Comunicaciones Wi-Fi de bajo consumo e inmunes a ataques de denegación de servicio (DoS) para redes de sensores inalámbricos

Comunicación presentada en el VII Congreso Nacional de I+D en Defensa y Seguridad (DESEi+d 2019), Escuela de Suboficiales de la Armada, San Fernando (Cádiz), 19-21 de noviembre 2019.La transformación digital del control y monitorización de los sistemas físicos se ha denominado paradigma IoT (Internet of Things), donde la conectividad de cualquier tipo de dispositivo es uno de los elementos principales. Uno de sus campos de aplicación es la sensorización de sistemas físicos (domóticos, industriales, vehículos de transporte, etc.) donde se establecen unos requisitos de comunicaciones de bajo consumo y gran alcance. Estas tecnologías de comunicación LPWAN se han extendido fundamentalmente en tres modelos: Sigfox, LoRaWAN y NB-IoT. Su uso está limitado al coste económico del servicio de datos (cuota por sensor conectado) y la cobertura de estaciones base. Este trabajo presenta un nuevo sistema de comunicaciones patentado aplicable a chipsets Wi-Fi (IEEE 802.11), proporcionando un bajo consumo en los sensores, cobertura de varios kilómetros y coste de comunicaciones por sensor nulo. El sistema consta de una estación base que recibe paquetes IEEE 802.11 emitidos desde los sensores con unas características que permiten superar los problemas de seguridad del estándar WPA2 actual (ataques de desautenticación Wi-Fi, cracking de contraseñas WPA2-PSK, etc.). Para ello se emplean enlaces Wi-Fi no asociados y cifrado de los datos (AES) con claves preinstaladas y reconfigurables para cada escenario de uso. Como prueba de concepto, se presenta una prueba piloto consistente en el despliegue de un prototipo de estación base en un entorno forestal de montaña que obtiene medidas de temperatura y humedad de una serie de sensores desplegados en la zona. La estación base prototipo recibe las transmisiones de los sensores a distancias de 3 km con visión directa (sin obstáculos opacos a la banda de 2.4 GHz). Los sensores presentan un bajo consumo de energía en la transmisión de datos al combinar el sistema de comunicaciones patentando y el uso del chipset Wi-Fi del SoC (System on Chip) ESP8266

An Unusual Case of Locally Advanced Glycogen-Rich Clear Cell Carcinoma of the Breast

Glycogen-rich clear cell (GRCC) is a rare subtype of breast carcinoma characterized by carcinoma cells containing an optically clear cytoplasm and intracytoplasmic glycogen. We present the case of a 55-year-old woman with a palpable mass in the right breast and clinical signs of locally advanced breast cancer (LABC). The diagnosis of GRCC carcinoma was based on certain histopathological characteristics of the tumor and immunohistochemical analysis. To our knowledge, this is the first case of GRCC LABC with intratumoral calcifications. There is no evidence of recurrence or metastatic disease after 14 months’ follow-up

Stability and chaotic behavior of a PID controlled inverted pendulum subjected to harmonic base excitations by using the normal form theory

In this paper we investigate the stability and the onset of chaotic oscillations around the pointing-up position for a simple inverted pendulum that is driven by a control torque and is harmonically excited in the vertical and horizontal directions. The driven control torque is defined as a proportional plus integral plus derivative (PID) control of the deviation angle with respect to the pointing-down equilibrium position. The parameters of the PID controller are tuned by using the Routh criterion to obtain a stable weak focus around the pointing-up position, whose stability is investigated by using the normal form theory. The normal form theory is also used to deduce a simplified mathematical model that can be resolved analytically and compared with the numerical simulation of the complete mathematical model. From the harmonic prescribed motions for the pendulum base, necessary conditions for chaotic motion are deduced by means of the Melnikov function. When the pendulum is close to the unstable pointing-up position, the PID parameters are changed and the chaotic motion is destroyed, which is achieved by employing very small control signals even in the presence of random noise. The results of the analytical calculations are verified by full numerical simulations

Impact of Exhaust Gas Recirculation on Gaseous Emissions of Turbocharged Spark-Ignition Engines

[EN] Exhaust gas recirculation is one of the technologies that can be used to improve the efficiency of spark-ignition engines. However, apart from fuel consumption reduction, this technology has a significant impact on exhaust gaseous emissions, inducing a significant reduction in nitrogen oxides and an increase in unburned hydrocarbons and carbon monoxide, which can affect operation of the aftertreatment system. In order to evaluate these effects, data extracted from design of experiments done on a multi-cylinder 1.3 L turbocharged spark-ignition engine with variable valve timing and low-pressure exhaust gas recirculation (EGR) are used. The test campaign covers the area of interest for the engine to be used in new-generation hybrid electric platforms. In general, external EGR provides an approximately linear decrease of nitrogen oxides and deterioration of unburned hydrocarbon emissions due to thermal and flame quenching effects. At low load, the impact on emissions is directly linked to actuation of the variable valve timing system due to the interaction of EGR with internal residuals. For the same external EGR rate, running with high valve overlap increases the amount of internal residuals trapped inside the cylinder, slowing down combustion and increasing Unburnt hydrocarbon (HC) emissions. However, low valve overlap (i.e., low internal residuals) operation implies a decrease in oxygen concentration in the exhaust line for the same air-fuel ratio inside the cylinders. At high load, interaction with the variable valve timing system is reduced, and general trends of HC increase and of oxygen and carbon monoxide decrease appear as EGR is introduced. Finally, a simple stoichiometric model evaluates the potential performance of a catalyst targeted for EGR operation. The results highlight that the decrease of nitrogen oxides and oxygen availability together with the increase of unburned hydrocarbons results in a huge reduction of the margin in oxygen availability to achieve a complete oxidation from a theoretical perspective. This implies the need to rely on the oxygen storage capability of the catalyst or the possibility to control at slightly lean conditions, taking advantage of the nitrogen oxide reduction at engine-out with EGR.Piqueras, P.; De La Morena, J.; Sanchis-Pacheco, EJ.; Pitarch-Berná, R. (2020). Impact of Exhaust Gas Recirculation on Gaseous Emissions of Turbocharged Spark-Ignition Engines. Applied Sciences. 10(21):1-17. https://doi.org/10.3390/app10217634S1171021Kolodziej, C. P., Pamminger, M., Sevik, J., Wallner, T., Wagnon, S. W., & Pitz, W. J. (2017). Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion. SAE International Journal of Fuels and Lubricants, 10(1), 82-94. doi:10.4271/2017-01-0671Sjerić, M., Taritaš, I., Tomić, R., Blažić, M., Kozarac, D., & Lulić, Z. (2016). Efficiency improvement of a spark-ignition engine at full load conditions using exhaust gas recirculation and variable geometry turbocharger – Numerical study. Energy Conversion and Management, 125, 26-39. doi:10.1016/j.enconman.2016.02.047Grover, Jr., R. O., & Cleary, D. (2013). Correlating Measured Combustion Performance with CFD Predicted In-Cylinder Flows for a Spark-Ignition Direct-Injection (SIDI) Engine with Enhanced Charge Motion. SAE Technical Paper Series. doi:10.4271/2013-01-1090Costa, M., Catapano, F., Sementa, P., Sorge, U., & Vaglieco, B. M. (2016). Mixture preparation and combustion in a GDI engine under stoichiometric or lean charge: an experimental and numerical study on an optically accessible engine. Applied Energy, 180, 86-103. doi:10.1016/j.apenergy.2016.07.089Alagumalai, A. (2014). Internal combustion engines: Progress and prospects. Renewable and Sustainable Energy Reviews, 38, 561-571. doi:10.1016/j.rser.2014.06.014Dong, X., Wang, B., Yip, H. L., & Chan, Q. N. (2019). CO2 Emission of Electric and Gasoline Vehicles under Various Road Conditions for China, Japan, Europe and World Average—Prediction through Year 2040. Applied Sciences, 9(11), 2295. doi:10.3390/app9112295Vafamehr, H., Cairns, A., Sampson, O., & Koupaie, M. M. (2016). The competing chemical and physical effects of transient fuel enrichment on heavy knock in an optical spark ignition engine. Applied Energy, 179, 687-697. doi:10.1016/j.apenergy.2016.07.038Gröger, O., Gasteiger, H. A., & Suchsland, J.-P. (2015). Review—Electromobility: Batteries or Fuel Cells? Journal of The Electrochemical Society, 162(14), A2605-A2622. doi:10.1149/2.0211514jesPham, A., & Jeftic, M. (2018). Characterization of Gaseous Emissions from Blended Plug-In Hybrid Electric Vehicles during High-Power Cold-Starts. SAE Technical Paper Series. doi:10.4271/2018-01-0428Yamada, H., Inomata, S., & Tanimoto, H. (2017). Particle and VOC Emissions from Stoichiometric Gasoline Direct Injection Vehicles and Correlation Between Particle Number and Mass Emissions. Emission Control Science and Technology, 3(2), 135-141. doi:10.1007/s40825-016-0060-0Zinola, S., Raux, S., & Leblanc, M. (2016). Persistent Particle Number Emissions Sources at the Tailpipe of Combustion Engines. SAE Technical Paper Series. doi:10.4271/2016-01-2283Xie, F., Li, X., Su, Y., Hong, W., Jiang, B., & Han, L. (2016). Influence of air and EGR dilutions on improving performance of a high compression ratio spark-ignition engine fueled with methanol at light load. Applied Thermal Engineering, 94, 559-567. doi:10.1016/j.applthermaleng.2015.10.046Wei, H., Zhu, T., Shu, G., Tan, L., & Wang, Y. (2012). Gasoline engine exhaust gas recirculation – A review. Applied Energy, 99, 534-544. doi:10.1016/j.apenergy.2012.05.011Ghazikhani, M., Feyz, M. E., & Joharchi, A. (2010). Experimental investigation of the Exhaust Gas Recirculation effects on irreversibility and Brake Specific Fuel Consumption of indirect injection diesel engines. Applied Thermal Engineering, 30(13), 1711-1718. doi:10.1016/j.applthermaleng.2010.03.030Al-Qurashi, K., Lueking, A. D., & Boehman, A. L. (2011). The deconvolution of the thermal, dilution, and chemical effects of exhaust gas recirculation (EGR) on the reactivity of engine and flame soot. Combustion and Flame, 158(9), 1696-1704. doi:10.1016/j.combustflame.2011.02.006Ladommatos, N., Abdelhalim, S. M., Zhao, H., & Hu., Z. (1998). Effects of EGR on Heat Release in Diesel Combustion. SAE Technical Paper Series. doi:10.4271/980184Li, T., Wu, D., & Xu, M. (2013). Thermodynamic analysis of EGR effects on the first and second law efficiencies of a boosted spark-ignited direct-injection gasoline engine. Energy Conversion and Management, 70, 130-138. doi:10.1016/j.enconman.2013.03.001Roy, M. M., Tomita, E., Kawahara, N., Harada, Y., & Sakane, A. (2011). Comparison of performance and emissions of a supercharged dual-fuel engine fueled by hydrogen and hydrogen-containing gaseous fuels. International Journal of Hydrogen Energy, 36(12), 7339-7352. doi:10.1016/j.ijhydene.2011.03.070Wang, Zhang, Wang, Han, & Chen. (2019). Numerical Simulation of Knock Combustion in a Downsizing Turbocharged Gasoline Direct Injection Engine. Applied Sciences, 9(19), 4133. doi:10.3390/app9194133Caton, J. A. (2012). The thermodynamic characteristics of high efficiency, internal-combustion engines. Energy Conversion and Management, 58, 84-93. doi:10.1016/j.enconman.2012.01.005Su, J., Xu, M., Li, T., Gao, Y., & Wang, J. (2014). Combined effects of cooled EGR and a higher geometric compression ratio on thermal efficiency improvement of a downsized boosted spark-ignition direct-injection engine. Energy Conversion and Management, 78, 65-73. doi:10.1016/j.enconman.2013.10.041Gu, X., Huang, Z., Cai, J., Gong, J., Wu, X., & Lee, C. (2012). Emission characteristics of a spark-ignition engine fuelled with gasoline-n-butanol blends in combination with EGR. Fuel, 93, 611-617. doi:10.1016/j.fuel.2011.11.040Galloni, E. (2009). Analyses about parameters that affect cyclic variation in a spark ignition engine. Applied Thermal Engineering, 29(5-6), 1131-1137. doi:10.1016/j.applthermaleng.2008.06.001Bermúdez, V., Luján, J. M., Climent, H., & Campos, D. (2015). Assessment of pollutants emission and aftertreatment efficiency in a GTDi engine including cooled LP-EGR system under different steady-state operating conditions. Applied Energy, 158, 459-473. doi:10.1016/j.apenergy.2015.08.071Park, C., Kim, S., Kim, H., & Moriyoshi, Y. (2012). Stratified lean combustion characteristics of a spray-guided combustion system in a gasoline direct injection engine. Energy, 41(1), 401-407. doi:10.1016/j.energy.2012.02.060Galindo, J., Navarro, R., Tarí, D., & Moya, F. (2020). Development of an experimental test bench and a psychrometric model for assessing condensation on a low-pressure exhaust gas recirculation cooler. International Journal of Engine Research, 22(5), 1540-1550. doi:10.1177/1468087420909735Luján, J. M., Dolz, V., Monsalve-Serrano, J., & Bernal Maldonado, M. A. (2019). High-pressure exhaust gas recirculation line condensation model of an internal combustion diesel engine operating at cold conditions. International Journal of Engine Research, 22(2), 407-416. doi:10.1177/1468087419868026Boccardi, S., Catapano, F., Costa, M., Sementa, P., Sorge, U., & Vaglieco, B. M. (2016). Optimization of a GDI engine operation in the absence of knocking through numerical 1D and 3D modeling. Advances in Engineering Software, 95, 38-50. doi:10.1016/j.advengsoft.2016.01.023Pla, B., De La Morena, J., Bares, P., & Jiménez, I. (2020). Knock Analysis in the Crank Angle Domain for Low-Knocking Cycles Detection. SAE Technical Paper Series. doi:10.4271/2020-01-0549Serrano, J., Climent, H., Navarro, R., & González-Domínguez, D. (2020). Methodology to Standardize and Improve the Calibration Process of a 1D Model of a GTDI Engine. SAE Technical Paper Series. doi:10.4271/2020-01-1008Nishiyama, A., Le, M. K., Furui, T., & Ikeda, Y. (2019). The Relationship between In-Cylinder Flow-Field near Spark Plug Areas, the Spark Behavior, and the Combustion Performance inside an Optical S.I. Engine. Applied Sciences, 9(8), 1545. doi:10.3390/app908154

Sistema de Información Geográfica (GIS) y mensajería para smartphones en ausencia de infraestructura de telefonía móvil

X Congreso Nacional de I+D en Defensa y Seguridad (DESEi+d 2023). Cartagena (Murcia). 14-16 Noviembre 2023.La adopción del uso de smartphones en la sociedad en la última década está propiciando su introducción como herramienta de trabajo en ámbitos hasta ahora no contemplados, como son Defensa y Cuerpos y Fuerzas de Seguridad del Estado. Este trabajo presenta un nuevo sistema de información geográfica que permite visualizar en un mapa las ubicaciones de un conjunto de smartphones y un mecanismo de mensajería privada con los mismos. Este sistema funciona con un sistema de comunicaciones Wi-Fi propietario y patentado por la Universidad de Alicante lo que permite la independencia de operadores de telefonía móvil. Para ello la arquitectura de red emplea repetidores propietarios basados en chipsets Wi-Fi, lo que presenta un coste económico muy inferior a otras soluciones del mercado, como son las redes privadas 4G o 5G. Se ha desarrollado un prototipo demostrativo para su aplicación en la gestión de efectivos en extinción de incendios forestales, permitiendo un área de operación de hasta 600 km2

Exploring the Chemistry of the Mechanical Bond: Synthesis of a [2]Rotaxane through Multicomponent Reactions

© 2023 The Authors. Published by American Chemical Society and Division of Chemical Education, Inc. This manuscript version is made available under the CC-BY 4.0 license https://creativecommons.org/licenses/by/4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in Journal of Chemical Education. To access the final edited and published work see https://doi.org/10.1021/acs.jchemed.3c00163The synthesis of a [2]rotaxane through three- or five-component coupling reactions has been adapted to an organic chemistry experiment for upper-division students. The experimental procedure addresses the search for the most favorable reaction conditions for the synthesis of the interlocked compound, which is obtained in a yield of up to 71%. Moreover, the interlocked nature of the rotaxane is proven by NMR spectroscopy. The content of the sessions has been designed on the basis of a proactive methodology whereby upper-division undergraduate students have a dynamic role. The laboratory experience not only introduces students to the chemistry of the mechanical bond but also reinforces their previous knowledge of basic organic laboratory procedures and their skills with structural elucidation techniques such as NMR and FT-IR spectroscopies. The experiment has been designed in such a customizable way that both experimental procedures and laboratory material can be adapted to a wide range of undergraduate course curricula