IDTPI - Artículos de revistas

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Now showing 1 - 9 of 9
  • Publication
    Non-contact linear slider for cryogenic environment
    (Elsevier, 2012-03-01) Pérez Díaz, José Luis; García Prada, Juan Carlos; Díez Jiménez, Efrén; Valiente Blanco, Ignacio; Berit, Sander; Lauri, Timm; Sanchez Garcia-Casarrubios, Juan; Serrano, Javier; Romera, Fernando; Argelaguet-Vilaseca, Heribert; Gonzalez-De-Maria, David
    A non-contact linear slider based on stable superconducting magnetic levitation with a long permanent magnet as a slider and two fixed superconducting disks which define the slide way has been designed, built and tested. The slider can be moved stably along a stroke of ± 11.5 mm by supplying a low current in a coil located at the end of the stroke while the levitation remains stable providing a reliable mechanism for linear displacement in a cryogenic environment. The response is linear with a sensitivity of 52 ± 2 mum/mA for displacements lower than 6 mm. Run out, pitch, yaw and roll have been measured demonstrating an overall good performance. In all cases the measured hysteresis was lower than 250 mum and the measured run out was also lower than 250 mum both for Y and Z axis. Roll and yaw were always below 300 murad, that is one order of magnitude lower than the pitch (4500 murad).
  • Publication
    Stable thrust on a finite-sized magnet above a Meissner superconducting torus
    (AIP Publishing, 2013-02-14) Pérez Díaz, José Luis; Díez Jiménez, Efrén; Valiente Blanco, Ignacio; Herrero-De-Vicente, J.
    Forces and torques exerted by a superconducting torus on a permanent magnet have been mapped. It is demonstrated that stable orbits exist. Moreover, provided that the magnet remains in any of these orbits, the first critical field in the superconductor is never overpassed and the superconductor remains in the Meissner state. The consequent absence of hysteresis makes these kinds of device perfect candidates for non-frictional bearings or gyroscopes.
  • Publication
    Superconducting noncontact device for precision positioning in cryogenic environments
    (IEEE, 2014-04-01) Pérez Díaz, José Luis; Valiente Blanco, Ignacio; Díez Jiménez, Efrén; Sanchez Garcia-Casarrubios, Juan
    In this paper, a noncontact linear positioner based on superconducting magnetic levitation for high-precision positioning has been tested under cryogenic conditions (similar to 20 K and similar to 10(-6) Pa). The prototype is able to achieve submicrometric positioning resolution of 230 +/- 30 nm RMS along a stroke of +/- 9 mm length with a current resolution of 15 mu A, and a peak current requirement lower than +/- 500 mA. In addition, it was demonstrated that an open-loop control strategy could be used for positioning the moving part with the accuracy of the order of 1 mu m. On the other hand, deviations of the slider position were found to be +/- 650 mu rad for the pitch, lower than 100 mu rad for the yaw, +/- 2000 mu rad for the roll, and +/- 4 mu m for the lateral run, all of them related to a full stroke motion. These results reveal a good performance of the device and demonstrate the potential of a new tool for applications, where high-precision positioning is required within a long range in cryogenic environments like far-infrared interferometry.
  • Publication
    Fogs: Physical Basis, Characteristic Properties, and Impacts on the Environment and Human Health
    (MDPI, 2017-10-20) Perez Diaz, Jose L.; Ivanov, Ognyan; Peshev, Zahary; Alvarez Valenzuela, Marco A.; Valiente Blanco, Ignacio; Evgenieva, Tsvetina; Dreischuh, Tanja; Gueorguiev, Orlin; Todorov, Peter V.; Vaseashta, Ashok; European Commission
    This work presents a selective overview of natural fogs in terms of fog types, forms and states of occurrence, physical, micro-physical, chemical and dynamic properties, basic characterizing parameters, etc. In focus are related achievements and contributions reported mainly during the last decade and a half, as a result of both laboratory studies and field observations. Processes of homogeneous and heterogeneous nucleation are analyzed in the aspects of condensation, nuclei diversity and specifics, as related to the activation, growth and deposition of fog droplets. The effect is highlighted of the water vapor's partial pressure on the surface tension of the liquid water-air interface and the freezing point of the water droplets. Some problems and aspects of fog modeling, parameterization, and forecasting are outlined and discussed on the examples of newly developed relevant 1D/3D theoretical models. Important issues of fog impacts on the air quality, ecosystems, water basins, societal life, and human health are also addressed and discussed, particularly in cases of anthropogenically modified (chemical, radioactive, etc.) fogs. In view of reducing the possible negative effects of fogs, conclusions are drawn concerning the new demands and challenges to fog characterization imposed by the changing natural and social environment and the needs for new data on and approaches to more adequate observations of fog-related events.
  • Publication
    Evaluation of user response by using visual cues designed to direct the viewer's attention to the main scene in an immersive environment
    (Springer, 2023-01) Ortega-Alvarez, Galo; Matheus-Chacin, Carlos; García Crespo, Ángel; Ruiz-Arroyo, Adrian
    Today the visualization of 360-degree videos has become a means to live immersive experiences.. However, an important challenge to overcome is how to guide the viewers attention to the video main scene, without interrupting the immersion experience and the narrative thread. To meet this challenge, we have developed a software prototype to assess three approaches: Arrows, Radar and Auto Focus. These are based on visual guidance cues used in first person shooter games such as: Radar-Sonar, Radar-Compass and Arrows. In the study a questionnaire was made to evaluate the comprehension of the narrative, the user's perspective with respect to the design of the visual cues and the usability of the system. In addition, data was collected on the movement of the user's head, in order to analyze the focus of attention. The study used statistical methods to perform the analysis, the results show that the participants who used some visual cue (any of these) showed significant improvements compared to the control group (without using visual cues) in finding the main scene. With respect to narrative compression, significant improvements were obtained in the user group that used Radar and Auto Focus compared to the control group.
  • Publication
    Fast surface disinfection with COUNTERFOG® SDR-F05A+
    (Springer, 2021-04-12) Pérez Díaz, José Luis; Sánchez García-Casarrubios, Juan; Méndez-Vigo Carranza, Pablo; Ruiz Navas, Elisa María; Iliev Petrov, Mihayl; Alcami Pertejo, Antonio; Vázquez, Ángela; Rastrojo, Alberto; Archilla, Víctor; Sánchez García, María; Fernández Perea, Gonzalo
    COUNTERFOG® has been proposed as a rapid decontamination and disinfection technology that uses dynamic submicrometric-disinfecting fog cones. When projected onto surfaces, they create a micrometre-thick film of disinfectant minimizing the use of liquids and the impact on environment. The extremely thin film is intended to be enough to cover and kill microorganisms and simultaneously thin enough to evaporate in a few minutes¿depending on the environmental conditions. In the present work, experimental tests were carried out to verify this hypothesis. These include a physical characterization of the fog in the cone, a measurement of the liquid flow projected on surfaces as well as disinfection tests with a series of microorganisms. In addition to these results, operational recommendations are derived to ensure disinfection reliability.
  • Publication
    Decontamination of Diesel particles from air by using the Counterfog (R) system
    (Springer Science and Business Media LLC, 2019-03) Pérez Díaz, José Luis; Llerena Aguilar, F. J.; Martin Perez, T.; Sánchez García-Casarrubios, Juan; Ruiz Navas, Elisa María
    The existence of particles with diameter under 10m in air is strongly correlated with respiratory diseases. These particles are profusely produced by heating systems, traffic, and Diesel engines creating a serious problem to modern cities. Natural mechanisms removing particles from the atmosphere are too slow to deal with the huge amount of particles daily released by human activity. The objective of this work is to measure the effectiveness of a new technology called Counterfog (R) to eliminate airborne particles. The results show that Counterfog (R) is able to wash out PM10, PM5, and PM2.5 Diesel-generated airborne particles quite efficiently.
  • Publication
    Development of an anomaly alert system triggered by unusual behaviors at home
    (MDPI, 2021-08-02) Rodriguez Goncalves, Roxana; García Crespo, Ángel; Matheus Chacin, Carlos; Ruiz Arroyo, Adrián; European Commission
    In many countries, the number of elderly people has grown due to the increase in the life expectancy of the population, many of whom currently live alone and are prone to having accidents that they cannot report, especially if they are immobilized. For this reason, we have developed a non-intrusive IoT device, which, through multiple integrated sensors, collects information on habitual user behavior patterns and uses it to generate unusual behavior rules. These rules are used by our SecurHome system to send alert messages to the dependent person's family members or caregivers if their behavior changes abruptly over the course of their daily life. This document describes in detail the design and development of the SecurHome system.
  • Publication
    Design and analysis of a non-hysteretic passive magnetic linear bearing for cryogenic environments
    (2014-10) Díez Jiménez, Efrén; Valiente Blanco, Ignacio; Castro Fernández, Victor; Pérez Díaz, José Luis
    In this study, the mechanical design and analysis of a magnetic levitating linear bearing suitable for working in the nonhysteretic range of forces is presented. The semi-cylindrical design of the superconductor provides stable equilibrium positioning and restoring forces in all degrees of freedom except for two with a cylindrical magnet floating along the axis of revolution/displacement. Using finite element analysis, it has been proven that the magnet can float stably and passively in a complete non-hysteretic Meissner state. This non-hysteretic passive linear bearing could be suitable for long-stroke precision positioning. The high translational symmetry of the magnetic field seen by the superconductor assures a usable long stroke of around 90mm with full performance and 150mm with reduced performance. This linear bearing in combination with an actuating system for only one degree of freedom could be used for accurate precision positioning systems for cryogenic environments with zero hysteresis in the movement.