Optimización de un algoritmo para la estimación de indicadores de calidad en el medio hídrico y la aplicación al sistema de medidas y comunicaciones asociado

Esta tesis doctoral comprende las investigaciones llevadas a cabo para el diseño de un prototipo de sistema de medida in situ de concentración de nitratos en agua. El sistema propuesto está basado en el análisis mediante técnicas espectrofotométricas de la respuesta espectral en el ultravioleta y su posterior tratamiento mediante técnicas de programación evolutiva. La aplicación principal del sistema diseñado se encuentra en el seguimiento y control de la contaminación del agua por nitratos. En esta tesis, se analiza la respuesta espectral de la concentración de nitrato y nitrito en agua y se caracteriza la variación de la absorción máxima y de la longitud de onda para la cual se produce. Otro aspecto que se aborda es el modelado de dicha respuesta mediante funciones matemáticas. Igualmente, se expone la aplicación de la programación evolutiva como método para determinar la concentración tanto de nitrato, como de otros contaminantes cuya respuesta sea sensible en el rango de longitudes de onda de la instrumentación disponible. Por último, para resolver el problema de la medida in situ de la concentración de nitrato y nitrito se ha realizado un prototipo en colaboración con el Centro de Investigaciones de la Armada (CIDA

Optimización de un algoritmo para la estimación de indicadores de calidad en el medio hídrico y la aplicación al sistema de medidas y comunicaciones asociado

Esta tesis doctoral comprende las investigaciones llevadas a cabo para el diseño de un prototipo de sistema de medida in situ de concentración de nitratos en agua. El sistema propuesto está basado en el análisis mediante técnicas espectrofotométricas de la respuesta espectral en el ultravioleta y su posterior tratamiento mediante técnicas de programación evolutiva. La aplicación principal del sistema diseñado se encuentra en el seguimiento y control de la contaminación del agua por nitratos. En esta tesis, se analiza la respuesta espectral de la concentración de nitrato y nitrito en agua y se caracteriza la variación de la absorción máxima y de la longitud de onda para la cual se produce. Otro aspecto que se aborda es el modelado de dicha respuesta mediante funciones matemáticas. Igualmente, se expone la aplicación de la programación evolutiva como método para determinar la concentración tanto de nitrato, como de otros contaminantes cuya respuesta sea sensible en el rango de longitudes de onda de la instrumentación disponible. Por último, para resolver el problema de la medida in situ de la concentración de nitrato y nitrito se ha realizado un prototipo en colaboración con el Centro de Investigaciones de la Armada (CIDA

Miniaturized high gain flexible spiral antenna tested in human-like tissue

A miniaturized helical antenna is presented in this work. The antenna is flexible, it is 6100 μm long and it has a diameter of 352 μm. This antenna has such a small cross-section, that permits to be implanted in the human body with fine syringes and minimally invasive surgeries. The antenna can be used to receive power and/or send information in medical devices. The antenna is made of biocompatible materials: polytetrafluoroethylene (PFTE) and copper. The fundamental parameters of the antenna have been simulated and experimentally measured in animal human-like tissues, showing good agreement. The resonant frequency of the antenna is 4.7 GHz, with a reflection coefficient of −25.1 dB, and a gain of −4.7 dBi. As expected, the resonant frequency decreases inside biological tissues comparing to the free-space open-air measurement. Reducing the resonant frequency is an advantage because power signals can penetrate deeper into body tissues

Analysis of the geometric parameters influence in PCB fixtures for 2D multipole magnetization patterning of thin layer micro-magnets

Magnetic actuators, magnetic gears, vibrational energy harvesters and other micro-electromagnetic devices requires micro-magnetic rotors with alternant magnetizations to optimize their performance. Different approaches have been used for multipole magnetization of micro-magnets like fixed micro-fixtures, thermomagnetic patterning or laser machining. The main limitation of the previous techniques is that the inversion of the magnetic polarizations is only partially done. In this work, a concept based on 2D multipole magnetization printing of micro-magnets is proposed and analyzed to overcome current limitations. The fixtures are designed to be printed on a standard 35 μm PCB. The dependence of the magnetizing field with respect to the geometrical parameter of the fixture is analyzed. Maps of the required current for the magnetizing fields are also given. Some design recommendations to optimize the magnetizing field and to minimize current, thus the heat, are given.Universidad de Alcal

Optimal design of electromagnetic field exposure maps in large areas

The mapping of electromagnetic field (EMF) exposure over large areas is a very useful tool for the analysis of epidemiological data and risk assessment. Its production requires a costly measurement process. To optimize the effort and ensure the representativeness of the exposure map, criteria for the selection of the sites to be measured must be established. This paper presents a methodology for conducting EMF exposure maps suitable for risk assessment evaluation in large areas. The proposal combines radio wave propagation criteria and GIS methods to optimize the sampling effort. The design criteria are based on the determination of a rectangular grid of 250 m side and the identification of the emitters within the area under study. Both urban and rural sites are analysed in the proposal and line of sight conditions (LOS) are considered to reduce the number of points required and thus optimize the measurement effort. Depending on the extent and regularity of the surface, the density of measurement points has been estimated to be between 8 and 10 points per square kilometre in the urban area. The proposed methodology has been applied to a case study of a 2.8 km2 urban area within a 35.11 km2 municipality, obtaining an average point density of 9.64 points/km2 in the urban area. The differences in exposure depending on the application of the criteria have been analysed by means of the statistical values of the sets and the subtraction of the maps generated using kriging techniques. According to our results, if LOS measurements are not properly incorporated, the mean value of the EMF is underestimated in the area under study

Model-based systems engineering applied to trade-off analysis of wireless power transfer technologies for implanted biomedical microdevices

Decision-making is an important part of human life and particularly in any engineering process related to a complex product. New sensors and actuators based on MEMS technologies are increasingly complex and quickly evolving into products. New biomedical implanted devices may benefit from system engineering approaches, previously reserved to very large projects, and it is expected that this need will increase in the future. Here, we propose the application of Model Based Systems Engineering (MBSE) to systematize and optimize the trade-off analysis process. The criteria, their utility functions and the weighting factors are applied in a systematic way for the selection of the best alternative. Combining trade-off with MBSE allow us to identify the more suitable technology to be implemented to transfer energy to an implanted biomedical micro device.European Commissio

Smartphone-based methodology applied to electromagnetic field exposure assessment

This study presents the measurements of exposure to electromagnetic fields, carried out comparatively following standard methods from fixed sites using a broadband meter and using a smartphone on which an App designed for this purpose has been installed. The results of two measurement campaigns carried out on the campus of the University of Alcalá over an area of 1.9 km2 are presented. To characterize the exposure, 20 fixed points were measured in the first case and 860 points along the route made with a bicycle in the last case. The results obtained indicate that there is proportionality between the two methods, making it possible to use the smartphone for comparative measurements. The presented methodology makes it possible to characterize the exposure in the area under study in four times less time than that required with the traditional methodology.Comunidad de Madri

Modelado eficiente de obstáculos en guía de onda rectangular para simuladores comerciales utilizando código Verilog-A

This paper reports the modelling of classical obstacles (post, iris, screw, etc.) within rectangular waveguide in terms of electrical lumped elements equivalent circuit using Verilog-A language code. This ability, allows making possible the enabling of the digital computer interaction and simulation using standard CAD simulation tools. Furthermore, the paper shows the simplicity and friendly technique of modelling passive microwave devices using Verilog-A code. Several examples have been studied under different commercial simulators: Agilent ADS and GENESYS. A comparison between the results obtained from Verilog-A based simulations and full 3-D electromagnetic simulation is shown, too

Aplicación de la simulación electromagnética en el estudio de filtros paso banda en microstrip

In this paper we present the study of electromagnetic simulation as an educational tool for microwave filters. We have started from the classic coupled lines filter, simulated both by traditional and electromagnetic methods. This way, we can obtain the frequency response and also the electric field distribution. Later, we have introduced ladder line and SIR structures into the classic filter to show the variations in the filter behaviour. These structures have been used to reduce filter size. Finally, we have combined both techniques in the same device. Several filters have been constructed and measured to validate the results obtained by simulation. The proposed designs let us verify concepts such as field distribution, phase velocity and resonator shape influence

Simulación eficiente de filtros en guía de onda mediante Verilog-A

In this paper we present a comparison between universal Verilog-A modeling language and full 3D electromagnetic simulators used for waveguide microwave filter design. Computational time is drastically reduced when Verilog- A language is used for designing compared to full 3D electromagnetic simulations (99.78% reduction compared to FDTD simulator and 99.92% reduction compared to Finite Element Method simulator). Verilog-A modeling language was chosen to describe the electrical behavior of the waveguide obstacle due to the advantages of its portability among different commercial simulation platforms. In this paper, simulated and measured results for a band pass filter of 0.45 GHz bandwidth at 12.62 GHz center frequency, with fifth order Chebyshev response is proposed. The filter has been manufactured on WR- 75 rectangular waveguide and consists of five double post sections. S21 response is reproduced within a 0.7% of the experimental values of the center frequency