimal dopant concentrations can improve the H+-conductivity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. Russian Science Foundation, RSF: 22-23-20003 Funding: This research was supported by the Russian Science Foundation and Government of Sverdlovsk region, Joint Grant 22-23-20003 https://rscf.ru/en/project/22-23-20003/.

We have proposed a new canonical-isokinetic ensemble for efficient sampling of conformational space in molecular dynamics (MD) simulations which leads to the optimised isokinetic Nosé-Hoover (OIN) chain algorithm for atomic and molecular systems. We applied OIN to multiple time step (MTS) MD simulations of the rigid and flexible models of water to demonstrate its advantage over the standard canonical, isokinetic and canonical-isokinetic ensembles. With the stabilising effect of OIN thermostatting in MTS-MD, gigantic outer time steps up to picoseconds can be employed to accurately calculate equilibrium and conformational properties. Furthermore, we developed the atomic version of OIN for MTS-MD of a biomolecule in a solvent potential of mean force obtained at sequential MD steps by using the molecular theory of solvation, aka three-dimensional reference interaction site model with the Kovalenko-Hirata closure (3D-RISM-KH). The solvation forces are obtained analytically by converging the 3D-RISM-KH integral equations once per several OIN outer time steps, and are calculated in between by using solvation force-coordinate extrapolation (SFCE) in the subspace of previous successive solutions to 3D-RISM-KH. For illustration, we applied the multiscale OIN/SFCE/3D-RISM-KH algorithm to a fully flexible model of alanine dipeptide in aqueous solution. Although the computational rate of solvent sampling in OIN/SFCE/3D-RISM-KH is already 20 times faster than standard MD with explicit solvent, further substantial acceleration of sampling stems from making solute evolution steps in a statistically averaged potential of mean force obtained from 3D-RISM-KH. The latter efficiently samples the phase space for essential events with rare statistics such as exchange and localisation of solvent and ligand molecules in confined spaces, pockets and at binding sites of the solute macromolecule, as distinct from MD with explicit solvent which requires enormous computational time and number of steps in such cases. © 2013 Taylor & Francis Group, LLC.

This study focuses on the thermal-diffusive oscillations of the full spectrum of co-flow laminar flames-from premixed to non-premixed through partially premixed flames for Lewis numbers sufficiently greater than unity. A premixedness parameter is identified using the analytical solution to the mixing field downstream of a splitter plate. Different premixedness levels ranging from zero (fully non-premixed) to unity (fully premixed) are then used as Dirichlet data for inlet concentrations of the reactants to the flame. The initial value problem is numerically solved by adopting a thermo-diffusive model and single-step finite rate chemical reaction and using higher-order compact schemes. A thumb-shaped region in the Damk�hler number - premixedness parameter space is identified as corresponding to limit cycle oscillations of the flame. This fills the gap between what is reported for the pulsating instability of non-premixed edge flames recently and fully premixed flames earlier. The thumb-shaped region enlarges with increase in the Lewis number in the range of 1.5-1.7, with marked increase in the oscillatory amplitude of the total heat release. A subcritical Hopf bifurcation is seen to occur at the boundary of this region in the above parametric space. The mechanism of oscillations is studied: hysteresis is found between the upstream and downstream propagation of the flame due to the thermal-diffusive imbalance. The oscillations are plotted in the phase space of the domain-integrated mass and heat diffusive fluxes of and to the reactants. The area of the limit cycle peaks at a particular Damk�hler number and premixedness parameter and drops to zero on both sides in this parametric space. � 2012 The Combustion Institute.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:05Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:47:23Z : No. of bitstreams: 1 2-s2.0-80054916182.pdf: 415307 bytes, checksum: f1de55c13d0c9537402066a956d60fb5 (MD5) Made available in DSpace on 2014-05-27T11:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-10-15 The location of invariant tori for a two-dimensional Hamiltonian mapping exhibiting mixed phase space is discussed. The phase space of the mapping shows a large chaotic sea surrounding periodic islands and limited by a set of invariant tori. Given the mapping considered is parameterised by an exponent γ in one of the dynamical variables, a connection with the standard mapping near a transition from local to global chaos is used to estimate the position of the invariant tori limiting the size of the chaotic sea for different values of the parameter γ. © 2011 Elsevier B.V. All rights reserved. Departamento de Estatística Matemat. Apl. e ComputaoInstituto de Geociências e Ciências Exatas UNESP Univ Estadual Paulista, Av.24A, 1515Bela Vista, CEP: 13506-900 Rio Claro SP Departamento de Estatística Matemat. Apl. e ComputaoInstituto de Geociências e Ciências Exatas UNESP Univ Estadual Paulista, Av.24A, 1515Bela Vista, CEP: 13506-900 Rio Claro SP

We introduce a general framework which allows to verify if abstract wave equations with generalized Wentzell boundary conditions are well-posed, i.e., are governed by a cosine family. As an example we study wave equations for second order differential operators on C[0,1] with non-local Wentzell-type boundary conditions. Moreover, in Appendix A we give a perturbation result for sine and cosine families.

Los resultados financieros de las organizaciones son objeto de estudio y análisis permanente, predecir sus comportamientos es una tarea permanente de empresarios, inversionistas, analistas y académicos. En el presente trabajo se explora el impacto del tamaño de los activos (valor total de los activos) en la cuenta de resultados operativos y netos, analizando inicialmente la relación entre dichas variables con indicadores tradicionales del análisis financiero como es el caso de la rentabilidad operativa y neta y con elementos de estadística descriptiva que permiten calificar los datos utilizados como lineales o no lineales. Descubriendo posteriormente que los resultados financieros de las empresas vigiladas por la Superintendencia de Sociedades para el año 2012, tienen un comportamiento no lineal, de esta manera se procede a analizar la relación de los activos y los resultados con la utilización de espacios de fase y análisis de recurrencia, herramientas útiles para sistemas caóticos y complejos. Para el desarrollo de la investigación y la revisión de la relación entre las variables de activos y resultados financieros se tomó como fuente de información los reportes financieros del cierre del año 2012 de la Superintendencia de Sociedades (Superintendencia de Sociedades, 2012). The financial results of organizations are studied and ongoing analysis, predicting their behaviors is an ongoing task of entrepreneurs, investors, analysts and academics. In this paper the impact of the size of the assets in the income statement is scanned, initially analyzing the relationship between these variables with traditional indicators of financial analysis such as the operating and net profitability, with elements of descriptive statistics and statistical models to describe the data used as linear or nonlinear. Discovering later that the financial results of the companies have a nonlinear behavior is to analyze the relationship of assets and results with the use of phase spaces and recurrence analysis, useful tools for chaotic and complex systems. For the development of research and review of the relationship between the variables of financial assets and results was taken as source of information financial reporting year-end 2012 of Superintendencia de Sociedades (Superintendencia de Sociedades, 2012). CENTRO DE ESTUDIOS EMPRESARIALES PARA LA PERDURABILIDAD

We show how to explicitly determine the space-frequency window (phase-space window) for optical systems consisting of an arbitrary sequence of lenses and apertures separated by arbitrary lengths of free space. If the space-frequency support of a signal lies completely within this window, the signal passes without information loss. When it does not, the parts that lie within the window pass and the parts that lie outside of the window are blocked, a result that is valid to a good degree of approximation for many systems of practical interest. Also, the maximum number of degrees of freedom that can pass through the system is given by the area of its space-frequency window. These intuitive results provide insight and guidance into the behavior and design of systems involving multiple apertures and can help minimize information loss.

Classical sum rules arise in a wide variety of physical contexts. Asymptotic expressions have been derived for many of these sum rules in the limit of long orbital period (or large action). Although sum rule convergence may well be exponentially rapid for chaotic systems in a global sense with time, individual contributions to the sums may fluctuate with a width which diverges in time. Our interest is in the global convergence of sum rules as well as their local fluctuations. It turns out that a simple version of a lazy baker map gives an ideal system in which classical sum rules, their corrections, and their fluctuations can be worked out analytically. This is worked out in detail for the Hannay-Ozorio sum rule. In this particular case the rate of convergence of the sum rule is found to be governed by the Pollicott-Ruelle resonances, and both local and global boundaries for which the sum rule may converge are given. In addition, the width of the fluctuations is considered and worked out analytically, and it is shown to have an interesting dependence on the location of the region over which the sum rule is applied. It is also found that as the region of application is decreased in size the fluctuations grow. This suggests a way of controlling the length scale of the fluctuations by considering a time dependent phase space volume, which for the lazy baker map decreases exponentially rapidly with time., Comment: 15 pages, 2 figures, submitted to Phys. Rev. E

Çetin, Serkant Ali (Dogus Author) -- Yıldız, Süleyman Cenk (Dogus Author) -- Conference full title: 2010 IEEE Nuclear Science Symposium conference record (NSS/MIC 2010) : [including the 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference, and the 17th International Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (RTSD)]; Knoxville, Tennessee, USA, 30 October - 6 November 2010 The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, 4He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing 3He phase the studied mass range is now being extended further. In this contribution the final results of CAST's 4He phase will be presented and the current status of the 3He run will be given. This includes latest results as well as prospects of future axion experiments. Nucl. Plasma Sci. Soc. Inst. Electr. Electron. Eng. (NPSS)

Linear canonical transforms (LCTs) form a three-parameter family of integral transforms with wide application in optics. We show that LCT domains correspond to scaled fractional Fourier domains and thus to scaled oblique axes in the space-frequency plane. This allows LCT domains to be labeled and ordered by the corresponding fractional order parameter and provides insight into the evolution of light through an optical system modeled by LCTs. If a set of signals is highly confined to finite intervals in two arbitrary LCT domains, the space-frequency (phase space) support is a parallelogram. The number of degrees of freedom of this set of signals is given by the area of this parallelogram, which is equal to the bicanonical width product but usually smaller than the conventional space-bandwidth product. The bicanonical width product, which is a generalization of the space-bandwidth product, can provide a tighter measure of the actual number of degrees of freedom, and allows us to represent and process signals with fewer samples.

We study the transport properties of passive inertial particles in a $2-d$ incompressible flows. Here the particle dynamics is represented by the $4-d$ dissipative embedding map of $2-d$ area-preserving standard map which models the incompressible flow. The system is a model for impurity dynamics in a fluid and is characterized by two parameters, the inertia parameter $\alpha$, and the dissipation parameter $\gamma$. We obtain the statistical characterisers of transport for this system in these dynamical regimes. These are, the recurrence time statistics, the diffusion constant, and the distribution of jump lengths. The recurrence time distribution shows a power law tail in the dynamical regimes where there is preferential concentration of particles in sticky regions of the phase space, and an exponential decay in mixing regimes. The diffusion constant shows behaviour of three types - normal, subdiffusive and superdiffusive, depending on the parameter regimes. Phase diagrams of the system are constructed to differentiate different types of diffusion behaviour, as well as the behaviour of the absolute drift. We correlate the dynamical regimes seen for the system at different parameter values with the transport properties observed at these regimes, and in the behaviour of the transients. This system also shows the existence of a crisis and unstable dimension variability at certain parameter values. The signature of the unstable dimension variability is seen in the statistical characterisers of transport. We discuss the implications of our results for realistic systems., Comment: 28 pages, 14 figures, To Appear in Phys. Rev. E; Vol. 79 (2009)

Cataloged from PDF version of article. Affine canonical transforms, complex-order Fourier transforms, and their associated coherent states appear in two scenarios: finite-discrete and continuum. We examine the relationship between the two scenarios, making systematic use of inductive limits, which were developed in the preceding articles in this series. © 2003 American Institute of Physics.

Phase spaces are different ways to represent signals. Owing to their properties, they are often used for signal compression and recognition with high discrimination abilities. We present several recently introduced Wigner-related sets of representations that have improved signal processing performance, and we introduce an optical implementation. This study deals with the generalized Wigner spaces, the fractional Fourier transform, and the x-p and the r-p representations. The optical implementations are demonstrated and discussed. © 2000 Optical Society of America.

In this paper, we use existence families and admissible phase spaces to study the Cauchy problem for a class of nonlinear abstract functional differential equations with infinite delay in a unified way. Our main results concern the existence and uniqueness of mild solutions, strong solutions, and classical solutions.

Recent numerical studies suggest that in pipe and related shear flows, the region of phase space separating laminar from turbulent motion is organized by a chaotic attractor, called an edge state, which mediates the transition process. We here confirm the existence of the edge state in laboratory experiments. We observe that it governs the dynamics during the decay of turbulence underlining its potential relevance for turbulence control. In addition we unveil two unstable traveling wave solutions underlying the experimental flow fields. This observation corroborates earlier suggestions that unstable solutions organize turbulence and its stability border.