RESUMEN
Monitoring of the moisture and temperature of composting process is a key factor to obtain a quality product beyond the quality of raw materials. Current methodologies for monitoring these two parameters are time consuming for workers, sometimes not sufficiently reliable to help decision-making and thus are ignored in some cases. This article describes an advance on monitoring of composting process through a Wireless Sensor Network (WSN) that allows measurement of temperature and moisture in real time in multiple points of the composting material, the Compo-ball system. To implement such measurement capabilities on-line, a WSN composed of multiple sensor nodes was designed and implemented to provide the staff with an efficient monitoring composting management tool. After framing the problem, the objectives and characteristics of the WSN are briefly discussed and a short description of the hardware and software of the network's components are presented. Presentation and discussion of practical issues and results obtained with the WSN during a demonstration stage that took place in several composting sites concludes the paper.
Asunto(s)
Suelo/química , Administración de Residuos , Tecnología Inalámbrica , Temperatura , Agua/análisisRESUMEN
The purpose of this paper is to analyze the influence of the metallic structures of a realistic car body frame on the specific absorption rate (SAR) produced by a cell phone when a complete human body model is placed at different locations inside the vehicle, and to identify the relevant parameters responsible for these changes. The modeling and analysis of the whole system was conducted by means of computer simulations based on the full wave finite-difference time-domain (FDTD) numerical method. The excitation considered was an 835 MHz lambda/2 dipole located as a hands-free communication device or as a hand-held portable system. We compared the SAR at different planes on the human model, placed inside the vehicle with respect to the free space situation. The presence of the car body frame significantly changes the SAR distributions, especially when the dipole is far from the body. Although the results are not conclusive on this point, this change in SAR distribution is not likely to produce an increase above the limits in current guidelines for partial body exposure, but may be significant for whole-body exposure. The most relevant change found was the change in the impedance of the dipole, affecting the radiated power. A complementary result from the electromagnetic computations performed is the change in the electromagnetic field distribution inside a vehicle when human bodies are present. The whole vehicle model has been optimized to provide accurate results for sources placed inside the vehicle, while keeping low requirements for computer storage and simulation time.
Asunto(s)
Teléfono Celular/instrumentación , Modelos Biológicos , Vehículos a Motor , Recuento Corporal Total/métodos , Absorción , Simulación por Computador , Impedancia Eléctrica , Campos Electromagnéticos , Estudios de Factibilidad , Análisis de Elementos Finitos , Humanos , Microondas/efectos adversos , Dosis de Radiación , Reproducibilidad de los Resultados , Irradiación Corporal TotalRESUMEN
We analyze the radiated emissions from a low power electrosurgical unit (ESU). Measurements at a 3-meter distance are performed in order to find a suitable measurement setup intended to reproduce realistically the real working ESU behavior in a test lab. The broad-band and narrow-band characteristics of the perturbation are studied in order to address the other equipment immunity.
Asunto(s)
Campos Electromagnéticos , Electrocirugia/instrumentación , Análisis de Falla de Equipo/métodos , Seguridad de Equipos , Quirófanos , Radiometría/métodos , Falla de Equipo , Dosis de RadiaciónRESUMEN
La entrada en vigor de la nueva edición de la norma EN 60601-1-2:2001 plantea cambios importantes en los ensayos de compatibilidad electromagnética de los equipos electromédicos y también desde el punto de vista de las responsabilidades en los problemas de EMC, aumentando el nivel de implicación de los hospitales (AU)
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