A family of Chebyshev-Halley type methods in Banach spaces

A family of third-order iterative processes (that includes Chebyshev and Halley's methods) is studied in Banach spaces. Results on convergence and uniqueness of solution are given, as well as error estimates. This study allows us to compare the most famous third-order iterative processes

Reliability analysis of fracture in piezoelectric components with a random microstructure

The pronounced piezoelectric effect on small length scales is a driving force for the miniaturisation of electromechanical components. With the decrease of component sizes, controllability of production processes becomes increasingly difficult. As a consequence the reliability of these components is significantly influenced by microscopic imperfections. In this contribution, microscopic imperfections in lead zirconate titanate (PZT) are studied. Numerical homogenisation is used to derive random fields for bulk and elastic properties of the piezoelectric material. Stochastic finite element simulations are performed to gain insight in the reliability of a prototypical micro component

A P-Lingua Programming Environment for Membrane Computing

A new programming language for membrane computing, PLingua, is developed in this paper. This language is not designed for a speci c simulator software. On the contrary, its purpose is to o er a general syntactic framework that could de ne a uni ed standard for membrane computing, covering a broad variety of models. At the present stage, P-Lingua can only handle P systems with active membranes, although the authors intend to extend it to other models in the near future. P-Lingua allows to write programs in a friendly way, as its syntax is very close to standard scienti c notation, and parameterized expressions can be used as shorthand for sets of rules. There is a built-in compiler that parses these human-style programs and generates XML documents that can be given as input to simulation tools, di erent plugins can be designed to produce speci c adequate outputs for existing simulators. Furthermore, we present in this paper an integrated development environment that plays the role of interface where P-lingua programs can be written and compiled. We also present a simulator for the class of recognizer P systems with active membranes, and we illustrate it by following the writing, compiling and simulating processes with a family of P systems solving the SAT problem.Ministerio de Educación y Ciencia TIN2006-13425Junta de Andalucía TIC-58

A construction procedure of iterative methods with cubical convergence II: Another convergence approach

We extend the analysis of convergence of the iterations considered in Ezquerro et al. [Appl. Math. Comput. 85 (1997) 181] for solving nonlinear operator equations in Banach spaces. We establish a different Kantorovich-type convergence theorem for this family and give some error estimates in terms of a real parameter [-5, 1). © 1998 Elsevier Science Inc. All rights reserved

A note on a modification of Moser's method

We use a recurrence technique to obtain semilocal convergence results for Ulm's iterative method to approximate a solution of a nonlinear equation F (x) = 0fenced((x n + 1 = x n - B n F (x n),, n 0,; B n + 1 = 2 B n - B n F (x n + 1) B n,, n 0 .))This method does not contain inverse operators in its expression and we prove it converges with the Newton rate. We also use this method to approximate a solution of integral equations of Fredholm-type. © 2007 Elsevier Inc. All rights reserved

An update on the genera Longidorus , Paralongidorus and Xiphinema (Family Longidoridae) in Portugal

The tribe Longidorini within the subfamily Longidorinae (Longidorus spp. and Paralongidorus spp.) and the subfamily Xiphineminae (Xiphinema spp.) are two large nematode groups with about 260 and 230 known species, respectively. They are globally two important groups of ectoparasitic nematodes considered to be major pests because of their activity as vectors of important plant nepovirus, with some species included in the list of quarantine pathogenic organisms in many European countries. Knowledge of the biodiversity and occurrence of this nematode group is a prerequisite for the establishment of sound management strategies and control measures. According to data collected from the databases (such as EPPO, FSTA, and Web of Science) and published in specialised literature, a total of 15 Longidorus, 1 Paralongidorus and 40 Xiphinema species have been recorded as present in Portugal. However, the taxonomic status of some species is controversial, and thus needs to be clarified. A comprehensive review for unravelling the biodiversity and occurrence of nematode species of the genus Longidorus, Paralongidorus and Xiphinema in Portugal is herein provided. This review includes an updated checklist of species with information on the localities, host plants and geographical distribution. Additionally, maps on the species distributions of Longidorinae and Xiphineminae nematodes present in Continental Portugal and the Portuguese Macaronesian islands are provided, as well as unpublished data on authors and comments on the current taxonomic status. Finally, new insights and directions for future research on Longidoridae in Portugal are presented

On the approximation of turbulent fluid flows by the Navier-Stokes-α equations on bounded domains

The Navier-Stokes- equations belong to the family of LES (Large Eddy Simulation) models whose fundamental idea is to capture the influence of the small scales on the large ones without computing all the whole range present in the flow. The constant is a regime flow parameter that has the dimension of the smallest scale being resolvable by the model. Hence, when = 0, one recovers the classical Navier-Stokes equations for a flow of viscous, incompressible, Newtonian fluids. Furthermore, the Navier-Stokes- equations can also be interpreted as a regularization of the Navier- Stokes equations, where stands for the regularization parameter. In this paper we first present the Navier-Stokes- equations on bounded domains with no-slip boundary conditions by means of the Leray regularization using the Helmholtz operator. Then we study the problem of relating the behavior of the Galerkin approximations for the Navier-Stokes- equations to that of the solutions of the Navier-Stokes equations on bounded domains with no-slip boundary conditions. The Galerkin method is undertaken by using the eigenfunctions associated with the Stokes operator. We will derive local- and global-in-time error estimates measured in terms of the regime parameter and the eigenvalues. In particular, in order to obtain global-in-time error estimates, we will work with the concept of stability for solutions of the Navier-Stokes equations in terms of the L2 norm.Ministerio de Educación y Ciencia JC2011-041

Effect of Oak Chip Addition at Different Winemaking Stages on Phenolic Composition of Moravia Agria Red Wines

This study compared changes in the phenolic composition of Moravia Agria wine and its effect on colour,co-pigmentation as well as on physicochemical properties, such as antioxidant capacity, caused by addingoak chips at different stages of the winemaking process. Moravia Agria control wine was made followingtraditional winemaking processes, without oak chips. Oak chips were added to the rest of the wines attwo dose rates (3 and 6 g/L) at different stages of the winemaking process: for one week during alcoholicfermentation, during malolactic fermentation and in young red Moravia Agria wine. Only slight significantdifferences were found in phenolic composition, antioxidant activity and chromatic characteristics betweenthe Moravia Agria wines treated with oak chips and the control wine. However, oak chip addition slightlydecreased the content of non-polymeric red pigments (monomeric anthocyanins and pyranoanthocyanins)and also of resveratrol-monomer stilbenes. It is suggested that oak chip addition to Moravia Agria winescan be selected as part of the targeted sensory profile (relative intensity of sensory descriptors providedby grape and oak wood), since only a few changes have been observed in the phenolic profiles, antioxidantcapacity value and colour characteristics

Bounds on the dipole moments of the tau-neutrino via the process e+e−→ννˉγe^{+}e^{-}\rightarrow \nu \bar \nu \gamma in a 331 model

We obtain limits on the anomalous magnetic and electric dipole moments of the $\nu_{\tau}$ through the reaction $e^{+}e^{-}\rightarrow \nu \bar \nu \gamma$ and in the framework of a 331 model. We consider initial-state radiation, and neglect $W$ and photon exchange diagrams. The results are based on the data reported by the L3 Collaboration at LEP, and compare favorably with the limits obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C. arXiv admin note: substantial text overlap with arXiv:hep-ph/060527

Impact of climate change on solar irradiation and variability over the Iberian Peninsula using regional climate models

As solar energy will be an increasingly important renewable energy source in the future years, the study of how climate change affects both temporal and spatial variability is very important. In this paper, we study future changes of the solar radiation resource in the Iberian Peninsula (IP) through a set of simulations from ESCENA project until mid-century. The evaluation of the simulations against observations indicates contrasting biases for the different regional climate models (RCMs) in terms of solar irradiation amount and its interannual variability. We propose a diagnostic for the quality of solar energy resource, in which the gridpoints are classified in four categories depending on the combination of solar irradiation amount and variability. The observed large percentage of points in the optimal category (high irradiation/low variability) in the IP is captured by the RCMs in general terms. The analysis of scenarios indicates a future increase in solar irradiation, although not all scenarios agree in the geographical distribution of this increase. In most projections, a shift is projected from the category with optimal resource quality towards the category with high irradiation/high variability, pointing to a certain quality loss in the solar resource. This result is not general, as a few scenarios show an opposite result. The exceptions are not linked to a particular GCM or emissions scenario. Finally, results from a first approximation to the issue of the ability of solar energy to cover power demand peaks in summer show important differences between regions of the IP. The spatially-averaged correlation of solar irradiation and summer surface temperatures for the whole IP is rather high, which is a positive result as the strong interconnections of the power grid within the IP could allow a distribution of solar power surpluses in certain regions for such high-temperature episodes