Effect of event-based sensing on IoT node power efficiency. Case study: air quality monitoring in smart cities

The predicted growth of urban populations has prompted researchers and administrations to improve services provided to citizens. At the heart of these services are wireless networks of multiple different sensors supported by the Internet of Things. The main purpose of these networks is to provide sufficient information to achieve more intelligent transport, energy supplies, social services, public environments (indoor and outdoor) and security, etc. Two major technological advances would improve such networks in Smart Cities: efficient communication between nodes and a reduction in each node's power consumption. The present paper analyses how event-based sampling techniques can address both challenges. We describe the fundamentals of the triggering mechanisms that characterise Send-on-Delta, Send-on-Area, Send-on-Energy and Send-on-Prediction techniques to restrict the number of transmissions between the sensor node and the supervision or monitoring node without degrading tracking of the sensed variable. At the same time, these aperiodic techniques reduce consumption by sensor node electronic devices. In order to quantify the energy savings, we evaluate the increase achieved in the average lifetime of sensor node batteries. The data provided by Smart City tools in the city of Santander (Spain) were selected to conduct a case study of the main pollutants that determine city air quality: SO2 , NO2 , O3 and PM10 . We conclude that event-based sensing techniques can yield up to 50% savings in sensor node consumption compared to classical periodic sensing techniques

TRIBUNAL ARBITRAL DE ISAGEN S.A. E.S.P. VS. CENTRAL HIDROELECTRICA DE CALDAS S.A. E.S.P.

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Valorization of date palm (Phoenix dactylifera L.) pruning biomass by co-composting with urban and agri-food sludge

In the Mediterranean countries, there is an increasing production of date palm wastes (Phoenix dactylifera L.), not only due to the raising production of date palm fruits, but also derived from the maintenance of urban and peri-urban green areas, especially in those affected by red palm weevil (Rhynchophorus ferrugineus). The management of this increasing volume of green wastes usually concludes with a controlled disposal that implies an important loss of resources, in terms of organic matter, nutrients and energy. In addition, the rise of wastewater generation and the incentive of the wastewater treatment processes have derived in an increase of the amount of the sludge produced, which makes difficult its management. This work studies the feasibility of co-composting palm wastes with sludge from the urban and agri-food sectors as alternative treatment to manage these organic waste streams and to obtain added-value compost. For this, four mixtures (P1, P2, P3 and P4) were prepared using as main component palm leave waste (PL) mixed with different types of sludge. In the piles P1, P2 and P3, sewage sludge (SS) was used as co-composting agent, while agri-food sludge (AS) was used in P4. Throughout composting, the thermal profile of the composting piles was assessed, as were physical, chemical, physico-chemical and maturity parameters. In addition, the changes in water-soluble organic matter were assessed using chemical analytical methods and the excitation–emission matrix (EEM) fluorescence spectroscopy. The results obtained showed the viability of the co-composting process to obtain end-products with adequate maturity degree and physical characteristics for their potential use as substrates, except for the salt contents that can limit their use in some agricultural sectors.This work has been financed by the Spanish Ministry of Economy and Competitiveness and by European Regional Development Funds (ERDF, “Una manera de hacer Europa”), in the framework of the project “Development of new resources and bioproducts based on residues of palmaceous species oriented to carbon sequestration and mitigation strategies, Palmresource” (Project AGL2013-41612-R)

Eficiencia energética de computadores personales: un análisis comparativo

The demand for electricity related to Information and Communication Technologies is constantly growing and contributing significantly to the increase in global greenhouse gas emissions. To reduce this harmful growth, it is necessary to approach the problem from different perspectives. One of them is to implement changes of scale, such as migrating, if possible, algorithms and processes to more energy efficient resources. In this context, this article explores the possibility of running scientific and engineering programs on personal computers and compares the energy efficiency obtained on these devices with that of more powerful computers and even supercomputers. As an anecdote, it shows how the energy efficiency obtained for the same workloads in personal computers is similar to that of some supercomputers included in the Green500 ranking.La demanda de electricidad relacionada con las Tecnologías de la Información y la Comunicación está en constante crecimiento y contribuyendo significativamente al aumento de las emisiones globales de gases de efecto invernadero. Para reducir este crecimiento nocivo, es necesario abordar el problema desde diferentes perspectivas. Una de ellas es implementar cambios de escala, como migrar, si es posible, algoritmos y procesos a recursos energéticamente más eficientes. En este contexto, este artículo explora la posibilidad de ejecutar programas científicos y de ingeniería en computadores personales y compara la eficiencia energética obtenida en estos dispositivos con la de computadores más potentes e incluso supercomputadores. Como anécdota, se muestra cómo la eficiencia energética obtenida para las mismas cargas de trabajo en computadores personales es similar a la de algunos supercomputadores incluidos en el ranking Green500.Investigación financiada parcialmente por el Ministerio de Ciencia, Innovación y Universidades (MICIU) junto con el Fondo Europeo de Desarrollo Regional (FEDER), proyecto PGC2018-098813-B-C31

Advanced monitoring of rail breakage in double-track railway lines by means of PCA techniques

This work describes a classifier designed to identify rail breakages in double-track railway lines, completing the electronic equipment carried out by authors. The main objective of this proposal is to guarantee the integrity of tracks before the railway traffic starts working. In addition, it facilitates maintenance tasks providing information about possible breakages. The detection of breakages is based on the analysis of eight currents provided by the electronic equipment, one per rail, at the ends of the section (emitting and receiving nodes). The imbalance that occurs among the value of these currents implies that there is at least a breakage in the track section under analysis. This analysis is conducted according to three phases. The first one identifies whether there is a breakage, and, in that case, the damaged track is identified. The second phase provides information about which rail is broken (internal, external or both of them) in the previously identified track. Finally, if there is only one breakage, the third phase estimates its most likely zone along the track section. This situation is considered as a classification problem, and solved by means of the Principal Component Analysis technique. This means that a significant number of measurements is required for every breakage pattern (types of breakages) to be considered. Due to the difficulty of having real data, the proposal has been validated using an 8km-long double-track hardware simulator specially designed by the authors, with specific localizations for breakages

Acción tutorial y competencias transversales: alcance de la contribución de los/as tutores/as de Filosofía y Letras, UA

La contribución que nos proponemos presentar atiende dos vertientes de la investigación que hemos llevado a cabo en este curso 2014/2015 en la red en investigación en docencia universitaria dedicada a la Acción tutorial de nuestro centro (Filosofía y Letras, UA). En un primer tiempo, daremos cuenta brevemente del análisis de los resultados obtenidos en las ediciones anteriores. Para ello expondremos cuestiones organizativas que han pretendido conseguir un mayor alcance de la labor de los tutores en colaboración con los tutores par, analizaremos y evaluaremos las medidas de mejora implementadas en el transcurso de las ediciones. En un segundo tiempo, analizaremos y evaluaremos el alcance del equipo de la Acción tutorial en su apoyo a los estudiantes en la adquisición de las competencias transversales. Nuestra investigación tiene como objetivo principal la medición de resultados obtenidos desde la implementación de la figura del tutor par en colaboración con el tutor docente así como la ideación de medidas de optimización para asegurar el espacio necesario para el funcionamiento correcto y pleno de la Acción Tutorial en todas sus dimensiones

Nitrogen fertilization after robusta coffee pruning in Cambisols

The objective of this work was to evaluate the influence of nitrogen mineral fertilization, after robusta coffee pruning, on crop yield and some chemical (pH, organic matter) and microbiological (biological gas exchange and nitrification) soil indicators in two Cambisols in Tercer Frente, Santiago de Cuba, and La Alcarraza, Holguín, during the years 2003–2007. The response to increasing doses of N (0 up to 400 kg ha-1), in the presence of fixed amounts of P (50 kg ha-1) and K (160 kg ha-1), was studied in a randomized block design with four replicates. To obtain coffee yields between 0.50 and 0.84 Mg ha-1, 75 kg ha-1 N are sufficient. In both soils, applications of 100 kg ha-1 N allowed for coffee yields between 1.22 and 1.25 Mg ha-1. With a dose of 153 kg ha-1 N, 1.80 Mg ha-1 coffee yields are obtained, whereas for yields higher than 2 Mg ha-1, it is necessary to apply 200 kg ha-1 N. There was a significant coffee yield increment per each kilogram of N applied, which ranged from 2.13 to 7.80. The proposed doses per site did not affect the microbial activity or soil organic matter. There was a soil pH reduction compared to its initial stage.El objetivo de este trabajo fue evaluar la influencia de la fertilización mineral nitrogenada, después de la poda del cafeto robusta, sobre la productividad del cultivo y algunos indicadores químicos (pH, materia orgánica) y microbiológicos (respiración biológica y nitrificación) de dos Cambisoles en Tercer Frente, Santiago de Cuba y La Alcarraza, Holguín, durante los años 2003–2007. Se estudió la respuesta a dosis crecientes de nitrógeno (0 hasta 400 kg ha-1), en presencia de un fondo fijo de P (50 kg ha-1) y K (160 kg ha-1), en un diseño experimental de bloques al azar, con cuatro réplicas. Para productividades entre 0,50 y 0,84 Mg ha-1 de café, son suficientes 75 kg ha-1 de N. Aplicaciones de 100 kg ha-1 de N permitieron productividades de 1,22 a 1,25 Mg ha-1 de café. Con dosis de 153 kg ha-1 de N, se logran producciones de 1,80 Mg ha-1 de café, mientras que para productividades superiores a 2 Mg ha-1 se necesita aplicar 200 kg ha-1 en ambos suelos. Se encontró un incremento importante en las productividades del cafeto por cada quilogramo de N aplicado, que osciló entre 2,13 y 7,80. Las dosis propuestas por sitio no afectaron la actividad microbiana y la materia orgánica de los suelos. Se encontró disminución del pH del suelo respecto a su estado inicial.The objective of this work was to evaluate the influence of nitrogen mineral fertilization, after robusta coffee pruning, on crop yield and some chemical (pH, organic matter) and microbiological (biological gas exchange and nitrification) soil indicators in two Cambisols in Tercer Frente, Santiago de Cuba, and La Alcarraza, Holguín, during the years 2003–2007. The response to increasing doses of N (0 up to 400 kg ha-1), in the presence of fixed amounts of P (50 kg ha-1) and K (160 kg ha-1), was studied in a randomized block design with four replicates. To obtain coffee yields between 0.50 and 0.84 Mg ha-1, 75 kg ha-1 N are sufficient. In both soils, applications of 100 kg ha-1 N allowed for coffee yields between 1.22 and 1.25 Mg ha-1. With a dose of 153 kg ha-1 N, 1.80 Mg ha-1 coffee yields are obtained, whereas for yields higher than 2 Mg ha-1, it is necessary to apply 200 kg ha-1 N. There was a significant coffee yield increment per each kilogram of N applied, which ranged from 2.13 to 7.80. The proposed doses per site did not affect the microbial activity or soil organic matter. There was a soil pH reduction compared to its initial stage

Estrategia para el aprendizaje activo: Biblioteca audiovisual de casos clínicos reales de la patología cardiovascular más frecuente. Implicaciones para la preparación del examen M.I.R

Ofrecer al alumno una formación práctica y real a partir de situaciones de la práctica clínica diaria. Realizar un repositorio de vídeos y preguntas que crezca cada curso académico. Se pretende que esta colección sirva como modelo para la creación posterior de una aplicación informática que permita la interpretación de cualquier electrocardiograma tras escaneo del mismo en dispositivos tales como móviles o tabletas

Natural stone

Español: La piedra natural constituye un material de construcción de amplio uso en la arquitectura histórica. Los problemas de conservación, en algunos casos alarmantes, que presenta este tipo de material, han propiciado el desarrollo de un campo de investigación científica encaminada a conocer las causas y procesos que han generado estas alteraciones. Esto ha requerido el establecimiento de una metodología con un importante desarrollo y puesta a punto de instrumental en laboratorio. Inglés: Natural stone is a building material widely used in historical architecture. The problems -alarming in some cases- relating to the conservation of this type of material have prompted the development of a field of scientific research aimed at determining the causes and processes responsible for these alterations. This has required the establishment of a methodology with the development and fine-tuning of laboratory instruments