Photonic heterostructures with Levy-type disorder: statistics of coherent transmission

We study the electromagnetic transmission $T$ through one-dimensional (1D) photonic heterostructures whose random layer thicknesses follow a long-tailed distribution --L\'evy-type distribution. Based on recent predictions made for 1D coherent transport with L\'evy-type disorder, we show numerically that for a system of length $L$ (i) the average $\propto L^\alpha$ for $0 \propto L$ for $1\le\alpha<2$, $\alpha$ being the exponent of the power-law decay of the layer-thickness probability distribution; and (ii) the transmission distribution $P(T)$ is independent of the angle of incidence and frequency of the electromagnetic wave, but it is fully determined by the values of $\alpha$ and $$.Comment: 4 pages, 4 figure

Fuel consumption and aftertreatment thermal management synergy in compression ignition engines at variable altitude and ambient temperature

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/10.1177/14680874211035015[EN] New regulations applied to the transportation sector are widening the operation range where the pollutant emissions are evaluated. Besides ambient temperature, the driving altitude is also considered to reduce the gap between regulated and real-life emissions. The altitude effect on the engine performance is usually overcome by acting on the turbocharger control. The traditional strategy assumes to keep (or even to increase) the boost pressure, that is, compressor pressure ratio increase, as the altitude is increased to offset the ambient density reduction, followed by the reduction of the exhaust gas recirculation to reach the targeted engine torque. However, this is done at the expense of an increase on fuel consumption and emissions. This work remarks experimentally the importance of a detailed understanding of the effects of the boost pressure and low-pressure exhaust gas recirculation (LP-EGR) settings when the engine runs low partial loads at different altitudes, accounting for extreme warm and cold ambient temperatures. The experimental results allow defining and justifying clear guidelines for an optimal engine calibration. Opposite to traditional strategies, a proper calibration of the boost pressure and LP-EGR enables reductions in specific fuel consumption along with the gas temperature increase at the exhaust aftertreatment system.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been partially supported by the Ministry of Science and Innovation from the Government of Spain through project PID2020-114289RB-I00. Additionally, the Ph.D. student Barbara Diesel has been funded by a grant from the Government of Generalitat Valenciana with reference ACIF/2018/109.Bermúdez, V.; Serrano, J.; Piqueras, P.; Diesel, B. (2022). Fuel consumption and aftertreatment thermal management synergy in compression ignition engines at variable altitude and ambient temperature. International Journal of Engine Research. 23(11):1954-1966. https://doi.org/10.1177/1468087421103501519541966231

Analysis of heavy-duty turbocharged diesel engine response under cold transient operation with a pre-turbo aftertreatment exhaust manifold configuration

Diesel particulate filters are the most useful technology to reduce particulate matter from the exhaust gas of internal combustion engines. Although these devices have suffered an intense development in terms of the management of filtration and regeneration, the effect of the system location on the engine performance is still a key issue that needs to be properly addressed. The present work is focused on a computational study regarding the effects of a pre-turbo aftertreatment placement under full and partial load transient operation at constant engine speed and low wall temperature along the exhaust line. The aim of the paper is to provide a comprehensive understanding of the engine response to define the guidelines of a control strategy that is able to get the standards of engine driveability during sudden accelerations under restraining thermal transient conditions governed by the aftertreatment thermal inertia. The proposed strategy overcomes the lack of temperature at the inlet of the turbine caused by the thermal transient by means of the boost and EGR control. It leads to a proper management of the power in the exhaust gas for the expansion in the turbine.This work was partially supported by the Universitat Politecnica de Valencia [grant number INNOVA 2011-3182].Bermúdez, V.; Serrano, J.; Piqueras, P.; García Afonso, Ó. (2013). Analysis of heavy-duty turbocharged diesel engine response under cold transient operation with a pre-turbo aftertreatment exhaust manifold configuration. International Journal of Engine Research. 14(4):341-353. https://doi.org/10.1177/1468087412457670S341353144Payri, F., Pastor, J. V., Pastor, J. M., & Juliá, J. E. (2006). Diesel Spray Analysis by Means of Planar Laser-Induced Exciplex Fluorescence. International Journal of Engine Research, 7(1), 77-89. doi:10.1243/146808705x27723Torregrosa, A. J., Broatch, A., Margot, X., Marant, V., & Beauge, Y. (2004). Combustion chamber resonances in direct injection automotive diesel engines: A numerical approach. International Journal of Engine Research, 5(1), 83-91. doi:10.1243/146808704772914264Serrano, J. R., Arnau, F. J., Dolz, V., & Piqueras, P. (2009). Methodology for characterisation and simulation of turbocharged diesel engines combustion during transient operation. Part 1: Data acquisition and post-processing. Applied Thermal Engineering, 29(1), 142-149. doi:10.1016/j.applthermaleng.2008.02.011Serrano, J. R., Climent, H., Guardiola, C., & Piqueras, P. (2009). Methodology for characterisation and simulation of turbocharged diesel engines combustion during transient operation. Part 2: Phenomenological combustion simulation. Applied Thermal Engineering, 29(1), 150-158. doi:10.1016/j.applthermaleng.2008.02.010Rakopoulos, C. D., Dimaratos, A. M., Giakoumis, E. G., & Rakopoulos, D. C. (2009). Evaluation of the effect of engine, load and turbocharger parameters on transient emissions of diesel engine. Energy Conversion and Management, 50(9), 2381-2393. doi:10.1016/j.enconman.2009.05.022Rakopoulos, C. D., Dimaratos, A. M., Giakoumis, E. G., & Rakopoulos, D. C. (2010). Investigating the emissions during acceleration of a turbocharged diesel engine operating with bio-diesel or n-butanol diesel fuel blends. Energy, 35(12), 5173-5184. doi:10.1016/j.energy.2010.07.049Ishikawa, N. (2012). A study on emissions improvement of a diesel engine equipped with a mechanical supercharger. International Journal of Engine Research, 13(2), 99-107. doi:10.1177/1468087411434885Desantes, J. M., Luján, J. M., Pla, B., & Soler, J. A. (2012). On the combination of high-pressure and low-pressure exhaust gas recirculation loops for improved fuel economy and reduced emissions in high-speed direct-injection engines. International Journal of Engine Research, 14(1), 3-11. doi:10.1177/1468087412437623Johnson, T. V. (2009). Review of diesel emissions and control. International Journal of Engine Research, 10(5), 275-285. doi:10.1243/14680874jer04009Tourlonias, P., & Koltsakis, G. (2011). Model-based comparative study of Euro 6 diesel aftertreatment concepts, focusing on fuel consumption. International Journal of Engine Research, 12(3), 238-251. doi:10.1177/1468087411405104Bermúdez, V., Serrano, J. R., Piqueras, P., & García-Afonso, O. (2011). Assessment by means of gas dynamic modelling of a pre-turbo diesel particulate filter configuration in a turbocharged HSDI diesel engine under full-load transient operation. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 225(9), 1134-1155. doi:10.1177/0954407011402278Payri, F., Serrano, J. R., Piqueras, P., & García-Afonso, O. (2011). Performance Analysis of a Turbocharged Heavy Duty Diesel Engine with a Pre-turbo Diesel Particulate Filter Configuration. SAE International Journal of Engines, 4(2), 2559-2575. doi:10.4271/2011-37-0004Galindo, J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2009). Description of a Semi-Independent Time Discretization Methodology for a One-Dimensional Gas Dynamics Model. Journal of Engineering for Gas Turbines and Power, 131(3). doi:10.1115/1.2983015Torregrosa, A. J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2011). A fluid dynamic model for unsteady compressible flow in wall-flow diesel particulate filters. Energy, 36(1), 671-684. doi:10.1016/j.energy.2010.09.047Desantes, J. M., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2012). Derivation of the method of characteristics for the fluid dynamic solution of flow advection along porous wall channels. Applied Mathematical Modelling, 36(7), 3134-3152. doi:10.1016/j.apm.2011.09.090Galindo, J., Serrano, J. R., Piqueras, P., & García-Afonso, Ó. (2012). Heat transfer modelling in honeycomb wall-flow diesel particulate filters. Energy, 43(1), 201-213. doi:10.1016/j.energy.2012.04.04

On the Impact of Particulate Matter Distribution on Pressure Drop of Wall-Flow Particulate Filters

[EN] Wall-flow particulate filters are a required exhaust aftertreatment system to abate particulate matter emissions and meet current and incoming regulations applying worldwide to new generations of diesel and gasoline internal combustion engines. Despite the high filtration efficiency covering the whole range of emitted particle sizes, the porous substrate constitutes a flow restriction especially relevant as particulate matter, both soot and ash, is collected. The dependence of the resulting pressure drop, and hence the fuel consumption penalty, on the particulate matter distribution along the inlet channels is discussed in this paper taking as reference experimental data obtained in water injection tests before the particulate filter. This technique is demonstrated to reduce the particulate filter pressure drop without negative effects on filtration performance. In order to justify these experimental data, the characteristics of the particulate layer are diagnosed applying modeling techniques. Different soot mass distributions along the inlet channels are analyzed combined with porosity change to assess the new properties after water injection. Their influence on the subsequent soot loading process and regeneration is assessed. The results evidence the main mechanisms of the water injection at the filter inlet to reduce pressure drop and boost the interest for control strategies able to force the re-entrainment of most of the particulate matter towards the inlet channels' end.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness through Grant No. TRA2016-79185-R. Additionally, the Ph.D. student Enrique Jose Sanchis has been funded by a grant from Universitat Politecnica de Valencia with the reference FPI-2016-S2-1355.Bermúdez, V.; Serrano, J.; Piqueras, P.; Sanchis-Pacheco, EJ. (2017). On the Impact of Particulate Matter Distribution on Pressure Drop of Wall-Flow Particulate Filters. Applied Sciences. 7(3):1-21. https://doi.org/10.3390/app7030234S12173Johnson, T. V. (2015). Review of Vehicular Emissions Trends. SAE International Journal of Engines, 8(3), 1152-1167. doi:10.4271/2015-01-0993Bermúdez, V., Serrano, J. R., Piqueras, P., & García-Afonso, O. (2011). Assessment by means of gas dynamic modelling of a pre-turbo diesel particulate filter configuration in a turbocharged HSDI diesel engine under full-load transient operation. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 225(9), 1134-1155. doi:10.1177/0954407011402278Subramaniam, M. N., Joergl, V., Keller, P., Weber, O., Toyoshima, T., & Vogt, C. D. (2009). Feasibility Assessment of a Pre-turbo After-Treatment System with a 1D Modeling Approach. SAE Technical Paper Series. doi:10.4271/2009-01-1276Luján, J. M., Bermúdez, V., Piqueras, P., & García-Afonso, Ó. (2015). Experimental assessment of pre-turbo aftertreatment configurations in a single stage turbocharged diesel engine. Part 1: Steady-state operation. Energy, 80, 599-613. doi:10.1016/j.energy.2014.05.048Luján, J. M., Serrano, J. R., Piqueras, P., & García-Afonso, Ó. (2015). Experimental assessment of a pre-turbo aftertreatment configuration in a single stage turbocharged diesel engine. Part 2: Transient operation. Energy, 80, 614-627. doi:10.1016/j.energy.2014.12.017Lee, J. H., Paratore, M. J., & Brown, D. B. (2008). Evaluation of Cu-Based SCR/DPF Technology for Diesel Exhaust Emission Control. SAE International Journal of Fuels and Lubricants, 1(1), 96-101. doi:10.4271/2008-01-0072Watling, T. C., Ravenscroft, M. R., & Avery, G. (2012). Development, validation and application of a model for an SCR catalyst coated diesel particulate filter. Catalysis Today, 188(1), 32-41. doi:10.1016/j.cattod.2012.02.007Marchitti, F., Nova, I., & Tronconi, E. (2016). Experimental study of the interaction between soot combustion and NH3-SCR reactivity over a Cu–Zeolite SDPF catalyst. Catalysis Today, 267, 110-118. doi:10.1016/j.cattod.2016.01.027Konstandopoulos, A. G., & Kostoglou, M. (2014). Analysis of Asymmetric and Variable Cell Geometry Wall-Flow Particulate Filters. SAE International Journal of Fuels and Lubricants, 7(2), 489-495. doi:10.4271/2014-01-1510Bollerhoff, T., Markomanolakis, I., & Koltsakis, G. (2012). Filtration and regeneration modeling for particulate filters with inhomogeneous wall structure. Catalysis Today, 188(1), 24-31. doi:10.1016/j.cattod.2011.12.017Iwata, H., Konstandopoulos, A., Nakamura, K., Ogiso, A., Ogyu, K., Shibata, T., & Ohno, K. (2015). Further Experimental Study of Asymmetric Plugging Layout on DPFs: Effect of Wall Thickness on Pressure Drop and Soot Oxidation. SAE Technical Paper Series. doi:10.4271/2015-01-1016Bermúdez, V., Serrano, J. R., Piqueras, P., & García-Afonso, O. (2015). Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters. Applied Energy, 140, 234-245. doi:10.1016/j.apenergy.2014.12.003Serrano, J. R., Bermudez, V., Piqueras, P., & Angiolini, E. (2015). Application of Pre-DPF Water Injection Technique for Pressure Drop Limitation. SAE Technical Paper Series. doi:10.4271/2015-01-0985Wang, Y., Wong, V., Sappok, A., & Munnis, S. (2013). The Sensitivity of DPF Performance to the Spatial Distribution of Ash Inside DPF Inlet Channels. SAE Technical Paper Series. doi:10.4271/2013-01-1584Sappok, A., Govani, I., Kamp, C., Wang, Y., & Wong, V. (2013). In-Situ Optical Analysis of Ash Formation and Transport in Diesel Particulate Filters During Active and Passive DPF Regeneration Processes. SAE International Journal of Fuels and Lubricants, 6(2), 336-349. doi:10.4271/2013-01-0519Torregrosa, A. J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2011). A fluid dynamic model for unsteady compressible flow in wall-flow diesel particulate filters. Energy, 36(1), 671-684. doi:10.1016/j.energy.2010.09.047CMT-Motores Tèrmicos (Universitat Politècnica de València)www.openwam.orgLax, P. D., & Wendroff, B. (1964). Difference schemes for hyperbolic equations with high order of accuracy. Communications on Pure and Applied Mathematics, 17(3), 381-398. doi:10.1002/cpa.3160170311Serrano, J. R., Arnau, F. J., Piqueras, P., & García-Afonso, O. (2013). Application of the two-step Lax and Wendroff FCT and the CE-SE method to flow transport in wall-flow monoliths. International Journal of Computer Mathematics, 91(1), 71-84. doi:10.1080/00207160.2013.783206Desantes, J. M., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2012). Derivation of the method of characteristics for the fluid dynamic solution of flow advection along porous wall channels. Applied Mathematical Modelling, 36(7), 3134-3152. doi:10.1016/j.apm.2011.09.090Serrano, J. R., Arnau, F. J., Piqueras, P., & García-Afonso, Ó. (2013). Packed bed of spherical particles approach for pressure drop prediction in wall-flow DPFs (diesel particulate filters) under soot loading conditions. Energy, 58, 644-654. doi:10.1016/j.energy.2013.05.051Murtagh, M. J., Sherwood, D. L., & Socha, L. S. (1994). Development of a Diesel Particulate Filter Composition and Its Effect on Thermal Durability and Filtration Performance. SAE Technical Paper Series. doi:10.4271/940235Fino, D., Russo, N., Millo, F., Vezza, D. S., Ferrero, F., & Chianale, A. (2009). New Tool for Experimental Analysis of Diesel Particulate Filter Loading. Topics in Catalysis, 52(13-20), 2083-2087. doi:10.1007/s11244-009-9393-zKonstandopoulos, A. G., & Johnson, J. H. (1989). Wall-Flow Diesel Particulate Filters—Their Pressure Drop and Collection Efficiency. SAE Technical Paper Series. doi:10.4271/890405Lapuerta, M., Ballesteros, R., & Martos, F. J. (2006). A method to determine the fractal dimension of diesel soot agglomerates. Journal of Colloid and Interface Science, 303(1), 149-158. doi:10.1016/j.jcis.2006.07.066Serrano, J. R., Climent, H., Piqueras, P., & Angiolini, E. (2016). Filtration modelling in wall-flow particulate filters of low soot penetration thickness. Energy, 112, 883-898. doi:10.1016/j.energy.2016.06.121Logan, B. E., Jewett, D. G., Arnold, R. G., Bouwer, E. J., & O’Melia, C. R. (1995). Clarification of Clean-Bed Filtration Models. Journal of Environmental Engineering, 121(12), 869-873. doi:10.1061/(asce)0733-9372(1995)121:12(869)Koltsakis, G. C., & Stamatelos, A. M. (1997). Modes of Catalytic Regeneration in Diesel Particulate Filters. Industrial & Engineering Chemistry Research, 36(10), 4155-4165. doi:10.1021/ie970095mBissett, E. J. (1984). Mathematical model of the thermal regeneration of a wall-flow monolith diesel particulate filter. Chemical Engineering Science, 39(7-8), 1233-1244. doi:10.1016/0009-2509(84)85084-8Galindo, J., Serrano, J. R., Piqueras, P., & García-Afonso, Ó. (2012). Heat transfer modelling in honeycomb wall-flow diesel particulate filters. Energy, 43(1), 201-213. doi:10.1016/j.energy.2012.04.044Payri, F., Broatch, A., Serrano, J. R., & Piqueras, P. (2011). Experimental–theoretical methodology for determination of inertial pressure drop distribution and pore structure properties in wall-flow diesel particulate filters (DPFs). Energy, 36(12), 6731-6744. doi:10.1016/j.energy.2011.10.033Konstandopoulos, A. G., Skaperdas, E., & Masoudi, M. (2002). Microstructural Properties of Soot Deposits in Diesel Particulate Traps. SAE Technical Paper Series. doi:10.4271/2002-01-1015Bermúdez, V., Serrano, J. R., Piqueras, P., & Campos, D. (2015). Analysis of the influence of pre-DPF water injection technique on pollutants emission. Energy, 89, 778-792. doi:10.1016/j.energy.2015.05.14

Testing effects of Lorentz invariance violation in the propagation of astroparticles with the Pierre Auger Observatory

Lorentz invariance violation (LIV) is often described by dispersion relations of the form Ei2 = mi2+pi2+δi,n E2+n with delta different based on particle type i, with energy E, momentum p and rest mass m. Kinematics and energy thresholds of interactions are modified once the LIV terms become comparable to the squared masses of the particles involved. Thus, the strongest constraints on the LIV coefficients δi,n tend to come from the highest energies. At sufficiently high energies, photons produced by cosmic ray interactions as they propagate through the Universe could be subluminal and unattenuated over cosmological distances. Cosmic ray interactions can also be modified and lead to detectable fingerprints in the energy spectrum and mass composition observed on Earth. The data collected at the Pierre Auger Observatory are therefore possibly sensitive to both the electromagnetic and hadronic sectors of LIV. In this article, we explore these two sectors by comparing the energy spectrum and the composition of cosmic rays and the upper limits on the photon flux from the Pierre Auger Observatory with simulations including LIV. Constraints on LIV parameters depend strongly on the mass composition of cosmic rays at the highest energies. For the electromagnetic sector, while no constraints can be obtained in the absence of protons beyond 1019 eV, we obtain δγ,0 > -10-21, δγ,1 > -10-40 eV-1 and δγ,2 > -10-58 eV-2 in the case of a subdominant proton component up to 1020 eV. For the hadronic sector, we study the best description of the data as a function of LIV coefficients and we derive constraints in the hadronic sector such as δhad,0 < 10-19, δhad,1 < 10-38 eV-1 and δhad,2 < 10-57 eV-2 at 5σ CL.The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargüe. We are very grateful to the following agencies and organizations for financial support: Argentina — Comisión Nacional de Energía Atómica; Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargüe; NDM Holdings and Valle Las Leñas; in gratitude for their continuing cooperation over land access; Australia — the Australian Research Council; Belgium — Fonds de la Recherche Scientifique (FNRS); Research Foundation Flanders (FWO); Brazil — Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Financiadora de Estudos e Projetos (FINEP); Fundação de Amparo à Pesquisa do Estado de Rio de Janeiro (FAPERJ); São Paulo Research Foundation (FAPESP) Grants No. 2019/10151-2, No. 2010/07359-6 and No. 1999/05404-3; Ministério da Ciência, Tecnologia, Inovações e Comunicações (MCTIC); Czech Republic — Grant No. MSMT CR LTT18004, LM2015038, LM2018102, CZ.02.1.01/0.0/0.0/16_013/0001402, CZ.02.1.01/0.0/0.0/18_046/0016010 and CZ.02.1.01/0.0/0.0/17_049/0008422; France — Centre de Calcul IN2P3/CNRS; Centre National de la Recherche Scientifique (CNRS); Conseil Régional Ile-de-France; Département Physique Nucléaire et Corpusculaire (PNC-IN2P3/CNRS); Département Sciences de l’Univers (SDU-INSU/CNRS); Institut Lagrange de Paris (ILP) Grant No. LABEX ANR-10-LABX-63 within the Investissements d’Avenir Programme Grant No. ANR-11-IDEX-0004-02; Germany — Bundesministerium für Bildung und Forschung (BMBF); Deutsche Forschungsgemeinschaft (DFG); Finanzministerium Baden-Württemberg; Helmholtz Alliance for Astroparticle Physics (HAP); Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF); Ministerium für Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen; Ministerium für Wissenschaft, Forschung und Kunst des Landes Baden-Württemberg; Italy — Istituto Nazionale di Fisica Nucleare (INFN); Istituto Nazionale di Astrofisica (INAF); Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR); CETEMPS Center of Excellence; Ministero degli Affari Esteri (MAE); México — Consejo Nacional de Ciencia y Tecnología (CONACYT) No. 167733; Universidad Nacional Autónoma de México (UNAM); PAPIIT DGAPA-UNAM; The Netherlands — Ministry of Education, Culture and Science; Netherlands Organisation for Scientific Research (NWO); Dutch national e-infrastructure with the support of SURF Cooperative; Poland — Ministry of Education and Science, grant No. DIR/WK/2018/11; National Science Centre, Grants No. 2016/22/M/ST9/00198, 2016/23/B/ST9/01635, and 2020/39/B/ST9/01398; Portugal — Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundação para a Ciência e a Tecnologia (COMPETE); Romania — Ministry of Research, Innovation and Digitization, CNCS/CCCDI — UEFISCDI, projects PN19150201/16N/2019, PN1906010, TE128 and PED289, within PNCDI III; Slovenia — Slovenian Research Agency, grants P1-0031, P1-0385, I0-0033, N1-0111; Spain — Ministerio de Economía, Industria y Competitividad (FPA2017-85114-P and PID2019-104676GB-C32), Xunta de Galicia (ED431C 2017/07), Junta de Andalucía (SOMM17/6104/UGR, P18-FR-4314) Feder Funds, RENATA Red Nacional Temática de Astropartículas (FPA2015-68783-REDT) and María de Maeztu Unit of Excellence (MDM-2016-0692); U.S.A. — Department of Energy, Contracts No. DE-AC02-07CH11359, No. DE-FR02-04ER41300, No. DE-FG02-99ER41107 and No. DE-SC0011689; National Science Foundation, Grant No. 0450696; The Grainger Foundation; Marie Curie-IRSES/EPLANET; European Particle Physics Latin American Network; and UNESCO.S

EL RASTRO DE TU RAZÓN EN LA NIEVE: leyendo un texto literario con Martha Nussbaum

—Merde! Allez-vous-en! Exclama impaciente el guardia del lado francés en laciudad fronteriza de Hendaya. Con su maestría característica, García Márquez hasabido escoger la expresión que en un momento álgido del relato simboliza laincapacidad de simpatizar. El escenario tal cual desfila ante los ojos del lectordificulta en extremo la comunicación: “... los guardias de Hendaya estabansentados a la mesa en mangas de camisa, jugando barajas mientras comían panmojado en tazones de vino dentro de una garita de cristal cálida y bienalumbrada...” (pág. 202), mientras Billy Sánchez y Nena Daconte tratan dehacerse entender en medio del fragor helado de una tormenta de nieve. Conocidaes de sobra para cualquier viajero la impaciencia gala frente al extranjero incauto,por lo cual no nos extraña que la escena se desenvuelva tal cual está narrada porel autor. Lo que sí nos sorprende es la ‘maleabilidad emocional’ del mismo guardiaquien minutos antes con la boca llena de pan ha vociferado que no es asunto suyodecirles dónde diablos encontrar una farmacia, pero cambia de repente su actitudhacia la joven que se chupa el dedo herido “envuelta en el destello de los bisonesnaturales” (ibídem), y al instante también su humor, porque “debió confundirla conuna aparición mágica en aquella noche de espantos” (ibídem). Aquí la experienciaestética, aún en un escenario inadecuado, crea el vínculo que hace posible evadirel estrecho círculo que determina y fija una conducta intolerante e intransigenteinscrita en una racionalidad que para el caso está incubada en el otorgamiento deautoridad por un lado, y por el otro, en la apatía antipática de la rutina

Thermoelectric simulation of electric machines with permanent magnets

The objective of this work is to describe some numerical tools developed to perform the thermoelectric simulation of electric machines. From the electromagnetic point of view, we will focus on the computation of nonlinear 2D transient magnetic fields where the data concerning the electric current sources involve potential drops excitations. From the thermal point of view, once the electromagnetic losses are known, we will show an application of a Galerkin lumped parameter method (GLPM) to simulate the thermal behavior of an electric motor. The proposed methods are applied to the simulation of a permanent magnet synchronous electric motor

Scattering at the Anderson transition: Power--law banded random matrix model

We analyze the scattering properties of a periodic one-dimensional system at criticality represented by the so-called power-law banded random matrix model at the metal insulator transition. We focus on the scaling of Wigner delay times $\tau$ and resonance widths $\Gamma$. We found that the typical values of $\tau$ and $\Gamma$ (calculated as the geometric mean) scale with the system size $L$ as $\tau^{\tiny typ}\propto L^{D_1}$ and $\Gamma^{\tiny typ} \propto L^{-(2-D_2)}$, where $D_1$ is the information dimension and $D_2$ is the correlation dimension of eigenfunctions of the corresponding closed system.Comment: 6 pages, 8 figure