644 research outputs found

    Proposals of a procedure to asses Pollutographs. Application to Murcia's Combined Sewer Overflows (CSOs). Póster

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    Directives 91/271/EEC and 93/481/EEC set norms regarding the management of Combined Sewer Overflows. European Commission monitors the implementation status and implementation programmes. In fact, during the year 2019 all the utilities should be able to quantify the pollution spilled during storm events. And afterwards, plans have to be developed in order to reduce the impact of such events. In this paper, we proposed a method to estimate the transported pollution during events as well as to serve as a tool for developing plans to lessen the corresponding pollution. The procedure is divided into three steps: A. Periodical measurements of all relevant pollutants, e.g. total suspended solids and chemical oxygen demand, in wet and dry weather. Such pollutant “concentrations” are correlated with the turbidity, updating the relation among them [1]. B. Continuous measures of the turbidity. Turbidity is continously register in the sewer areas near overflow spillways. Turbidimeters are a very convenient equipment for this purpose [2]. Actually, it is reliable, its measures are very correlated with the total suspended solid concentration and its maintenance is easy. In this way, combining A. and B. turbidity measures provide us a real-time estimation of the pollutant concentration. on real time. C. Assesment of each catchment hydrograph. Depending on the available data, this step could be based on a design, a measured or a simulated hydrograph. In order to apply this methodology to Murcia’s Combined Sewer System, we have used simulated hydrographs based on real measured rainfall. Murcia’s utility has developed a calibrated SWMM model, and therefore, using the rainfall data, it is possible to estimate hydrographs for all the relevant points of the system. D. Estimation of each catchment pollutograph. Combining the pollutant concentration, estimated in the previous steps, with the hydrographs, we can asses how the mass of pollutants are transported. This information allows us to comply with EU Directives, but it will also be useful to design Murcia’s strategy to minimize environmental impacts

    Flow in a slowly-tapering channel with oscillating walls

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    The flow of a fluid in a channel with walls inclined at an angle to each other is investigated at arbitrary Reynolds number. The flow is driven by an oscillatory motion of the wall incorporating a time-periodic displacement perpendicular to the channel centreline. The gap between the walls varies linearly with distance along the channel and is a prescribed periodic function of time. An approximate solution is constructed assuming that the angle of inclination of the walls is small. At leading order the flow corresponds to that in a channel with parallel, vertically oscillating walls examined by Hall and Papageorgiou \cite{HP}. A careful study of the governing partial differential system for the first order approximation controlling the tapering flow due to the wall inclination is conducted. It is found that as the Reynolds number is increased from zero the tapering flow loses symmetry and undergoes exponential growth in time. The loss of symmetry occurs at a lower Reynolds number than the symmetry-breaking for the parallel-wall flow. A window of asymmetric, time-periodic solutions is found at higher Reynolds number, and these are reached via a quasiperiodic transient from a given set of initial conditions. Beyond this window stability is again lost to exponentially growing solutions as the Reynolds number is increased

    Pandemic influenza control in Europe and the constraints resulting from incoherent public health laws

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    © 2010 Martin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: With the emergence of influenza H1N1v the world is facing its first 21st century global pandemic. Severe Acute Respiratory Syndrome (SARS) and avian influenza H5N1 prompted development of pandemic preparedness plans. National systems of public health law are essential for public health stewardship and for the implementation of public health policy[1]. International coherence will contribute to effective regional and global responses. However little research has been undertaken on how law works as a tool for disease control in Europe. With co-funding from the European Union, we investigated the extent to which laws across Europe support or constrain pandemic preparedness planning, and whether national differences are likely to constrain control efforts. Methods: We undertook a survey of national public health laws across 32 European states using a questionnaire designed around a disease scenario based on pandemic influenza. Questionnaire results were reviewed in workshops, analysing how differences between national laws might support or hinder regional responses to pandemic influenza. Respondents examined the impact of national laws on the movements of information, goods, services and people across borders in a time of pandemic, the capacity for surveillance, case detection, case management and community control, the deployment of strategies of prevention, containment, mitigation and recovery and the identification of commonalities and disconnects across states. Results: Results of this study show differences across Europe in the extent to which national pandemic policy and pandemic plans have been integrated with public health laws. We found significant differences in legislation and in the legitimacy of strategic plans. States differ in the range and the nature of intervention measures authorized by law, the extent to which borders could be closed to movement of persons and goods during a pandemic, and access to healthcare of non-resident persons. Some states propose use of emergency powers that might potentially override human rights protections while other states propose to limit interventions to those authorized by public health laws. Conclusion: These differences could create problems for European strategies if an evolving influenza pandemic results in more serious public health challenges or, indeed, if a novel disease other than influenza emerges with pandemic potential. There is insufficient understanding across Europe of the role and importance of law in pandemic planning. States need to build capacity in public health law to support disease prevention and control policies. Our research suggests that states would welcome further guidance from the EU on management of a pandemic, and guidance to assist in greater commonality of legal approaches across states.Peer reviewe

    Virtual synchronous-machine control of voltage-source converters in a low-voltage microgrid

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    In order to facilitate the further integration of distributed renewable generation into existing power systems, enhanced control schemes for grid-tied power electronic converters are necessary to ensure non-synchronous power sources can provide power and support to the grid. The virtual-synchronous-machine concept proposes the use of control schemes to enable static generators to operate with the dynamics of rotating synchronous generators. In this paper, a control scheme is presented based on the principle of active-power synchronization to regulate the active power of a grid-tied voltage-source converter based on an emulation of the synchronous-machine swing equation. Design of a cascaded inner-loop voltage and resonant current control is presented to regulate the output voltage as specified via the outer-loop virtual-machine control scheme responsible for power regulation. The performance of this control scheme is investigated within the context of microgrid operation for the provision of active and reactive power to the system, and microgrid frequency support. Experimental validation is provided via the use of a 15 kVA three-phase VSC in a 90 kVA 400V microgrid

    Análisis de susceptibilidad a deslizamientos empleando el proceso de jerarquía analítica en una carretera Amazónica del Ecuador

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    The Puyo-Tena roadway is prone to landslides due to the geodynamics, geomorphology, and geological materials of the area (unstable outcrops and strata). In recent years, this problem has persistently caused the road to be partially or completely disabled on numerous occasions. The objective of the research was to generate a cartographic model of landslides susceptibility based on variables such as slope, geological formations, land cover and land use, as well as distances to faults, road, and rivers. The degree of landslides incidence was estimated as the linear combination of the weighted variables using the analytic hierarchy process. The importance of this semi quantitative method lies in its ability to  break down a complex decision problem into a simpler and more coherent decision model. The resulting cartographic model was classified into five susceptibility categories: very low, low, moderate, high, and very high. The results showed that 17 km out of the 80 km of the Puyo-Tena roadway have a high probability of landslides, which is equivalent to 21.25% of the road. Furthermore, within this  percentage, it was determined that there are fifteen regions with a high probability of landslides due to their location in areas with steep slopes, porous and permeable lithology, a  large number of rivers, and agricultural soils. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used for model verification. The verification results showed that the cartographic model for the study area has an accuracy value of 83.7%. The cartographic model of landslide susceptibility will enable relevant decisions to be made to mitigate potential hazards that may endanger transporters, material goods, and residents of the area.  La carretera Puyo-Tena es propensa a deslizamientos de tierra debido a la geodinámica, geomorfología y materiales geológicos de la zona (afloramientos y estratos inestables). En los últimos años, este problema ha provocado de forma persistente la inutilización parcial o total de la carretera en numerosas ocasiones. El objetivo de la investigación fue generar un modelo cartográfico de susceptibilidad a deslizamientos a partir de variables como la pendiente, las formaciones geológicas, la cobertura y uso de la tierra, así como  las distancias a fallas, carretera y ríos. El grado de incidencia de deslizamientos se estimó como la combinación lineal de las variables ponderadas mediante el proceso de jerarquía analítica. La importancia de este método semicuantitativo radica en su capacidad para desagregar un problema de decisión complejo en un modelo de decisión más simple y coherente. El modelo cartográfico resultante se reclasificó en cinco  categorías de susceptibilidad: muy baja, baja, moderada, alta y muy alta.  Los resultados mostraron que 17 km de los 80 km de la carretera Puyo-Tena tienen una alta probabilidad a deslizamientos, lo que equivale a 21,25% de la carretera. Además, dentro de este porcentaje, se determinó que existen quince regiones con alta probabilidad de deslizamientos debido a su ubicación en zonas con fuertes pendientes, litología porosa y permeable, gran cantidad de ríos y suelos agrícolas. Para la verificación del modelo se utilizó el área bajo la curva (en inglés AUC) de la característica operativa del receptor (en inglés ROC). Los resultados de la verificación mostraron  que el modelo cartográfico para el áre de estudio tiene un valor de precisión de 83,7%. El modelo cartográfico de susceptibilidad a deslizamientos permitirá tomar las decisiones pertinentes para mitigar eventos potenciales que puedan poner en peligro a transportistas, bienes materiales y residentes de la zona.

    A Supervised ML Biometric Continuous Authentication System for Industry 4.0

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    Continuous authentication (CA) is a promising approach to authenticate workers and avoid security breaches in the industry, especially in Industry 4.0, where most interaction between workers and devices takes place. However, introducing CA in industries raises the following unsolved questions regarding machine learning (ML) models: its precision and performance; its robustness; and the issue about if or when to retrain the models. To answer these questions, this article explores these issues with a proposed supervised versus nonsupervised ML-based CA system that uses sensors, applications statistics, or speaker data collected by the operator’s devices. Experiments show supervised models with equal error rates of 7.28% using sensors data, 9.29% with statistics, and 0.31% with voice, a significant improvement of 71.97, 62.14, and 97.08%, respectively, over unsupervised models. Voice is the most robust dimension when adding new workers, with less than 2% of false acceptance rate even if workforce size is doubled
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