A set of rapid-response models for pollutant dispersion assessments in southern Spain coastal waters

Three rapid-response Lagrangian particle-tracking dispersion models have been developed for southern Spain coastal waters. The three domains cover the Gulf of Cádiz (Atlantic Ocean), the Alborán Sea (Med iterranean), and the Strait of Gibraltar with higher spatial resolution. The models are based on different hydrodynamic submodels, which are run in advance. Tides are calculated using a 2D barotropic model in the three cases. Models used to obtain the residual circulation depend on the physical oceanography of each region. Thus, two-layer models are applied to Gibraltar Strait and Alborán Sea and a 3D baroclinic model is used in the Gulf of Cádiz. Results from these models have been compared with observations to validate them and are then used by the particle-tracking models to calculate dispersion. Chemical, radioactive and oil spills may be simulated, incorporating specific processes for each kind of pollutant. Several application examples are provided

Physically-insightful equivalent circuit models for electromagnetic periodic structures

In this presentation it will be discussed how to obtain analytical or quasi-analytical equivalent circuits to deal with periodic structures such as frequency selective surfaces and/or metasurfaces. Both the topology and the values of the involved elements of these circuits are obtained from a basic rationale to solve the corresponding integral equation. This procedure, besides providing a very efficient analysis/design tool, allows for a good physical insight into the operating mechanisms of the structure in contrast with the almost blind numerical scheme of commercial simulators.Ministerio de Economía y Competitividad TEC2013-41913-PJunta de Andalucía P12-TIC-143

Some advances in the circuit modeling of extraordinary optical transmission

The phenomenon of extraordinary optical transmission (EOT) through electrically small holes perforated on opaque metal screens has been a hot topic in the optics community for more than one decade. This experimentally observed frequency-selective enhanced transmission of electromagnetic power through holes, for which classical Bethe's theory predicts very poor transmission, later attracted the attention of engineers working on microwave engineering or applied electromagnetics. Extraordinary transmission was first linked to the plasma-like behavior of metals at optical frequencies. However, the primary role played by the periodicity of the distribution of holes was soon made evident, in such a way that extraordinary transmission was disconnected from the particular behavior of metals at optical frequencies. Indeed, the same phenomenon has been observed in the microwave and millimeter wave regime, for instance. Nowadays, the most commonly accepted theory explains EOT in terms of the interaction of the impinging plane wave with the surface plasmon-polariton-Bloch waves (SPP-Bloch) supported by the periodically perforated plate. The authors of this paper have recently proposed an alternative model whose details will be briefly summarized here. A parametric study of the predictions of the model and some new potential extensions will be reported to provide additional insight.Ministerio de Ciencia e Innovación TEC2007-65376, CSD2008-0006

On the Computation of the Dispersion Diagram of Symmetric One-Dimensionally Periodic Structures

A critical discussion on the computation of the dispersion diagram of electromagnetic guiding/radiating structures with one-dimensional periodicity using general-purpose electromagnetic simulation software is presented in thiswork. In thesemethods, full-wave simulations of finite sections of the periodic structure are combined with appropriate simplifying network models. In particular, we analyze the advantages and limitations of two different combined methods, with emphasis on the determination of their range of validity. Our discussion is complemented with several selected numerical examples in order to show the most relevant aspects that a potential user of these methods should be aware of. Special attention is paid to the relevant role played by the high-order coupling between adjacent unit cells and between the two halves of unit cells exhibiting reflection, inversion, and glide symmetries.Ministerio de Ciencia, Innovación y Universidades TEC2017-84724-

Circuit model for a periodic array of slits sandwiched between two dielectric slabs

This paper proposes an equivalent circuit model that uses lumped elements and transmission lines to explain the transmission of electromagnetic waves through a conducting screen periodically perforated with slits and sandwiched between two different dielectric slabs. The present model relies on the impedance-matching point of view, previously introduced by some of the authors, rather than on the surface plasmon polariton concept. Thus, the model constitutes a simple and insightful framework that easily leads to accurate qualitative and quantitative predictions about the nature of the transmission spectrum of such structures.Ministerio de Ciencia e Innovación TEC2007-65376, CSD2008-00066Junta de Andalucía TIC-459

Two-dimensional study of leaky modes in microstrip line with a semi-infinite cover layer

This work presents a two-dimensional (2-D) study of the modal spectrum of a single microstrip and a pair of coupled microstrip lines with an upper dielectric half-space. This 2-D study is postulated as the necessary step previous to the 3-D investigation of the potential applications of leaky-wave antennas radiating in an environment susceptible to be modeled by a dielectric half-space. Thus the nature and the possible transitions of the modal spectrum will be characterized for a wide range of values of the permittivity of the upper half-space (∈u). From a physical rationale, the modal spectrum is expected to comprise only leaky modes for values of ∈u greater than the permittivity of the line substrate (∈). This hypothesis is corroborated by the computed numerical results, which, for the case of the microstrip with an air gap, also show that the above assertion is satisfied even for values of ∈u less than ∈. Although the nature of the mathematical transition from bound to leaky modes could not be rigorously established, there has been always found a "physical" transition from each fundamental bound mode (BM) to a space-wave leaky mode (SPWLM). This type of direct physical transition from a fundamental BM to a SPWLM, which is not allowed in a frequency evolution, has been proved to be mathematically viable.Ministerio de Ciencia y Tecnología TIC2001 - 316

Fully analytical circuit-like approach for the TE scattering by narrow-slit printed gratings

A fully analytical solution for the scattering of a uniform TE polarized plane wave by an infinite periodic printed array of narrow slits is provided in this contribution. The model is based on some simplifications made on the formulas arising from a rigorous full-wave formulation. The present approach gives the topology of the transverse equivalent network as well as closed-form expressions for all its components, and overall very accurate results.Ministerio de Ciencia e Innovación TEC2010-16948, CSD2008-00066Junta de Andalucía TIC-459

Influencia de las estrategias de neuromarketing para el posicionamiento de las marcas Coca Cola y Pepsi Co en los consumidores de la ciudad de Estelí en el año 2015

El presente trabajo investigativo tiene como objeto analizar la influencia de las estrategias de neuromarketing en el posicionamiento de las marcas Coca Cola y Pepsi Co en los consumidores de la ciudad de Estelí, ya que hoy en día muchas de las marcas están apostando a que los nuevos avances en las neurociencias, son la solución perfecta para entender el porqué del comportamiento de los consumidores y sus decisiones de compra. El propósito de esta investigación contribuye a comprender mejor las reacciones de los consumidores de bebidas gaseosas en la ciudad de Estelí, además de obtener un mejor conocimiento de los estímulos que condicionan las decisiones en el mercado y una reflexión sobre las causas profundas que afectan al funcionamiento del marketing tradicional utilizado por nuestras marcas y empresas, tanto a nivel local como nacional, y que por el solo hecho de desconocer un sin número de avances científicos en el campo de las neurociencias hoy en día muchas de ellas no ha sido capaces de cumplir con su metas y objetivos planteados. En el marco teórico de esta investigación encontrara información de mucho interés que da un sustento científico a la misma, a partir de diversas teorías y estudios realizados por especialistas en diversas áreas como las neurociencias, marketing, economía, sociología, psicología, medicina humana, entre otras. En la investigación se plantea como hipótesis que las marcas Coca Cola y Pepsi Co han logrado posicionarse en la mente de los consumidores de la ciudad de Estelí, debido a la influencia de las estrategias de neuromarketing que utilizan para generar un mayor impacto emocional; a partir de las variables neuromarketing, consumidores, posicionamiento, marca y publicidad, se diseñaron los instrumentos y métodos para la recolección de la información necesaria, que dan salida a los objetivos formulados en la investigación. En el apartado diseño metodológico, se describen todos los elementos metodológicos que fundamentan el proceso investigativo que se llevó acabo, como son; el enfoque de la investigación, universo, muestra, métodos, técnicas y herramientas utilizadas para la recolección y procesamiento de la información, pero además se encuentran procedimientos realizados en cada uno de los 5 experimentos a los que fueron sometidos personas de diferentes edades y sexos. Se logró obtener resultados relevantes que demuestran que estas marcas han logrado su posicionamiento de manera efectiva en la mente de los consumidores de la ciudad de Estelí; a través de diversas estrategias de neuromarketing que logran generar un mayor impacto emocional, logrando en los consumidores lovemark y engagement; y muchas de estas estrategias pueden ser retomados e implementadas por empresas locales en nuestro país que les permitan cumplir con sus objetivos empresariales, pero además lograr un verdadero nivel de posicionamiento en la mente de sus consumidores

Resonant Modes of a Waveguide Iris Discontinuity: Interpretation in Terms of Canonical Circuits

This paper presents an eigenproblem for computing the resonances of multiresonant irislike discontinuities in waveguides. The formulation of the eigenproblem is based on integral equation methods, and its solution provides the resonance frequencies (eigenvalues) and the associated resonant aperture field's patterns (eigenvectors). These eigenvectors can be used as a basis for the expansion of the aperture fields at any frequency within the band of interest, thus leading to a significant reduction of the size of the method-of-moments admittance matrix. Moreover, under certain approximations, the orthogonality of the eigenvectors allows for the derivation of a Foster-like canonical equivalent circuit with capacitances and inductances that present a smooth frequency dependence. In order to obtain an equivalent Foster circuit with frequency-independent inductors and capacitors, a straightforward and simple iterative refinement is proposed. The circuit thus obtained accurately reproduces the response of the multiresonant irislike discontinuity over a wide frequency band.Ministerio de Economía y Competitividad TEC2013-41913-P, TEC2017-84724-PJunta de Andalucía P12-TIC-143

Enhanced Implementation of the Complex Images Method to Study Bound and Leaky Regimes in Layered Planar Printed Lines

The discrete complex image technique, originally developed to deal with three-dimensional planar structures, has been recently applied to two-dimensional planar and nonplanar transmission lines embedded in layered substrates. In spite of successive refinements, some important practical issues concerning the sampling path, treatment of spectral Green's functions poles, and extension to the leaky regime are still open and deserve deeper examination. It will be shown that a suitable choice of the sampling path is key to reducing the number of images and to avoid the necessity of extracting spectral poles when the bound regime is considered. The situation arising from the analysis of the leaky regime becomes more complex and the adequate choice of the sampling path, as well as an appropriate pole extraction, turn out to be essential. In particular, a new pole-extraction strategy able to deal with poles associated with both proper and improper modes of the background waveguide is proposed. The advantages of using the theory in this paper will be illustrated by diverse numerical results for the bound/leaky regime of various planar lines. Finally, the suitability of the method for covered planar lines will be demonstrated.Ministerio de Ciencia y Tecnología TIC2001-316