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Este artículo presenta el estado actual de las técnicas de inteligencia artificial y su aplicación al campo de la detección y diagnóstico de fallas en sistemas dinámicos. Inicialmente, se hace una breve descripción de lo que se considera un mecanismo de detección y diagnóstico de fallas, y se explican los enfoques actuales de estudio y aplicación de tales mecanismos. Posteriormente, se presentan los resultados más importantes de las diferentes técnicas de inteligencia artificial aplicadas a la detección y diagnóstico de fallas. Finalmente, se presenta un análisis comparativo con base en las características deseables de los mecanismos de detección y diagnóstico de fallas. El artículo concluye mencionando los beneficios de la clasificación de las técnicas presentadas y enumerando las posibles vías hacia donde debe ir la investigación en este campo.

espanolSe presentan los resultados de un estudio sobre la significancia y la optimizacion de algunas variables (granulometria, velocidad de aire, contenido de biomasa y disposicion del reactor) en el poder calorifico del gas de sintesis obtenido de la gasificacion de biomasa (carbon vegetal y cuesco de palma africana). Mediante un diseno de experimento se evaluaron las cuatro variables que oscilaban entre 8-13mm para la granulometria, 0.8-1.4m/s para la velocidad del aire, 0-100 para el contenido de biomasa y ascendente-descendente para la disposicion del reactor. Se encontro que los factores correspondientes a la granulometria y el contenido de biomasa resultan ser los mas significativos en el poder calorifico del gas. Un poder calorifico maximo de 3.84MJ/Nm3 se obtuvo con la disposicion descendente del reactor, alimentacion de carbon vegetal con granulometria de 13mm y suministro maximo de flujo de aire. La verificacion del punto optimo de operacion mostro que tales condiciones de operacion favorecian la produccion de un gas con un alto poder calorifico. EnglishThe results of study on the significance and the optimization of some variables (particle size, air flow, biomass content and reactor disposition) in the calorific value of the synthesis gas obtained by gasification process of biomass (vegetal coal and biomass African palm) is presented. The four variables ranged from 8-13mm for the particle size, 0.8-1.4m/s for air flow, 0-100 for biomass content and updraft-downdraft disposition for the type of reactor were evaluated by an experimental design. It was found that the particle size and biomass content are the most significant factors to maximize the output calorific value of syngas. A maximum calorific value of 3.84MJ/Nm3 was obtained using the downdraft reactor with 13mm particle size and maximum air flow supply. The verification of the optimum operating point under these conditions showed that such operating conditions favored the production of a gas with high calorific value.

This work is the result to the study a different systems of exhaust pipes. The manufacturers of motorbike use a system with several volumes to reduce noise and use a catalyst to reduce emissions. In contrast, the manufacturers of exhaust system decided made a system using a perforated pipe and a rock wool to noise reducing. This system changes the pressure drop and temperature of exhaust gases and, therefore, request a different composition of catalyst.In this communication, it is shown the tests released in a test bench according with the cycle WLTC and the limits are the defined for EURO3. Where, we have changed the type of catalyst, the diameter of the end pipe and the calibration of electronic control unit of engine in order to measure following the test of homologation.The results of the different experiments indicate is very important the pressure drop in the replace exhaust system must be similar to the original system. The composition of the catalyst and the operating temperature are critical to reduce the emissions and the calibration of engine is the main influence. Keywords: Exhaust systems, Catalyst, Regulatory emissions, WLTC

Extreme events usually cause numerous economic and social losses, especially in vulnerable countries, such as Brazil. Understanding whether the evolution of Earth System Models (ESMs) from Coupled Model Intercomparison Project (CMIP) improves the representation of extreme events and investigating their future change is fundamental because device policies of adaptation and mitigation to climate change generally consider the results of the most recent generation of ESMs. This study analyzes the performance of a subset of 40 ESMs from CMIP3, CMIP5, and CMIP6 in simulating eight extreme precipitation climate indices over Brazil during 1981–2000 and also estimates their projected changes for the middle (2046–2065) and far future (2081–2 100) under the worst-case scenario for each CMIP generation. Results reveal that CDD are the most challenging precipitation index to be simulated, while the best ones were PRCPTOT and R20mm. The model performance shows that CMIP3 has the best skill for Northeast Brazil, CMIP5 for Center-West, and CMIP6 for North, Southeast and South regions. Thus, at least for Brazil, the evolution of the ESMs from CMIP did not reflect a substantial improvement in the representation of precipitation climate extremes over all Brazilian regions. In addition, all the models across CMIP generations have difficulty in simulating the observed trends. This indicate that improvements are still needed in CMIP models. Despite the relative low performance in the historical climate, the climate projections indicate a consensus signal among most of precipitation climate extremes and CMIP generations, which increase its reliability. Overall, the extreme precipitation events are projected to be more severe, frequent, and long-lasting in all Brazilian regions, with the more pronounce changes expected in heavy rainfall and severe droughts in the central northern portion of Brazil and in the southern sector.

This work focuses on Vacuum Membrane Distillation (VMD) and Sweeping Gas Membrane Distillation (SGMD) as a separating technique of ethanol from aqueous solutions. VMD was studied at moderate temperature (30, 40 and 50°C) and pressure (0.11, 0.20 and 0.30 atm) conditions, whereas SGMD was studied at different temperatures (50 and 70°C) and air-flow rates (10x10-6 and 20x10-6 m³·min-1). These techniques were experimentally studied using prepared ethanol-water solutions and fermented broths, with ethanol at 10% w/w. Under these operating conditions and using prepared ethanol-water solutions, an average total flux of 22.61 and 1.6 kg·m-2·h-1, and concentration factors of 2.3 and 1.7 were obtained for VMD and SGMD, respectively. For fermented broths, total flux of 17.66 and 0.9 kg·m-2·h-1, and concentration factors of 1.8 and 1.9 were obtained for VMD and SGMD, respectively. The fouling impact was also studied, finding a significant effect of pressure (vacuum) for VMD technique; mainly due to the biomass presence in the solution. Experimental results show that applying pressurization/depressurization cycles decreases membrane fouling, stabilizing flux and concentration in the permeate. While for SGMD configuration, the incidence of fouling was significantly lower.

Spain has been pinpointed as one of the European countries at major risk of extreme urban events. Thus, Spanish cities pursue new urban plans to increase their resilience. In this scenario, experiences in the implementation of Sustainable Urban Drainage Systems (SUDS) have increased substantially. Nevertheless, few cities have developed a global urban strategy for SUDS, lacking, in many cases, a method to identify strategic areas to maximize their synergetic benefits. Furthermore, there is still a need for a holistic Multicriteria Decision Analysis (MCDA) framework that considers the four pillars of SUDS design. The city of Gijón, NW Spain, has been selected as a case study due to its environmental and climatic stresses. This research presents the methodology developed for this city, which aims to analyze the need for SUDS implementation throughout the identification of strategic areas. With this aim, a combination of Geographic Information System (GIS) software and the MCDA Analytical Hierarchical Process (AHP) were proposed. The results show the potential for SUDS’ implementation, according to nine criteria related to the SUDS’ design pillars. We found that the areas where the implementation of SUDS would bring the greatest functional, environmental and social benefits are mainly located in consolidated urban areas.

Supercapacitors are common devices in electrical circuits that produce electrical pulses at high power levels in short periods of time. Electrodes for supercapacitors were prepared with activated carbon. Activated carbon was obtained from cassava peels treated by chemical activation with potassium hydroxide (KOH) and phosphoric acid (H3PO4), each at two different concentrations and at one carbonization temperature. Electrochemical performance of the prepared electrodes was obtained by means of cyclic voltammetry and galvanostatic charge-discharge in a 3-electrode system with an electrolytic solution of sulfuric acid (H2SO4) 1 M. Cyclic voltammetry allowed to indentify a behavior of supercapacitors in a potential window of -0.4V to 0.6V. Activated carbon derived from cassava peel with the highest specific surface area (398.46 m2/g) has exhibited the maximum specific capacitance of 64.18 F/g.

Abstract In this study, we analyzed the optimal location and sizing of distributed generators (DGs) in radial distributed networks using a hybrid master-slave metaheuristic technique. The master stage corresponds to the selection of suitable points for the locations of the DGs, whereas the slave stage is the optimal dimensioning problem. The Chu-Beasley genetic algorithm (CBGA) is employed to solve the master stage, and the optimal power flow (OPF) method via the vortex search algorithm (VSA) is employed to solve the slave stage. The OPF solution from the VSA technique uses a successive approximation power flow to determine the voltage profiles and power losses by guaranteeing the energy balance in all the nodes of the network. The conventional and widely used 33- and 69-node test feeders are used to validate the hybrid CBGA-VSA for analyzing the optimal location and sizing of the DGs in the distribution networks using MATLAB software. The numerical results demonstrate the efficiency of the proposed optimization method in terms of power loss reduction as compared with the results available in the literature. An additional 24-h dimensioning analysis is included for demonstrating the efficiency and applicability of the proposed methodology for daily operations with renewable generation.