Smart Wireless Power Transfer Operated by Time-Modulated Arrays via a Two-Step Procedure

The paper introduces a novel method for agile and precise wireless power transmission operated by a time-modulated array. The unique, almost real-time reconfiguration capability of these arrays is fully exploited by a two-step procedure: first, a two-element time-modulated subarray is used for localization of tagged sensors to be energized; the entire 16-element TMA then provides the power to the detected tags, by exploiting the fundamental and first-sideband harmonic radiation. An investigation on the best array architecture is carried out, showing the importance of the adopted nonlinear/full-wave computer-aided-design platform. Very promising simulated energy transfer performance of the entire nonlinear radiating system is demonstrated

A theoretical and numerical approach for selecting miniaturized antenna topologies on magneto-dielectric substrates

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies

Co-Design Strategies for Energy-Efficient UWB and UHF Wireless Systems

This paper reviews the most recent methods, combining nonlinear harmonic-balance-based analysis with electromagnetic (EM) simulation, for optimizing, at the circuit level, modern radiative RF/microwave systems. In order to maximize the system efficiency, each subsystem must be designed layoutwise, accounting for the presence of the others, that is, accounting for its actual terminations, rather than the ideal ones (50 Ω). In this way, the twofold goal of minimizing size and losses of the system is obtained by reducing intersystem matching networks. Indeed, terminations are complex, frequency-dispersive, and variable with the signal level, if active operations are concerned, and are responsible for performance degradation if not properly optimized. This approach is nowadays necessary, given the ever increased spread of pervasively distributed RF microsystems adopting miniaturized antennas, such as radio frequency identification (RFID) or wireless sensor networks, that must be low-cost, low-profile, low-power, and must simultaneously perform localization, identification, and sensing. For the design of a transmitter and a receiver connected with the respective antennas, suitable figures of merit are considered, encompassing radiation and nonlinear performance. Recent representative low-profile realizations, adopting ultra-wideband (UWB) excitations are used to highlight the benefit of the proposed nonlinear/EM approach for next generation energy autonomous microsystem, such as UWB-RFID tags

RF Systems Design for Simultaneous Wireless Information and Power Transfer (SWIPT) in Automation and Transportation

This work presents some recent solutions that exploit the wireless power transfer (WPT) technology for energizing moving vehicles and machinery tools. Such technology is currently experiencing unprecedented interests in non-traditional RF/microwave sectors fields, such the industrial automation and the railway transportation safety. Near-field electromagnetic coupling solutions are presented showing that, in order to obtain efficient performances for broad ranges of operating conditions, the nonlinear electromagnetic co-design of the entire WPT system, from the energy source to the receiver load, needs to be carried out. This technology can be combined with wireless data transfer, thus realizing integrated systems able to simultaneously control the energy transfer and the transmission of data. The adopted operating frequencies are in the MHz range, which is only recently considered for this kind of applications. In particular this work focuses on three different systems: the first one demonstrates the constant powering of “on the move” industrial charts at 6.78 MHz, regardless of the relative position of the transmitter and the receiver sub-systems; the second one presents a novel design of a balise transportation system adopting a high efficiency GaN-based transmitter designed to keep its performance over a wide range of loading conditions; the last one consists of the simultaneous wireless power and data transfer, to a rotating machinery tool, automatically controlled by the powering system based on the coexistence of frequency-diverse inductive and capacitive couplings

Infraestructura Obsoleta: reutilización de los silos subterráneos de Rosario

El presente trabajo propone la reutilización de la edificación obsoleta como mecanismo que posibilita, por un lado, repensar soluciones alternativas a las modalidades de crecimiento que impulsan las ciudades, y por otro, señalar un compromiso con la construcción histórica y colectiva de la ciudad. En correspondencia con la historia y territorio particular de la región donde se opera, se selecciona —dentro de la infraestructura del modelo agroexportador— los silos subterráneos de la ciudad de Rosario como caso específico de estudio e intervención. A partir de la interpretación de las preexistencias y de la riqueza espacial y simbólica que estas estructuras poseen, se estudian posibilidades de intervención, se reconocen alternativas al derribo y se formulan estrategias para su reactivación mediante nuevos usos

Microstructural damage evaluation of ferritic-ausferritic spheroidal graphite cast iron

The goal of this work is to improve the understanding of the relation between the microstructural characteristics of Intercritical Austempered Ductile Cast Iron (IADI) and the damage micromechanisms observed during its tensile loading. The experimental methodology involves heat treatments to obtain IADI and the assessment of the damage mechanisms (sequence and occurrence) during step by step tensile testing. The damage evaluation was carried out by observing the surface of the tensile test specimen with optical and scanning electron microscopy. The results show that small cracks start forming soon after the yield stress is surpassed. The crack initiation is preferentially located at matrix-nodule interface. As loading increases, cracks also develop at the ferritic grain boundaries and the ausferritic/ferritic interfaces. Consequently, at higher strain values, a competition between the plastic deformation on internodular zones and crack propagation along ausferritic phase is observed. Finally, the final fracture is produced by the propagation of cracks across the internodular ligaments and through the ausferritic/ferritic interface that later coalesce into a single dominant crack leading to the material failure

Vigilancia epidemiológica de la calidad de los servicios de salud bucal del primer nivel de atención

El objetivo del siguiente trabajo es evaluar la implementa- ción de un Sistema de Vigilancia Epidemiológico en Salud Bucal, que permita medir la calidad de la atención de los prestadores de salud del Primer Nivel. Para ello se medirá la atención según estándares de calidad en sus componentes de estructura, procesos y resultados, analizando la posible asociación del grado de cumplimiento de los diferentes tipos de estándares, entre las distintas dimensiones de la variable o áreas de evaluación. Luego se diseñará un plan de mejora continua de la calidad, el cual una vez desarrollado se medirá y comparará luego de la implementación de acciones de mejora.Facultad de Odontologí

Segunda etapa del plan de mejora continua de la calidad en salud bucal en la ciudad de Berisso, provincia de Buenos Aires

La calidad de la atención debe considerarse como uno de los factores determinantes de la salud y el bienestar general de la sociedad. Marc Lalonde agrega a los ya conocidos determinantes de la salud (estilo de vida, factores biológicos, entre otros), a los sistemas y servicios de salud, como un factor más que incide sobre el estado de salud de la comunidad. Este concepto justifica la existencia de un programa de mejora continua de la calidad en la medida que éste contribuye a conservar la salud general de la comunidad, desde el nivel local, en que se cumplan los objetivos y actividades que garanticen la salud. De acuerdo al plan de trabajo realizado con el objetivo de evaluar los resultados de la implementación de un "Programa de Mejora Continua de la Calidad", a través de la evolución en el nivel de calidad de atención odontológica de los prestadores de salud del Primer Nivel de Atención, es que se evaluaron seis efectores de primer nivel de atención -CAPS- del municipio de Berisso a través de un diseño de intervención en tres etapas. De la etapa diagnóstica, es que se realizaron planes estratégicos presentados.Facultad de Ciencias Médica