Implementación de una estrategia didáctica para la enseñanza de inecuaciones en el grado undécimo de la Institución Educativa Versalles mediante el uso de las tecnologías de la información y de la comunicación (TIC)

Las tecnologías de la información y la comunicación en la enseñanza de las matemáticas, se convierten en la actualidad en una de las herramientas más utilizadas para despertar en los estudiantes las ganas y el deseo por aprender. Es así, que este trabajo diseña e implementa una estrategia didáctica de enseñanza de inecuaciones lineales basada en plataformas educativas que permiten la realización de cursos virtuales para los estudiantes del grado undécimo de la Institución Educativa Versalles en el municipio de Santa Bárbara. Se crea un curso virtual y se desarrolla en dos plataformas, Moodle y Erudito; luego, los estudiantes se dividen en dos grupos de trabajo, cada grupo desarrolla los mismos contenidos en una de las plataformas. Se propone una evaluación actitudinal para comparar la percepción de los estudiantes en dos aspectos; el impacto de la estrategia aplicada y la comparación de las plataformas Moodle y Erudito.Abstract: Nowadays, information and communication technologies in mathematics’ teaching has become one of the most used tools for increasing the motivation and desire to learn of the students. Thus, this work designs and develops a didactic strategy for teaching linear inequalities based on educational platforms that allow the creation of virtual courses for students of eleventh degree in Institución Educativa Versalles in Santa Barbara´s municipality. A virtual course is created and developed in two platforms, Moodle and Erudito. Then, the students are divided in two work groups and each one develops the same content in one of the platforms. An attitude test is made in order to compare the perception of the students in two aspects, the impact of the applied strategy and the comparation of the platforms, Moodle and Erudito

Assessment of air management strategies on particulate number and size distributions from a 2-stroke compression-ignition engine operating with gasoline Partially Premixed Combustion concept

[EN] The newly designed partially premixed combustion concept has demonstrated its potential to reduce nitrogen oxides and particulate matter emissions combined with highly indicated efficiencies. However, it is highly dependent of the ignition characteristics of the fuel and the air/fuel mixture preparation. Therefore, the proper selection of an injection strategy, of the combustion chamber design and of the air management strategy are critical to ensuring successful partially premixed combustion operation in the full engine map. The objective of the present investigation is to evaluate the use of multiple air management strategies over the air/fuel effective equivalence ratio (feff) and cylinder charge reactivity and its consequent impact on particle number emissions and particle size distribution. Tests were carried out in a newly designed 2-stroke high-speed direct-injection compression-ignition engine operating with partially premixed combustion concept using 95-research-octane-number gasoline fuel. A scanning mobility particle sizer was used to measure the size distribution of engine-exhaust particles in the range from 6.3 to 237 nm. Three different steady-state operation modes in terms of indicated mean effective pressure and engine speed were investigated. The experiments showed an increase in the particle number emissions and a progressive shift in the particle size toward larger sizes, increasing the accumulation-mode particles and reducing the nucleation-mode particles with the decrease in the differential pressure between intake and exhaust (DP) and the valve overlap period. Finally, the particle formation process was limited by the increase in the exhaust gas recirculation rate.Bermúdez, V.; Ruiz, S.; Novella Rosa, R.; Soto-Izquierdo, L. (2018). Assessment of air management strategies on particulate number and size distributions from a 2-stroke compression-ignition engine operating with gasoline Partially Premixed Combustion concept. International Journal of Engine Research. 1-22. https://doi.org/10.1177/1468087418802706S12

Assessment on the consequences of injection strategies on combustion process and particle size distributions in Euro VI medium-duty diesel engine

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419865652.[EN] Although there are already several works where the influence of injection parameters on exhaust emissions, and specifically on particulate matter emissions, in diesel engines has been evaluated, the diversity in the results that can be found in the literature indicates the need to carry out new experiments that can provide more information about the influence of these parameters on modern diesel engines. This study intends to be placed within this scientific framework, hence a parametric study was carried out based on the independent modification of the main injection timing and the injection pressure with respect to the nominal conditions of a new Euro VI direct injection diesel engine. Four steady-state operation points of the engine map were chosen: 25% load and 950 r/min, 50% load and 1500 r/min, 75% load and 2000 r/min and 100% load and 2200 r/min, where in each of these operation points, the variations of the injection parameters in the study on the combustion process and its consequent impact on the particle size distribution, including an analysis of the geometric mean diameter values, were evaluated. The results showed that the different injection strategies adopted, despite not significantly affecting the engine efficiency, did cause a significant impact on particle number emissions. At the low load operation, the size distribution showed a bimodal structure, and as the main injection timing was delayed and the injection pressure was decreased, the nucleation-mode particle concentration decreased, while the accumulation-mode particle concentration increased. In addition, at medium load, the nucleation-mode particle emission decreased considerably while the accumulation-mode particle emission increased, and this increase was much greater with the main injection timing delay and the injection pressure reduction. Similar behavior was observed at high load, but with a much more prominent pattern.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This investigation has been funded by VOLVO Group Trucks Technology. The authors also acknowledge the Spanish economy and competitiveness ministry for partially supporting this research (HiReCo TRA2014-58870-R).Bermúdez, V.; García Martínez, A.; Villalta-Lara, D.; Soto, L. (2020). Assessment on the consequences of injection strategies on combustion process and particle size distributions in Euro VI medium-duty diesel engine. International Journal of Engine Research. 21(4):683-697. https://doi.org/10.1177/1468087419865652683697214Kemball-Cook, S., Yarwood, G., Johnson, J., Dornblaser, B., & Estes, M. (2015). Evaluating NOx emission inventories for regulatory air quality modeling using satellite and air quality model data. Atmospheric Environment, 117, 1-8. doi:10.1016/j.atmosenv.2015.07.002Paulin, L., & Hansel, N. (2016). Particulate air pollution and impaired lung function. F1000Research, 5, 201. doi:10.12688/f1000research.7108.1Hime, N., Marks, G., & Cowie, C. (2018). A Comparison of the Health Effects of Ambient Particulate Matter Air Pollution from Five Emission Sources. International Journal of Environmental Research and Public Health, 15(6), 1206. doi:10.3390/ijerph15061206Johnson, T., & Joshi, A. (2018). Review of Vehicle Engine Efficiency and Emissions. SAE International Journal of Engines, 11(6), 1307-1330. doi:10.4271/2018-01-0329Wu, Z., Rutland, C. J., & Han, Z. (2017). Numerical optimization of natural gas and diesel dual-fuel combustion for a heavy-duty engine operated at a medium load. International Journal of Engine Research, 19(6), 682-696. doi:10.1177/1468087417729255Lapuerta, M., Hernández, J. J., Rodríguez-Fernández, J., Barba, J., Ramos, A., & Fernández-Rodríguez, D. (2017). Emission benefits from the use of n-butanol blends in a Euro 6 diesel engine. International Journal of Engine Research, 19(10), 1099-1112. doi:10.1177/1468087417742578Chilumukuru, K., Gupta, A., Ruth, M., Cunningham, M., Kothandaraman, G., Cumaranatunge, L., & Hess, H. (2017). Aftertreatment Architecture and Control Methodologies for Future Light Duty Diesel Emission Regulations. SAE International Journal of Engines, 10(4), 1580-1587. doi:10.4271/2017-01-0911Bermúdez, V., Luján, J. M., Piqueras, P., & Campos, D. (2014). Pollutants emission and particle behavior in a pre-turbo aftertreatment light-duty diesel engine. Energy, 66, 509-522. doi:10.1016/j.energy.2014.02.004Lapuerta, M., Ramos, Á., Fernández-Rodríguez, D., & González-García, I. (2018). High-pressure versus low-pressure exhaust gas recirculation in a Euro 6 diesel engine with lean-NOx trap: Effectiveness to reduce NOx emissions. International Journal of Engine Research, 20(1), 155-163. doi:10.1177/1468087418817447Rakopoulos, C. D., Rakopoulos, D. C., Mavropoulos, G. C., & Kosmadakis, G. M. (2018). Investigating the EGR rate and temperature impact on diesel engine combustion and emissions under various injection timings and loads by comprehensive two-zone modeling. Energy, 157, 990-1014. doi:10.1016/j.energy.2018.05.178Du, W., Lou, J., Yan, Y., Bao, W., & Liu, F. (2017). Effects of injection pressure on diesel sprays in constant injection mass condition. Applied Thermal Engineering, 121, 234-241. doi:10.1016/j.applthermaleng.2017.04.075Nishida, K., Zhu, J., Leng, X., & He, Z. (2017). Effects of micro-hole nozzle and ultra-high injection pressure on air entrainment, liquid penetration, flame lift-off and soot formation of diesel spray flame. International Journal of Engine Research, 18(1-2), 51-65. doi:10.1177/1468087416688805Yamasaki, Y., Ikemura, R., & Kaneko, S. (2017). Model-based control of diesel engines with multiple fuel injections. International Journal of Engine Research, 19(2), 257-265. doi:10.1177/1468087417747738Giechaskiel, B., Schiefer, E., Schindler, W., Axmann, H., & Dardiotis, C. (2013). Overview of Soot Emission Measurements Instrumentation: From Smoke and Filter Mass to Particle Number. SAE International Journal of Engines, 6(1), 10-22. doi:10.4271/2013-01-0138Dickau, M., Olfert, J., Stettler, M. E. J., Boies, A., Momenimovahed, A., Thomson, K., … Johnson, M. (2016). Methodology for quantifying the volatile mixing state of an aerosol. Aerosol Science and Technology, 50(8), 759-772. doi:10.1080/02786826.2016.1185509Lähde, T., Rönkkö, T., Virtanen, A., Schuck, T. J., Pirjola, L., Hämeri, K., … Keskinen, J. (2008). Heavy Duty Diesel Engine Exhaust Aerosol Particle and Ion Measurements. Environmental Science & Technology, 43(1), 163-168. doi:10.1021/es801690hSaxena, M. R., & Maurya, R. K. (2017). Effect of premixing ratio, injection timing and compression ratio on nano particle emissions from dual fuel non-road compression ignition engine fueled with gasoline/methanol (port injection) and diesel (direct injection). Fuel, 203, 894-914. doi:10.1016/j.fuel.2017.05.015Gao, J., & Kuo, T.-W. (2018). Toward the accurate prediction of soot in engine applications. International Journal of Engine Research, 20(7), 706-717. doi:10.1177/1468087418773937Zhang, Y., Ghandhi, J., & Rothamer, D. (2017). Comparisons of particle size distribution from conventional and advanced compression ignition combustion strategies. International Journal of Engine Research, 19(7), 699-717. doi:10.1177/1468087417721089Lapuerta, M., Armas, O., & Gómez, A. (2003). Diesel Particle Size Distribution Estimation from Digital Image Analysis. Aerosol Science and Technology, 37(4), 369-381. doi:10.1080/02786820300970Agarwal, A. K., Gupta, T., & Kothari, A. (2011). Particulate emissions from biodiesel vs diesel fuelled compression ignition engine. Renewable and Sustainable Energy Reviews, 15(6), 3278-3300. doi:10.1016/j.rser.2011.04.002Bai, J., & Qiao, X. (2015). Crankcase gaseous and particle emissions in common rail diesel engine. International Journal of Engine Research, 17(2), 179-192. doi:10.1177/1468087414563585Reijnders, J., Boot, M., & de Goey, P. (2018). Particle nucleation-accumulation mode trade-off: A second diesel dilemma? Journal of Aerosol Science, 124, 95-111. doi:10.1016/j.jaerosci.2018.06.013Bonatesta, F., Chiappetta, E., & La Rocca, A. (2014). Part-load particulate matter from a GDI engine and the connection with combustion characteristics. Applied Energy, 124, 366-376. doi:10.1016/j.apenergy.2014.03.030Desantes, J. M., Bermúdez, V., García, A., & Linares, W. G. (2011). A Comprehensive Study of Particle Size Distributions with the Use of PostInjection Strategies in DI Diesel Engines. Aerosol Science and Technology, 45(10), 1161-1175. doi:10.1080/02786826.2011.582898Li, X., Guan, C., Luo, Y., & Huang, Z. (2015). Effect of multiple-injection strategies on diesel engine exhaust particle size and nanostructure. Journal of Aerosol Science, 89, 69-76. doi:10.1016/j.jaerosci.2015.07.008Benajes, J., García, A., Monsalve-Serrano, J., Balloul, I., & Pradel, G. (2017). Evaluating the reactivity controlled compression ignition operating range limits in a high-compression ratio medium-duty diesel engine fueled with biodiesel and ethanol. International Journal of Engine Research, 18(1-2), 66-80. doi:10.1177/1468087416678500Kakaee, A.-H., Nasiri-Toosi, A., Partovi, B., & Paykani, A. (2016). Effects of piston bowl geometry on combustion and emissions characteristics of a natural gas/diesel RCCI engine. Applied Thermal Engineering, 102, 1462-1472. doi:10.1016/j.applthermaleng.2016.03.162Desantes, J. M., Bermúdez, V., Pastor, J. V., & Fuentes, E. (2004). Methodology for measuring exhaust aerosol size distributions from heavy duty diesel engines by means of a scanning mobility particle sizer. Measurement Science and Technology, 15(10), 2083-2098. doi:10.1088/0957-0233/15/10/019Desantes, J. M., Bermúdez, V., Molina, S., & Linares, W. G. (2011). Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions. Measurement Science and Technology, 22(11), 115101. doi:10.1088/0957-0233/22/11/115101Payri, F., Olmeda, P., Martín, J., & García, A. (2011). A complete 0D thermodynamic predictive model for direct injection diesel engines. Applied Energy, 88(12), 4632-4641. doi:10.1016/j.apenergy.2011.06.005Benajes, J. V., López, J. J., Novella, R., & García, A. (2008). ADVANCED METHODOLOGY FOR IMPROVING TESTING EFFICIENCY IN A SINGLE-CYLINDER RESEARCH DIESEL ENGINE. Experimental Techniques, 32(6), 41-47. doi:10.1111/j.1747-1567.2007.00296.xLiu, Q., Fu, J., Zhu, G., Li, Q., Liu, J., Duan, X., & Guo, Q. (2018). Comparative study on thermodynamics, combustion and emissions of turbocharged gasoline direct injection (GDI) engine under NEDC and steady-state conditions. Energy Conversion and Management, 169, 111-123. doi:10.1016/j.enconman.2018.05.047Seong, H. J., & Boehman, A. L. (2012). Studies of soot oxidative reactivity using a diffusion flame burner. Combustion and Flame, 159(5), 1864-1875. doi:10.1016/j.combustflame.2012.01.009Desantes, J. M., Bermúdez, V., García, J. M., & Fuentes, E. (2005). Effects of current engine strategies on the exhaust aerosol particle size distribution from a Heavy-Duty Diesel Engine. Journal of Aerosol Science, 36(10), 1251-1276. doi:10.1016/j.jaerosci.2005.01.002Lucachick, G., Curran, S., Storey, J., Prikhodko, V., & Northrop, W. F. (2016). Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines. Aerosol Science and Technology, 50(5), 436-447. doi:10.1080/02786826.2016.1163320Mohankumar, S., & Senthilkumar, P. (2017). Particulate matter formation and its control methodologies for diesel engine: A comprehensive review. Renewable and Sustainable Energy Reviews, 80, 1227-1238. doi:10.1016/j.rser.2017.05.133Burtscher, H. (2005). Physical characterization of particulate emissions from diesel engines: a review. Journal of Aerosol Science, 36(7), 896-932. doi:10.1016/j.jaerosci.2004.12.00

Impact of injection settings on gaseous emissions and particle size distribution in the dual-mode dual-fuel concept

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419844413.[EN] Reactivity controlled compression ignition concept has been highlighted among the low temperature combustion strategies. However, this combustion strategy presents some problems related to high levels of hydrocarbon and carbon monoxide emissions at low load and high-pressure rise rate at high load. Therefore, to diminish these limitations, the dual-mode dual-fuel concept has been presented as an excellent alternative. This concept uses two fuels of different reactivity and switches from a dual-fuel fully premixed strategy (based on the reactivity controlled compression ignition concept) during low load to a diffusive nature during high load operation. However, the success of dual-mode dual-fuel concept depends to a large extent on the low reactivity/high reactivity fuel ratio and the injection settings. In this study, parametric variations of injection pressure and injection timing were experimentally performed to analyze the effect over each combustion process that encompasses the dual-mode dual-fuel concept and its consequent impact on gaseous and particles emissions, including an analysis of particle size distribution. The experimental results confirm how the use of an adequate injection strategy is indispensable to obtain low exhaust emission and a balance between the different pollutants. In the fully premixed reactivity controlled compression ignition strategy, the particles concentrations were dominated by nucleation mode; however, the increase in injection pressure and the advance of the diesel main injection timing provided a simultaneous reduction of nitrogen oxide and solid particles (accumulation mode). During the highly premixed reactivity controlled compression ignition strategy, the accumulation-mode particles increased, and their concentrations were higher when the diesel main injection timing advanced and injection pressure decreased, as well as there was a slight increase in nitrogen oxide emissions. Finally, in the dual-fuel diffusion strategy, the concentrations of accumulation-mode particles were higher and there was a considerable increase of these particles with the advance of the diesel main injection timing and the reduction of the injection pressure, while the nitrogen oxide emissions decreased.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This investigation has been funded by VOLVO Group Trucks Technology. The authors also acknowledge the Spanish economy and competitiveness ministry for partially supporting this research (HiReCo TRA2014-58870-R).Bermúdez, V.; Macian Martinez, V.; Villalta-Lara, D.; Soto, L. (2020). Impact of injection settings on gaseous emissions and particle size distribution in the dual-mode dual-fuel concept. International Journal of Engine Research. 21(4):561-577. https://doi.org/10.1177/1468087419844413S561577214Oppenauer, K. S., & Alberer, D. (2013). Soot formation and oxidation mechanisms during diesel combustion: Analysis and modeling impacts. International Journal of Engine Research, 15(8), 954-964. doi:10.1177/1468087413502661Rezaei, R., Dinkelacker, F., Tilch, B., Delebinski, T., & Brauer, M. (2016). Phenomenological modeling of combustion and NOx emissions using detailed tabulated chemistry methods in diesel engines. International Journal of Engine Research, 17(8), 846-856. doi:10.1177/1468087415619302Sarangi, A. K., Garner, C. P., McTaggart-Cowan, G. P., Davy, M. H., Wahab, E., & Peckham, M. (2012). The effects of split injections on high exhaust gas recirculation low-temperature diesel engine combustion. International Journal of Engine Research, 14(1), 68-79. doi:10.1177/1468087412450987Shi, L., Xiao, W., Li, M., Lou, L., & Deng, K. (2017). Research on the effects of injection strategy on LTC combustion based on two-stage fuel injection. Energy, 121, 21-31. doi:10.1016/j.energy.2016.12.128Singh, A. P., & Agarwal, A. K. (2012). Combustion characteristics of diesel HCCI engine: An experimental investigation using external mixture formation technique. Applied Energy, 99, 116-125. doi:10.1016/j.apenergy.2012.03.060Lu, X., Han, D., & Huang, Z. (2011). Fuel design and management for the control of advanced compression-ignition combustion modes. Progress in Energy and Combustion Science, 37(6), 741-783. doi:10.1016/j.pecs.2011.03.003Benajes, J., Novella, R., De Lima, D., & Thein, K. (2017). Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine. Applied Energy, 193, 515-530. doi:10.1016/j.apenergy.2017.02.044Benajes, J., García, A., Domenech, V., & Durrett, R. (2013). An investigation of partially premixed compression ignition combustion using gasoline and spark assistance. Applied Thermal Engineering, 52(2), 468-477. doi:10.1016/j.applthermaleng.2012.12.025Benajes, J., García, A., Monsalve-Serrano, J., Balloul, I., & Pradel, G. (2017). Evaluating the reactivity controlled compression ignition operating range limits in a high-compression ratio medium-duty diesel engine fueled with biodiesel and ethanol. International Journal of Engine Research, 18(1-2), 66-80. doi:10.1177/1468087416678500Benajes, J., Molina, S., García, A., & Monsalve-Serrano, J. (2015). Effects of direct injection timing and blending ratio on RCCI combustion with different low reactivity fuels. Energy Conversion and Management, 99, 193-209. doi:10.1016/j.enconman.2015.04.046Kavuri, C., Kokjohn, S. L., Klos, D. T., & Hou, D. (2016). Blending the benefits of reactivity controlled compression ignition and gasoline compression ignition combustion using an adaptive fuel injection system. International Journal of Engine Research, 17(8), 811-824. doi:10.1177/1468087415615255Benajes, J., Pastor, J. V., García, A., & Boronat, V. (2016). A RCCI operational limits assessment in a medium duty compression ignition engine using an adapted compression ratio. Energy Conversion and Management, 126, 497-508. doi:10.1016/j.enconman.2016.08.023Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). Achieving clean and efficient engine operation up to full load by combining optimized RCCI and dual-fuel diesel-gasoline combustion strategies. Energy Conversion and Management, 136, 142-151. doi:10.1016/j.enconman.2017.01.010Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). Gaseous emissions and particle size distribution of dual-mode dual-fuel diesel-gasoline concept from low to full load. Applied Thermal Engineering, 120, 138-149. doi:10.1016/j.applthermaleng.2017.04.005Desantes, J. M., Bermúdez, V., Pastor, J. V., & Fuentes, E. (2004). Methodology for measuring exhaust aerosol size distributions from heavy duty diesel engines by means of a scanning mobility particle sizer. Measurement Science and Technology, 15(10), 2083-2098. doi:10.1088/0957-0233/15/10/019Payri, F., Olmeda, P., Martín, J., & García, A. (2011). A complete 0D thermodynamic predictive model for direct injection diesel engines. Applied Energy, 88(12), 4632-4641. doi:10.1016/j.apenergy.2011.06.005Lapuerta, M., Armas, O., & Gómez, A. (2003). Diesel Particle Size Distribution Estimation from Digital Image Analysis. Aerosol Science and Technology, 37(4), 369-381. doi:10.1080/02786820300970Yinhui, W., Rong, Z., Yanhong, Q., Jianfei, P., Mengren, L., Jianrong, L., … Shijin, S. (2016). The impact of fuel compositions on the particulate emissions of direct injection gasoline engine. Fuel, 166, 543-552. doi:10.1016/j.fuel.2015.11.019Saxena, M. R., & Maurya, R. K. (2017). Effect of premixing ratio, injection timing and compression ratio on nano particle emissions from dual fuel non-road compression ignition engine fueled with gasoline/methanol (port injection) and diesel (direct injection). Fuel, 203, 894-914. doi:10.1016/j.fuel.2017.05.015Agarwal, A. K., Gupta, T., & Kothari, A. (2011). Particulate emissions from biodiesel vs diesel fuelled compression ignition engine. Renewable and Sustainable Energy Reviews, 15(6), 3278-3300. doi:10.1016/j.rser.2011.04.002Bonatesta, F., Chiappetta, E., & La Rocca, A. (2014). Part-load particulate matter from a GDI engine and the connection with combustion characteristics. Applied Energy, 124, 366-376. doi:10.1016/j.apenergy.2014.03.030Reijnders, J., Boot, M., & de Goey, P. (2018). Particle nucleation-accumulation mode trade-off: A second diesel dilemma? Journal of Aerosol Science, 124, 95-111. doi:10.1016/j.jaerosci.2018.06.013Überall, A., Otte, R., Eilts, P., & Krahl, J. (2015). A literature research about particle emissions from engines with direct gasoline injection and the potential to reduce these emissions. Fuel, 147, 203-207. doi:10.1016/j.fuel.2015.01.012Benajes, J. V., López, J. J., Novella, R., & García, A. (2008). ADVANCED METHODOLOGY FOR IMPROVING TESTING EFFICIENCY IN A SINGLE-CYLINDER RESEARCH DIESEL ENGINE. Experimental Techniques, 32(6), 41-47. doi:10.1111/j.1747-1567.2007.00296.xNazemi, M., & Shahbakhti, M. (2016). Modeling and analysis of fuel injection parameters for combustion and performance of an RCCI engine. Applied Energy, 165, 135-150. doi:10.1016/j.apenergy.2015.11.093Jain, A., Singh, A. P., & Agarwal, A. K. (2017). Effect of fuel injection parameters on combustion stability and emissions of a mineral diesel fueled partially premixed charge compression ignition (PCCI) engine. Applied Energy, 190, 658-669. doi:10.1016/j.apenergy.2016.12.164Brückner, C., Pandurangi, S. S., Kyrtatos, P., Bolla, M., Wright, Y. M., & Boulouchos, K. (2017). NOx emissions in direct injection diesel engines – part 1: Development of a phenomenological NOx model using experiments and three-dimensional computational fluid dynamics. International Journal of Engine Research, 19(3), 308-328. doi:10.1177/1468087417704312Desantes, J. M., Benajes, J., García, A., & Monsalve-Serrano, J. (2014). The role of the in-cylinder gas temperature and oxygen concentration over low load reactivity controlled compression ignition combustion efficiency. Energy, 78, 854-868. doi:10.1016/j.energy.2014.10.080Schneider, J., Hock, N., Weimer, S., Borrmann, S., Kirchner, U., Vogt, R., & Scheer, V. (2005). Nucleation Particles in Diesel Exhaust:  Composition Inferred from In Situ Mass Spectrometric Analysis. Environmental Science & Technology, 39(16), 6153-6161. doi:10.1021/es049427mZhang, Y., Ghandhi, J., & Rothamer, D. (2017). Comparisons of particle size distribution from conventional and advanced compression ignition combustion strategies. International Journal of Engine Research, 19(7), 699-717. doi:10.1177/1468087417721089Kosaka, H., Aizawa, T., & Kamimoto, T. (2005). Two-dimensional imaging of ignition and soot formation processes in a diesel flame. International Journal of Engine Research, 6(1), 21-42. doi:10.1243/146808705x7347Corcione, F. E., Merola, S. S., & Vaglieco, B. M. (2002). Evaluation of temporal and spatial distribution of nanometric particles in a diesel engine by broadband optical techniques. International Journal of Engine Research, 3(2), 93-101. doi:10.1243/14680870260127882Li, X., Guan, C., Luo, Y., & Huang, Z. (2015). Effect of multiple-injection strategies on diesel engine exhaust particle size and nanostructure. Journal of Aerosol Science, 89, 69-76. doi:10.1016/j.jaerosci.2015.07.008Seong, H. J., & Boehman, A. L. (2012). Studies of soot oxidative reactivity using a diffusion flame burner. Combustion and Flame, 159(5), 1864-1875. doi:10.1016/j.combustflame.2012.01.009Desantes, J. M., Bermúdez, V., García, A., & Linares, W. G. (2011). A Comprehensive Study of Particle Size Distributions with the Use of PostInjection Strategies in DI Diesel Engines. Aerosol Science and Technology, 45(10), 1161-1175. doi:10.1080/02786826.2011.582898Pickett, L. M., & Siebers, D. L. (2004). Soot in diesel fuel jets: effects of ambient temperature, ambient density, and injection pressure. Combustion and Flame, 138(1-2), 114-135. doi:10.1016/j.combustflame.2004.04.006Matthias, N., Farron, C., Foster, D. E., Andrie, M., Krieger, R., Najt, P., … Zelenyuk, A. (2011). Particulate Matter Sampling and Volatile Organic Compound Removal for Characterization of Spark Ignited Direct Injection Engine Emissions. SAE International Journal of Fuels and Lubricants, 5(1), 399-409. doi:10.4271/2011-01-210

Effects of multiple injection strategies on gaseous emissions and particle size distribution in a two-stroke compression-ignition engine operating with the gasoline partially premixed combustion concept

[EN] In order to improve performance of internal combustion engines and meet the requirements of the new pollutant emission regulations, advanced combustion strategies have been investigated. The newly designed partially premixed combustion concept has demonstrated its potential for reducing NOx and particulate matter emissions combined with high indicated efficiencies while still retaining proper control over combustion process by using different injection strategies. In this study, parametric variations of injection pressure, second injection and third injection timings were experimentally performed to analyze the effect of the injection strategy over the air/fuel mixture process and its consequent impact on gaseous compound emissions and particulate matter emissions including its size distribution. Tests were carried out on a newly designed two-stroke high-speed direct injection compression-ignition engine operating with the partially premixed combustion concept using 95 research octane number gasoline fuel. A scanning particle sizer was used to measure the particles size distribution and the HORIBA 7100DEGR gas analyzer system to determine gaseous emissions. Three different steady-state operation modes in terms of indicated mean effective pressure and engine speed were investigated: 3.5 bar indicated mean effective pressure and 2000 r/min, 5.5 bar indicated mean effective pressure and 2000 r/min, and 5.5 bar indicated mean effective pressure and 2500 r/min. The experimental results confirm how the use of an adequate injection strategy is indispensable to obtain low exhaust emissions values and a balance between the different pollutants. With the increase in the injection pressure and delay in the second injection, it was possible to obtain a trade-off between NOx and particulate matter emission reduction, while there was an increase in hydrocarbon and carbon monoxide emissions under these conditions. In addition, the experiments showed an increase in particle number emissions and a progressive shift in the particles size distribution toward larger sizes, increasing the accumulation-mode particles and reducing the nucleation-mode particles with the decrease in the injection pressure and delay in the third injection.The authors kindly recognize the technical support provided by Mr Pascal Tribotte from RENAULT SAS in the frame of the DREAM-DELTA-68530-13-3205 Project.Bermúdez, V.; Ruiz-Rosales, S.; Novella Rosa, R.; Soto-Izquierdo, L. (2018). Effects of multiple injection strategies on gaseous emissions and particle size distribution in a two-stroke compression-ignition engine operating with the gasoline partially premixed combustion concept. Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering. 233(10):1-19. https://doi.org/10.1177/0954407018802960S1192331

El acceso a la información pública como base para el control social y la protección del patrimonio público

El derecho de acceso a la información pública se erige en una de las bases para el control social de los actos del Estado en su conjunto. Ello no siempre fue así, siendo este derecho más necesario bajo un sistema democrático representativo. Asimismo, en la medida que la ciudadanía accede de mejor manera a la información pública, el patrimonio público puede ser gestionado de mejor forma, garantizándose su intangibilidad. La nueva ley sobre acceso a la información pública probablemente se convertirá en un elemento esencial para garantizar la vigencia de dicho derecho y de paso para proteger el patrimonio público

Analysis of Regulated Pollutant Emissions and Aftertreatment Efficiency in a GTDi Engine Using Different SOI Strategies

[EN] In order to improve performance and minimize pollutant emissions in gasoline turbocharged direct-injection (GTDi) engines, different injection strategies and technologies are being investigated. The inclusion of exhaust gas recirculation (EGR) and the variation of the start of injection (SOI) are some of these strategies that can influence the air-to-fuel (AF) mixture formation and consequently in the combustion process and pollutant emissions. This article presents a complete study of the engine performance, pollutant emissions and aftertreatment efficiency that produces the SOI variation with a fixed EGR rate in a 4-cylinder, turbocharged, gasoline direct-injection engine with 2.0 L displacement. The equipment used in this study are TSI-EEPS for particle measurement and HORIBA MEXA 1230-PM for soot measurement being HORIBA MEXA 7100-DEGR with a heated line selector the system employed for regulated gaseous emission measurement and aftertreatment evaluation. The experimental results confirm how the use of an adequate SOI strategy is indispensable to obtain low exhaust emissions values and a balance between the different pollutants. There was found a slight reduction in brake specific fuel consumption (BSFC) with the SOI advance. The experiments showed a decrease in CO, a non-sensible variation of THC and an increase in NOx emissions with SOI delay. Additionally, a significant increase in particle emissions was observed with early SOIs. Finally, with the SOI delay the aftertreatment performance revealed an increase in the oxidation of CO and a decrease in the reduction of NOx.The equipment used in this work has been partially supported by FEDER project funds "Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)", framed in the operational program of singular scientific and technical infrastructure of the Ministry of Science and Innovation of Spain.Bermúdez, V.; Luján, JM.; Climent, H.; Soto-Izquierdo, L.; Campos-Navarro, D. (2018). Analysis of Regulated Pollutant Emissions and Aftertreatment Efficiency in a GTDi Engine Using Different SOI Strategies. SAE International Journal of Engines. 11(3):363-382. https://doi.org/10.4271/03-11-03-0025S36338211

Pollutant emissions from Euro 6 light duty vehicle tested under steady state and transient operation on a roller test bench with hydrogenated paraffinic and biodiesel fuels

[EN] The effort to implement more environmental-friendly fuels has been enhanced not only by the desire to reduce the greenhouse effects but also for public health issues. This paper studies the effects on pollutant emissions from a light-duty Euro 6 vehicle with four types of fuel: diesel (fossil origin, used as reference), biodiesel (renewable origin), Gas-to-Liquid (fossil origin) and farnesane (renewable origin). Both stationary engine and real-world driving cycles are studied. First, each fuel was tested in stationary modes in a vehicle test-bench and then tested in a realistic driving cycle with the same vehicle. This allows the separation the transient effects of the driving cycle from stationary results. Stationary tests lead to engine emission maps and driving cycle tests allow weighting the importance of each stationary condition during a realistic route. Instantaneous and cumulative CO, THC (total hydrocarbon), NOx and PN (particle number) emissions on route were obtained. The fuel that presented a highest level of emissions at stationary conditions was, for CO, diesel, for THC, diesel, for NOx, biodiesel and for PN, diesel. The behaviour of fuels during the driving cycles, from less pollutant to more pollutant, was: for CO, diesel, farnesane, GTL and biodiesel; for THC, GTL, farnesane, biodiesel, diesel. For NOx, farnesane and diesel (very similar values), GTL and biodiesel; for PN, GTL, biodiesel, farnesane and diesel.The authors would like to thank the funding provided by the Spanish Ministry of Science for RECUPERA project (Ref. RTI2018-095923-B-C21) and infrastructure (Ref. EQC2019-005675-P) , the donation of Farnesane fuel by AMYRIS, the donation of GTL fuel by SASOL and the discount provided by REPSOL in the purchase of diesel and biodiesel fuels.Fernández-Yáñez, P.; Soriano, JA.; Soto, F.; Armas, O.; Pla Moreno, B.; Bermúdez, V. (2022). Pollutant emissions from Euro 6 light duty vehicle tested under steady state and transient operation on a roller test bench with hydrogenated paraffinic and biodiesel fuels. Fuel. 323:1-12. https://doi.org/10.1016/j.fuel.2022.12417311232

Trends of Rural Tropospheric Ozone at the Northwest of the Iberian Peninsula

Tropospheric ozone levels around urban and suburban areas at Europe and North America had increased during 80's–90's, until the application of NOx reduction strategies. However, as it was expected, this ozone depletion was not proportional to the emissions reduction. On the other hand, rural ozone levels show different trends, with peaks reduction and average increments; this different evolution could be explained by either emission changes or climate variability in a region. In this work, trends of tropospheric ozone episodes at rural sites in the northwest of the Iberian Peninsula were analyzed and compared to others observed in different regions of the Atlantic European coast. Special interest was focused on the air quality sites characterization, in order to guarantee their rural character in terms of air quality. Both episodic local meteorological and air quality measurements along five years were considered, in order to study possible meteorological influences in ozone levels, different to other European Atlantic regions

Low temperature regeneration of activated carbons using microwaves: Revising conventional wisdom

[EN] The purpose of this work was to explore the application of microwaves for the low temperature regeneration of activated carbons saturated with a pharmaceutical compound (promethazine). Contrary to expectations, microwave-assisted regeneration did not lead to better results than those obtained under conventional electric heating. At low temperatures the regeneration was incomplete either under microwave and conventional heating, being this attributed to the insufficient input energy. At mild temperatures, a fall in the adsorption capacity upon cycling was obtained in both devices, although this was much more pronounced for the microwave. These results contrast with previous studies on the benefits of microwaves for the regeneration of carbon materials. The fall in the adsorption capacity after regeneration was due to the thermal cracking of the adsorbed molecules inside the carbon porous network, although this effect applies to both devices. When microwaves are used, along with the thermal heating of the carbon bed, a fraction of the microwave energy seemed to be directly used in the decomposition of promethazine through the excitation of the molecular bonds by microwaves (microwave-lysis). These results point out that the nature of the adsorbate and its ability to interact with microwave are key factors that control the application of microwaves for regeneration of exhausted activated carbons.EÇ thanks The Council of Higher Education of Turkey (YÖK) for supporting her stay at INCAR (Oviedo) and the financial support of Istanbul University Research Fund (Project 3991) for her PhD thesis. JMB acknowledges CSIC for a JAE predoctoral fellowship. COA thanks the financial support of the projects CTM2008-01956 and CSIC-200980I131.Peer reviewe