Variable order Mittag-Leffler fractional operators on isolated time scales and application to the calculus of variations

We introduce new fractional operators of variable order on isolated time scales with Mittag-Leffler kernels. This allows a general formulation of a class of fractional variational problems involving variable-order difference operators. Main results give fractional integration by parts formulas and necessary optimality conditions of Euler-Lagrange type.Comment: This is a preprint of a paper whose final and definite form is with Springe

A hybrid numerical scheme for fractional-order systems

In this work we present a hybrid numerical scheme for the solution of systems of fractional differential equations arising in several fields of engineering. The numerical scheme can deal with both smooth and non-smooth solutions, and, the idea behind the hybrid method is that of approximating the solution as a linear combination of non-polynomial functions in a region near the singularity, and by polynomials in the remaining domain. The numerical method is then used to study fractional RC electrical circuits.The first, third and fourth authors would like to thankthe funding by FCT-Portuguese Foundation for Science and Technology throughscholarship and projects: SFRH/BPD/100353/2014 and UID/Multi/04621/2013, UID/MAT/00297/2013 (Centro de Matem ́atica e Aplica ̧c ̃oes), respectively

Coating of Felt Fibers with Carbon Nanotubes and PEDOT with Different Counterions: Temperature and Electrical Field Effects.

The use of wearable devices has promoted new ways of integrating these devices, one of which is through the development of smart textiles. Smart textiles must possess the mechanical and electrical properties necessary for their functionality. This study explores the impact of polymer-felt microstructure variations on their morphology, electrical, and mechanical properties. The application of thermal treatment, along with an electric field, leads to a substantial structural reorganization of the molecular chains within pristine felt. This results in a system of nanofibrils coated with MWCNT-PEDOT, characterized by highly ordered counterions that facilitate the flow of charge carriers. Both temperature and an electric field induce reversible microstructural changes in pristine felt and irreversible changes in coated felt samples. Furthermore, electropolymerization of PEDOT significantly enhances electrical conductivity, with PEDOT:BTFMSI-coated fabric exhibiting the highest conductivity

Sensitive CO and 13CO survey of water fountain stars Detections towards IRAS 18460-0151 and IRAS 18596+0315

 This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this recordContext. Water fountain stars represent a stage between the asymptotic giant branch (AGB) and planetary nebulae phases, when the mass loss changes from spherical to bipolar. These types of evolved objects are characterized by high-velocity jets in the 22 GHz water maser emission. Aims. The objective of this work is to detect and study in detail the circumstellar gas in which the bipolar outflows are emerging. The detection and study of thermal lines may help in understanding the nature and physics of the envelopes in which the jets are developing. Methods. We surveyed the CO and 13CO line emission towards a sample of ten water fountain stars through observing the J = 1 → 0 and 2 → 1 lines of CO and 13CO, using the 30 m IRAM radio-telescope at Pico Veleta. All the water fountains visible from the observatory were surveyed. Results. Most of the line emission arises from foreground or background Galactic clouds, and we had to thoroughly analyse the spectra to unveil the velocity components related to the stars. In two sources, IRAS 18460-0151 and IRAS 18596+0315, we identified wide velocity components with a width of 35 - 40 km s-1 that are centred at the stellar velocities. These wide components can be associated with the former AGB envelope of the progenitor star. A third case, IRAS 18286-0959, is reported as tentative; in this case a pair of narrow velocity components, symmetrically located with respect to the stellar velocity, have been discovered. We also modelled the line emission using an LVG code and derived some global physical parameters, which allowed us to discuss the possible origin of this gas in relation to the known bipolar outflows. For IRAS 18460-0151 and IRAS 18596+0315, we derived molecular masses close to 0.2 M⊙, mean densities of 104 cm-3, and mass-loss rates of 10 -4 M⊙ yr-1. The kinetic temperatures are rather low, between 10 and 50 K in both cases, which suggests that the CO emission is arising from the outer and cooler regions of the envelopes. No fitting was possible for IRAS 18286-0959, because line contamination can not be discarded in this case. Conclusions. The molecular masses, mean densities, and mass-loss rates estimated for the circumstellar material associated with IRAS 18460-0151 and IRAS 18596+0315 confirm that these sources are at the end of the AGB or the beginning of the post-AGB evolutionary stages. The computed mass-loss rates are among the highest ones possible according to current evolutionary models, which leads us to propose that the progenitors of these water fountains had masses in the range from 4 to 8 M ⊙. We speculate that CO emission is detected in water fountains as a result of a CO abundance enhancement caused by current episodes of low-collimation mass-loss. © ESO, 2013.MICINNJunta de Andalucí

Expressiveness of Temporal Query Languages: On the Modelling of Intervals, Interval Relationships and States

Storing and retrieving time-related information are important, or even critical, tasks on many areas of Computer Science (CS) and in particular for Artificial Intelligence (AI). The expressive power of temporal databases/query languages has been studied from different perspectives, but the kind of temporal information they are able to store and retrieve is not always conveniently addressed. Here we assess a number of temporal query languages with respect to the modelling of time intervals, interval relationships and states, which can be thought of as the building blocks to represent and reason about a large and important class of historic information. To survey the facilities and issues which are particular to certain temporal query languages not only gives an idea about how useful they can be in particular contexts, but also gives an interesting insight in how these issues are, in many cases, ultimately inherent to the database paradigm. While in the area of AI declarative languages are usually the preferred choice, other areas of CS heavily rely on the extended relational paradigm. This paper, then, will be concerned with the representation of historic information in two well known temporal query languages: it Templog in the context of temporal deductive databases, and it TSQL2 in the context of temporal relational databases. We hope the results highlighted here will increase cross-fertilisation between different communities. This article can be related to recent publications drawing the attention towards the different approaches followed by the Databases and AI communities when using time-related concepts

A disk of dust and molecular gas around a high-mass protostar

The processes leading to the birth of low-mass stars such as our Sun have been well studied, but the formation of high-mass (> 8 x Sun's mass) stars has heretofore remained poorly understood. Recent observational studies suggest that high-mass stars may form in essentially the same way as low-mass stars, namely via an accretion process, instead of via merging of several low-mass (< 8 Msun) stars. However, there is as yet no conclusive evidence. Here, we report the discovery of a flattened disk-like structure observed at submillimeter wavelengths, centered on a massive 15 Msun protostar in the Cepheus-A region. The disk, with a radius of about 330 astronomical units (AU) and a mass of 1 to 8 Msun, is detected in dust continuum as well as in molecular line emission. Its perpendicular orientation to, and spatial coincidence with the central embedded powerful bipolar radio jet, provides the best evidence yet that massive stars form via disk accretion in direct analogy to the formation of low-mass stars

Stellar Coronal and Wind Models: Impact on Exoplanets

Surface magnetism is believed to be the main driver of coronal heating and stellar wind acceleration. Coronae are believed to be formed by plasma confined in closed magnetic coronal loops of the stars, with winds mainly originating in open magnetic field line regions. In this Chapter, we review some basic properties of stellar coronae and winds and present some existing models. In the last part of this Chapter, we discuss the effects of coronal winds on exoplanets.Comment: Chapter published in the "Handbook of Exoplanets", Editors in Chief: Juan Antonio Belmonte and Hans Deeg, Section Editor: Nuccio Lanza. Springer Reference Work

EVOLUCIÓN DE LOS PARTOS MÚLTIPLES EN LA REGIÓN DE MURCIA DESDE 1.996 HASTA 2.008: IMPLICACIONES PSICOSOCIALES

Multiple delivery carries a series of psychosocial implications which concern both the parents and the social and health care systems. The possibility of complications increases in multiple pregnancies, as well as the needs for attention and care for both, the babies and the parents. Therefore, information about the evolution of this kind of pregnancies is very important to identify people’s health needs. Objectives: The main objective of this research is to show the evolution of multiple deliveries in Spain, and in the Murcia Region between 1996 and 2008. Additional objectives are to examine those data according to mother’s age at maternity, and to analyze possible consequences of such evolution. Method: Information has been obtained from the National Institute of Statistics and the Murcia Regional Centre of Statistics databases. Results: Multiple births rate has changed form 13.1‰ in 1996 to 18.4‰ in 2008 in Murcia (12.7‰ to 19.4‰ in Spain). The biggest increase has taken place in mothers older than 30 years old. Conclusion: This situation presents important implications for the families and for the health system as a whole. Families need to reach an adaptation and health workers might collaborate giving adequate information and orientation.Los partos múltiples conllevan una serie de implicaciones psicosociales que afectan tanto a los padres como a los sistemas de atención sanitaria y social. La posibilidad de que se produzcan complicaciones se incrementa en el caso de un embarazo múltiple, así como las necesidades de atención y cuidados tanto para los bebés como para los padres. Disponer de información acerca de la evolución de este tipo de embarazos resulta, por tanto, de gran relevancia para identificar necesidades de salud en la población. Objetivos: Este trabajo tiene como principales objetivos presentar la evolución de los partos múltiples entre los años 1996 y 2008, tanto en la Región de Murcia como en España, examinar estos datos en función de la edad de la madre en el momento del nacimiento y analizar las posibles repercusiones de esta evolución. Método: Para ello se ha utilizado la información disponible en las bases de datos del Instituto Nacional de Estadística y del Centro Regional de Estadística de Murcia. Resultados: En los últimos años se ha producido un importante aumento en el número de partos múltiples tanto a nivel nacional como en las distintas comunidades autónomas, la Región de Murcia entre ellas. La tasa de partos gemelares o de orden mayor ha pasado a ser de 13.1‰ en 1996 a 18.4‰ en 2008 en Murcia (12.7‰ a 19.4‰ en España). El mayor incremento se ha producido en los grupos de madres a partir de los 30 años. Conclusiones: Esta situación presenta implicaciones importantes para el sistema de salud en su conjunto y para las familias. Éstas necesitan conseguir una adaptación en la que puede colaborar de forma decisiva el profesional sanitario proporcionando una información y orientación adecuada