1,938 research outputs found
Alternative conducted immunity tests
Conducted immunity tests are always performed by the use of CDNs in laboratories in accordance with the standard EN61000-4-6. However, it is not always possible to use CDNs because of some limitations. If the EUT (Equipment Under Test) has large dimensions or high currents, it is not, most of the time, possible to send it to an EMC laboratory or to use CDNs during the test. As a consequence, usage of BCI probes is inevitable in industry. In this paper, we compared the laboratory setup installed with CDNs and alternative setups installed directly on mains without any CDNs in terms of loop impedances and injected loop currents. We also established a link based on the loop impedances and the injected currents on the test loops between the two setups. Finally, a first serious step was taken to establish the fundamentals of alternative conducted immunity tests based on the impedance measurements of test loops for industry.Postprint (published version
Design of a controller for wheeled mobile robots based on automatic movement sequencing
There are many kinds of robots and among them the wheeled mobile robots (WMR) stand out, because they are relatively cheap and easy to build. These features make WMRs the test prototypes for control strategies or motion generation. In general, the controllers developed are based on sensory schemes that give an WMR the ability to travel through flat or obstructed environments. However, these strategies are highly reactive, i.e. they are based on the control-action scheme and are not adaptive; or, they are motion schemes built from simulations that assume the environmental conditions to determine the robot's path. In both cases, WMRs do not adapt perfectly to the change of environment, since the controller does not find appropriate movements for the robot to move from one point to another. Therefore, this article proposesapartial solution to this problem, with a controller that generates sets of adaptive movements for an WMR to travel around its environment from the sensory perception information
Low cost, high performance fuel cell energy conditioning system controlled by neural network
Fuel cells are an important option for the generation of renewable, efficient and environmentally friendly electricity. Although there are commercial applications in the industrial, residential and automotive sectors, it is not yet a mature technology and requires much research, particularly to reduce its costs to a level competitive with other technologies. This research is currently focused not only on the structure of the cell but also on the additional elements and sub systems required for its implementation as an energy solution. In this article, we propose an electrical energy conditioning scheme for the Formic acid fuel cell (direct formic acid fuel cellor DFAFC). This fuel cell was selected for its high performance, and low cost in low and medium power applications. The proposed system consists of a direct current-direct current (DC-DC) regulator supported by a power converter controlled by a Cortex-M3 ARM processor. This CPU is used to propagate a static neural network trained with the non-linear dynamics of the power converter. The power circuit is modeled and simulated to produce the training parameters. The neural network is trained externally and runs off-line on the processor. The results show not only the regulation capacity of the control scheme but also its response speed to sudden changes in the load
A gain-scheduled LPV control for oxygen stoichiometry regulation in PEM fuel cell systems
The article addresses the LPV control of a Polymer Electrolyte Membrane Fuel Cell (PEMFC). In order to optimize efficiency, PEMFCs require reliable control systems ensuring stability and performance, as well as robustness to model uncertainties
and external perturbations. On the other hand, PEMFCs present a highly nonlinear behavior that demands nonlinear and/or adaptive control strategies to achieve high performance in the entire operating range. Here, a linear parameter varying (LPV) gain scheduled control is proposed. The control is based on a piecewise affine LPV representation of the PEMFC, a model that can be available in practice. In order to deal with the saturation of the control action, an LPV anti-windup compensation is also proposed. The complete control strategy is applied to several experimental practical situations in a laboratory fuel cell system to evaluate its performance and the reliability of the proposed algorithms.The research of F.D. Bianchi was supported by the European Regional Development Funds (ERDF, FEDER Programa Competitivitat de Catalunya 2007-2013). The research of C. Kunusch has been supported by the Seventh Framework Programme of the European Community through the Marie Curie actions (GA: PCIG09-GA-2011-293876) and project Puma-Mind (GA: FCH-JU-2011-1-303419), as well as by the CICYT project DPI2011-25649 (MICINN-Spain). The research of C. Ocampo-Martinez has been supported by the project MACPERCON (Ref. 201250E027) of the CSIC. The research of R.S. Sánchez Peña has been supported by CONICET and
grant PICT2008-290 from the PRH Program of the Ministry of Science, Technology and Innovation of Argentina.Peer Reviewe
Modification of characters linked to Cucurbita maxima domestication. Using morphometry as a tool for identification
El objetivo de este trabajo consiste en reconocer patrones de variación morfométrica –mediante la aplicación de análisis multivariado para tamaño y forma- en semillas de C. maxima que sean diagnósticos para formas domesticadas, silvestres e híbridas actuales, a fin de aplicarlos a la identificación de semillas arqueológicas. Para lograr este objetivo se midieron con calibre digital 1317 semillas de las formas antedichas y de nueve sitios arqueológicos de Argentina y Perú. Se exploró el patrón de variación entre las mismas en tamaño y forma mediante análisis multivariado. Se identificó una tendencia general hacia la disminución de la variabilidad en forma y tamaño a lo largo del tiempo, con una primera etapa donde se mantuvieron ejemplares híbridos, generándose nuevas formas y una segunda donde se mantuvieron los rasgos de momentos previos y el aumento del tamaño de las semillas
A compact dosimetric system for MOSFETs based on passive NFC tag and smartphone
The authors acknowledge the Servicio de Radiofísica (Radio-physics Service) of the Hospital Universitario San Cecilio (Granada, Spain) for permitting us to use their installations. This work was funded by the Spanish Government under project FPA2015-67694-P (Spanish Ministry of Economy, Industry and Competitiveness) and a R&D predoctoral grant (FPU13/05032, Spanish Ministry of Education, Culture and Sport). This project is partially supported by European Regional Development Funds (ERDF).In this work we describe and evaluate a dosimetric system based on an NFC (Near Field Communication) tag and a smartphone that uses commercial MOSFETs as radiation sensors. The tag is designed with commercial integrated circuits and the smartphone is the power source of the tag configured as a readout unit, user interface and storage unit. The NFC tag is supplied wirelessly by the smartphone via NFC, using a home-made structure to align the tag coil and smartphone coil in order to achieve a good inductive coupling. In this case, the commercial DMOS transistor ZVP3306 is used as dosimeter in unbiased mode, connected to the tag before and after each irradiation session to perform the sensor reading. An evaluation of the dosimetric system has been carried out irradiating three transistors with photon beam of 6 MV up to 20 Gy. The average sensitivity found is (4.75 ± 0.15) mV/Gy, which is in good agreement with the results found with our previously developed dosimetric system. Therefore, this miniaturised dosimetric system can be considered as a promising and low cost electronic architecture to be used for dosimetry control in radio-therapy treatments.Servicio de Radiofísica (Radio-physics Service) of the Hospital Universitario San Cecilio (Granada, Spain)Spanish Government under project FPA2015-67694-P (Spanish Ministry of Economy, Industry and Competitiveness) and a R&D predoctoral grant (FPU13/05032, Spanish Ministry of Education, Culture and Sport)European Regional Development Funds (ERDF
Diseño e implementación del compilador STL para el PLC-UD
En este artículo se describe el proceso de diseño e implementación del compilador STL para el PLC-UD, el cual está encargado de generar código ejecutable para los PLC, a partir del lenguaje estructurado STL. El trabajo consta de dos partes fundamentales, la gestión del hardware y el proceso de compilación. Para la primera parte se definen las rutinas en lenguaje máquina necesarias en la compilación, y para la segunda parte se muestran las técnicas de compìlación utilizadas y la forma como se implantó el compilador, utilizando el lenguaje C++
Sistema de encendido de combustible usando celdas Peltier
The objective is to design a power supply system for an electric arc ignition circuit, in a conventional domestic stove, that uses Peltier cells as electric generation source. The regular working conditions of a domestic gas stove were replicated, doing temperature measurements by means of a thermographic camera on the stove surfaces, and by means of a conventional instrument on its inner room. Starting from the measurements, the most appropriate type of Peltier cell was selected, as well as its amount and optimum location. After that, the prototype circuit was design, as for the load of the storage device, as for the electric arc ignition system. A design of a battery-based power supply circuit was obtained, whose energy recharge source is based on Peltier cells, and which has an energy consumption of 650mW. In conclusion, It is possible to use the thermal energy produced by a stove or any other energy dissipating, for supplying power to low-power circuits, taking advantage of the thermoelectric effect.El objetivo es diseñar un sistema de alimentación para un circuito de ignición por arco eléctrico, para una estufa domestica convencional, que utilice celdas Peltier como fuente de generación de energía eléctrica. Se replicaron las condiciones normales de funcionamiento de una estufa a gas doméstica, realizando mediciones de temperatura con una cámara termográfica sobre las superficies de la estufa, y con un medidor convencional sobre su espacio interno. Partiendo de las mediciones realizadas, se seleccionó el tipo de celda Peltier más adecuado, así como también su cantidad y posición óptima. Posteriormente, se procedió a realizar un diseño del circuito prototipo tanto para la carga del dispositivo de almacenamiento como para el sistema de ignición por arco eléctrico. Se obtuvo el diseño de un circuito de alimentación basado en una batería, cuya fuente de recarga de energía está basada en celdas Peltier, teniendo un consumo estimado de 650mW. En conclusión, es posible utilizar la energía térmica producida por una estufa o cualquier otro elemento disipador de energía en forma de calor para alimentar circuitos de baja potencia, aprovechando el efecto termoeléctrico
Systematic review of pragmatic randomised control trials assessing the effectiveness of professional pharmacy services in community pharmacies
Background: Implementation of Professional Pharmacy Services (PPSs) requires a demonstration of the service’s
impact (efficacy) and its effectiveness. Several systematic reviews and randomised controlled trials (RCT) have shown
the efficacy of PPSs in patient’s outcomes in community pharmacy. There is, however, a need to determine the
level of evidence on the effectiveness of PPSs in daily practice by means of pragmatic trials.
To identify and analyse pragmatic RCTs that measure the effectiveness of PPSs in clinical, economic and humanistic
outcomes in the community pharmacy setting.
Methods: A systematic search was undertaken in MEDLINE, EMBASE, the Cochrane Library and SCIELO. The search
was performed on January 31, 2020. Papers were assessed against the following inclusion criteria (1) The
intervention could be defined as a PPS; (2) Undertaken in a community pharmacy setting; (3) Was an original paper;
(4) Reported quantitative measures of at least one health outcome indicator (ECHO model); (5) The design was
considered as a pragmatic RCT, that is, it fulfilled 3 predefined attributes. External validity was analyzed with PRECIS-
2 tool.
Results: The search strategy retrieved 1,587 papers. A total of 12 pragmatic RCTs assessing 5 different types of PPSs
were included. Nine out of the 12 papers showed positive statistically significant differences in one or more of the
primary outcomes (clinical, economic or humanistic) that could be associated with the following PPS: Smoking
cessation, Dispensing/Adherence service, Independent prescribing and MTM. No paper reported on costeffectiveness
outcomes.
Conclusions: There is limited available evidence on the effectiveness of community-based PPS. Pragmatic RCTs to
evaluate clinical, humanistic and economic outcomes of PPS are needed
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