ABSTRACT
There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant's components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid.
ABSTRACT
Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed.
ABSTRACT
Se ha realizado un estudio descriptivo basado en el análisis de las historias clínicas de los trabajadores del hospital que consultaron por dolor de espalda entre enero de 2002 y diciembre de 2008. Ha consultado el 28,3% de los trabajadores. El 31,8% de ellos fueron auxiliares sanitarios; el 24,7%, DUE, y el 21,2%, administrativos. La media de edad fue de 44,6 años. La mayoría de la patología que se diagnosticó fue del tipo artrosis y/o discopatía. Se identificaron periodos de IT en el 28,2% de los trabajadores que consultaron, y al 50% de estos trabajadores se les diagnosticó patología, concentrándose la mayor parte en la columna lumbar (83,3%). La duración de los días de baja estuvo entre 27,7 y 91,7 días (IC 95%). El tratamiento de mayor prescripción fue el médico y rehabilitador. Además de confirmar la relación entre patología y edad, evidenciamos la importancia clínica del dolor de espalda en los trabajadores de nuestro hospital (AU)
We performed a descriptive study based on review of medical records of hospital workers who consulted for back pain between January/2002 and December/2008. It was found that 28.3% of hospital workers consulted for back pain. They were nursing assistants (31.8%), nurses (24.7%), administrative (21.2%) and other. The mean age was 44.6 years old. Most of the pathology diagnosis was by osteoarthritis and/or discopathy. Among the workers who have consulted, 28.3% had some period of temporary work incapacity. 50% of these workers had pathology, located mostly in the lumbar spine (83.3%). The duration of days of incapacity ranged from 27.7 to 91.7 days. The most prescribed treatment was medical and rehabilitation. Besides confirming the relationship between pathology of spine and age, we show the clinical importance of back pain among workers in our hospital (AU)
