Waveguide Model for Thick Complementary Split Ring Resonators

This paper presents a very simple analytical model for the design of Frequency Selective Surfaces based on Complementary Split Ring Resonators (CSRR) within the microwave range. Simple expressions are provided for the most important geometrical parameters of the model, yielding an accurate description of the CSRR resonance frequency and avoiding full-wave numerical simulations. Besides, a qualitative description of the band-pass filter behavior of these structures is described, considering its high quality factor Q.Comment: Paper accepted at the 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting. paper submission #286

Analysis of a Waveguide-Fed Metasurface Antenna

The metasurface concept has emerged as an advantageous reconfigurable antenna architecture for beam forming and wavefront shaping, with applications that include satellite and terrestrial communications, radar, imaging, and wireless power transfer. The metasurface antenna consists of an array of metamaterial elements distributed over an electrically large structure, each subwavelength in dimension and with subwavelength separation between elements. In the antenna configuration we consider here, the metasurface is excited by the fields from an attached waveguide. Each metamaterial element can be modeled as a polarizable dipole that couples the waveguide mode to radiation modes. Distinct from the phased array and electronically scanned antenna (ESA) architectures, a dynamic metasurface antenna does not require active phase shifters and amplifiers, but rather achieves reconfigurability by shifting the resonance frequency of each individual metamaterial element. Here we derive the basic properties of a one-dimensional waveguide-fed metasurface antenna in the approximation that the metamaterial elements do not perturb the waveguide mode and are non-interacting. We derive analytical approximations for the array factors of the 1D antenna, including the effective polarizabilities needed for amplitude-only, phase-only, and binary constraints. Using full-wave numerical simulations, we confirm the analysis, modeling waveguides with slots or complementary metamaterial elements patterned into one of the surfaces.Comment: Original manuscript as submitted to Physical Review Applied (2017). 14 pages, 14 figure

Pact of silence: cultural perspectives of disclosure to terminal patient

Trabajo fin de grado en EnfermeríaObjetivo: Evaluar la posible influencia que ejerce la cultura en relación a la presencia del pacto de silencio del paciente terminal en la sociedad actual. Material y métodos: se ha realizado una revisión narrativa mediante la búsqueda bibliográfica en bases de datos de Ciencias de la Salud (Cochrane Plus, PubMed, Cinahl, SCielo, PsycINFO y EBSCO Host), revistas científicas y sedes webs institucionales. Los artículos seleccionados responden a los siguientes criterios de inclusión: pacientes adultos, artículos publicados a partir del año 2000, en inglés, francés o español, a texto completo libre, referentes a enfermedad terminal respondiendo a la pregunta de investigación. Resultados: fueros incluidos 35 artículos clasificando los resultados en torno a tres categorías: perspectiva del paciente, perspectiva de la familia y perspectiva de los profesionales de la salud. Discusión/ Conclusiones: La actitud del paciente favorable a recibir información, difiere completamente de la opinión de la familia y los profesionales, éstos se oponen a ella por diversos motivos (protección al familiar enfermo, escasa formación en la comunicación…). Por otro lado, este deseo de conocer es independiente de la influencia social establecida.Objective: To evaluate the possible influence of culture in relation to the presence of the pact of silence of terminally ill patients in today’s society. Methods: a narrative review has been done through bibliographic research in Health Science databases (Cochrane Plus, PubMed, Cinahl, SCielo, PsycINFO and EBSCO Host), scientific magazines and institutional websites. The articles selected answer the following inclusion criteria: adult patients, articles published since 2000, in English, French or Spanish, Free Full Text, concerning terminal illness, answering the research question. Results: 35 articles were included and the results classified into three categories: patient´s perspective, family´s perspective and health professional’s perspective. Discussion/ Conclusions: The favorable attitude of the patient to receive information is completely different from the views of the family and professionals; they oppose it for several reasons (sick relative´s protection, poor communication training ...). On the other hand, this desire to know is independent of the established social influence