Theoretical study of light and sound interaction in phoxonic crystal structures

En esta tesis se realiza un estudio teórico de la interacción luz-sonido en estructuras foxonicas, con las cuales es posible el control de la luz y el sonido a la misma vez. Esta interacción en dichas estructuras se estudia, tanto desde un punto de vista macroscópico (diseño de estructuras para el confinamiento y guiado de ondas electromagnéticas y elásticas) como microscópico (estudio de la interacción fotón-fonón en microcavidades y desarrollo teórico de modelos cuánticos para la comprensión de dicha interacción).Escalante Fernández, JM. (2013). Theoretical study of light and sound interaction in phoxonic crystal structures [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/33754TESI

Theoretical study about the gain in indirect bandgap semiconductor optical cavities

[EN] Indirect bandgap semiconductors such as silicon are not efficient light emitters because a phonon with a high momentum is required to transfer an electron from the conduction to the valence band. In a recent study (M.J. Chen et al., 2006) [6] an analytical expression of the optical gain in bulk indirect bandgap semiconductors was obtained. The main conclusion was that the free-carrier absorption was much higher than the optical gain at ambient temperature, which prevents lasing. In this work, we consider the case in which the semiconductor material is engineered to form an optical cavity characterized by a certain Purcell factor. We conclude that although the optical gain is increased, losses due to free carriers increase in the same way so lasing is also prevented even when creating a high-Q optical cavity. © 2012 Elsevier B.V. All rights reserved.This research has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement number 233883 (TAILPHOX). The authors wish to thank M.J. Chen for his useful comments.Escalante Fernández, JM.; Martínez Abietar, AJ. (2012). Theoretical study about the gain in indirect bandgap semiconductor optical cavities. Physica B: Condensed Matter. 407(12):2044-2049. https://doi.org/10.1016/j.physb.2012.02.002204420494071

Factores socioeducativos que inciden en el sistema educativo a nivel nacional en la continuidad de la formación académica de los estudiantes en educación básica, media y superior, durante el año 2018

La investigación responde a los factores socioeducativos que inciden en el sistema educativo a nivel nacional en la continuidad de la formación académica de los estudiantes en educación básica, media y superior. Uno de esos factores en el cual se ha direccionado la investigación, es la actualización docente y como ésta incide en el proceso de enseñanza aprendizaje que reciben los estudiantes de las universidades privadas y públicas de la zona central de El Salvador

Armeria castrovalnerana sp. nov., un nuevo taxon de Armeria gr. alpina en el macizo del Castro Valnera (Cordillera Cantábrica, Burgos)

Se describe una nueva especie del género Armeria (Plumbaginaceae) recolectada en el macizo del Castro Valnera (extremo oriental de la Cordillera Cantábrica). Se ha detectado una única población con no más de 190 individuos, en condiciones de extremo aislamiento geográfico y ecológico. La evolución reticular característica del género, que con frecuencia llega a producir microespecies de área muy reducida, aconseja que se tomen medidas de protección que aseguren su supervivencia

Whole Core Pin-by-Pin Coupled Neutronic-Thermal-hydraulic Steady state and Transient Calculations using COBAYA3 code

Nowadays, coupled 3D neutron-kinetics and thermal-hydraulic core calculations are performed by applying a radial average channel approach using a meshing of one quarter of assembly in the best case. This approach does not take into account the subchannels effects due to the averaging of the physical fields and the loose of heterogeneity in the thermal-hydraulic modelization. Therefore the models do not have enough resolution to predict those subchannels effects which are important for the fuel design safety margins, because it is in the local scale, where we can search the hottest pellet or the maximum heat flux. The UPM advanced multi-scale neutron-kinetics and thermal-hydraulics methodologies being implemented in COBAYA3 include domain decomposition by alternate core dissections for the local 3D fine-mesh scale problems (pin cells/subchannels) and an analytical nodal diffusion solver for the coarse mesh scale coupled with the thermal-hydraulic using a modelization of one channel per assembly or per quarter of assembly. In this work, we address the domain decomposition by the alternate core dissections methodology applied to solve coupled 3D neutronic/thermal-hydraulic (N-TH) problems at the fine-mesh scale. The N-TH coupling at the cell-subchannel scale allows the treatment of the effects of the detailed TH feedbacks on cross-sections, thus resulting in better estimates of the local safety margins at the pin level

Estudio del comportamiento de las propiedades organolépticas y de la Edad Química del vino de flor de Jamaica joven y de crianza

El presente trabajo trata del desarrollo de procesos de producción del vino de flor de Jamaica, en la búsqueda de variables que alteran las propiedades organolépticas y de la edad química, en la obtención de vinos de calidad y que permita tener una idea inicial en cuanto al proceso de elaboración y maduración, Propone una alternativa de utilización e incremento del valor agregado al vino de flor de Jamaica y a la utilización de madera autóctonas para su maduración

De Castella vetula : (hojas de un libro de viajes)

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Effect of loss on the dispersion relation of photonic and phononic crystals

[EN] A theoretical analysis is made of the transformation of the dispersion relation of waves in artificial crystals under the influence of loss, including the case of photonic and phononic crystals. Considering a general dispersion relation in implicit form, an analytic procedure is derived to obtain the transformed dispersion relation. It is shown that the dispersion relation is generally shifted in the complex (k,ω) plane, with k the wave number and ω the angular frequency. The value of the shift is obtained explicitly as a function of the perturbation of material constants accounting for loss. The method is shown to predict correctly the transformation of the complex band structure k(ω). Several models of the dispersion relation near a symmetry point of the Brillouin zone are analyzed. A lower bound for the group velocity, related to the local shape of the band around symmetry points, is derived for each caseFinancial support from the European Community's Seventh Framework program (FP7/2007-2013) under Grant Agreement No. 233883 (TAILPHOX) is gratefully acknowledged. V. L. acknowledges the support of the Labex ACTION program (Contract No. ANR-11-LABX-01-01).Laude, V.; Escalante Fernández, JM.; Martínez Abietar, AJ. (2013). Effect of loss on the dispersion relation of photonic and phononic crystals. Physical Review B. 88:2243021-2243028. https://doi.org/10.1103/PhysRevB.88.224302S2243021224302888Kushwaha, M. S., Halevi, P., Dobrzynski, L., & Djafari-Rouhani, B. (1993). Acoustic band structure of periodic elastic composites. Physical Review Letters, 71(13), 2022-2025. doi:10.1103/physrevlett.71.2022Pennec, Y., Vasseur, J. O., Djafari-Rouhani, B., Dobrzyński, L., & Deymier, P. A. (2010). Two-dimensional phononic crystals: Examples and applications. Surface Science Reports, 65(8), 229-291. doi:10.1016/j.surfrep.2010.08.002Maldovan, M., & Thomas, E. L. (2006). Simultaneous localization of photons and phonons in two-dimensional periodic structures. Applied Physics Letters, 88(25), 251907. doi:10.1063/1.2216885Sadat-Saleh, S., Benchabane, S., Baida, F. I., Bernal, M.-P., & Laude, V. (2009). Tailoring simultaneous photonic and phononic band gaps. Journal of Applied Physics, 106(7), 074912. doi:10.1063/1.3243276Baba, T. (2008). Slow light in photonic crystals. Nature Photonics, 2(8), 465-473. doi:10.1038/nphoton.2008.146Thévenaz, L. (2008). Slow and fast light in optical fibres. Nature Photonics, 2(8), 474-481. doi:10.1038/nphoton.2008.147Laude, V., Beugnot, J.-C., Benchabane, S., Pennec, Y., Djafari-Rouhani, B., Papanikolaou, N., … Martinez, A. (2011). Simultaneous guidance of slow photons and slow acoustic phonons in silicon phoxonic crystal slabs. Optics Express, 19(10), 9690. doi:10.1364/oe.19.009690Vlasov, Y. A., O’Boyle, M., Hamann, H. F., & McNab, S. J. (2005). Active control of slow light on a chip with photonic crystal waveguides. Nature, 438(7064), 65-69. doi:10.1038/nature04210Hughes, S., Ramunno, L., Young, J. F., & Sipe, J. E. (2005). Extrinsic Optical Scattering Loss in Photonic Crystal Waveguides: Role of Fabrication Disorder and Photon Group Velocity. Physical Review Letters, 94(3). doi:10.1103/physrevlett.94.033903O’Faolain, L., White, T. P., O’Brien, D., Yuan, X., Settle, M. D., & Krauss, T. F. (2007). Dependence of extrinsic loss on group velocity in photonic crystal waveguides. Optics Express, 15(20), 13129. doi:10.1364/oe.15.013129Pedersen, J. G., Xiao, S., & Mortensen, N. A. (2008). Limits of slow light in photonic crystals. Physical Review B, 78(15). doi:10.1103/physrevb.78.153101Hussein, M. I. (2009). Theory of damped Bloch waves in elastic media. Physical Review B, 80(21). doi:10.1103/physrevb.80.212301Moiseyenko, R. P., & Laude, V. (2011). Material loss influence on the complex band structure and group velocity in phononic crystals. Physical Review B, 83(6). doi:10.1103/physrevb.83.064301Figotin, A., & Vitebskiy, I. (2006). Slow light in photonic crystals. Waves in Random and Complex Media, 16(3), 293-382. doi:10.1080/17455030600836507Thurston, R. N. (1977). Direct Calculation of the Group Velocity. IEEE Transactions on Sonics and Ultrasonics, 24(2), 109-110. doi:10.1109/t-su.1977.30920Hsue, Y.-C., Freeman, A. J., & Gu, B.-Y. (2005). Extended plane-wave expansion method in three-dimensional anisotropic photonic crystals. Physical Review B, 72(19). doi:10.1103/physrevb.72.195118Stefanou, N., Karathanos, V., & Modinos, A. (1992). Scattering of electromagnetic waves by periodic structures. Journal of Physics: Condensed Matter, 4(36), 7389-7400. doi:10.1088/0953-8984/4/36/013Laude, V., Achaoui, Y., Benchabane, S., & Khelif, A. (2009). Evanescent Bloch waves and the complex band structure of phononic crystals. Physical Review B, 80(9). doi:10.1103/physrevb.80.092301Psarobas, I. E., Stefanou, N., & Modinos, A. (2000). Scattering of elastic waves by periodic arrays of spherical bodies. Physical Review B, 62(1), 278-291. doi:10.1103/physrevb.62.278Laude, V., Moiseyenko, R. P., Benchabane, S., & Declercq, N. F. (2011). Bloch wave deafness and modal conversion at a phononic crystal boundary. AIP Advances, 1(4), 041402. doi:10.1063/1.3675828Yang, S., Page, J. H., Liu, Z., Cowan, M. L., Chan, C. T., & Sheng, P. (2002). Ultrasound Tunneling through 3D Phononic Crystals. Physical Review Letters, 88(10). doi:10.1103/physrevlett.88.104301Davoyan, A. R., Liu, W., Miroshnichenko, A. E., Shadrivov, I. V., Kivshar, Y. S., & Bozhevolnyi, S. I. (2011). Mode transformation in waveguiding plasmonic structures. Photonics and Nanostructures - Fundamentals and Applications, 9(3), 207-212. doi:10.1016/j.photonics.2011.01.00

Design of single-mode waveguides for enhanced light-sound interaction in honeycomb-lattice silicon slabs

We present the design of two waveguides (ladder and slot-ladder waveguides) implemented in a silicon honeycomb photonic-phononic crystal slab, which can support slow electromagnetic and elastic guided modes simultaneously. Interestingly, the photonic bandgap extends along the first Brillouin zone; so with an appropriate design, we can suppress propagation losses that arise coupling to radiative modes. From the phononic point of view, we explain the slow elastic wave effect by considering the waveguide as a chain of coupled acoustic resonators (coupled resonant acoustic waveguide), which provides the mechanism for slow elastic wave propagation. The ladder waveguide moreover supports guided phononic modes outside the phononic bandgap, similar to photonic slab modes, resulting in highly confined phononic modes propagating with low losses. Such waveguides could find important applications to the observation of optomechanical and electrostriction effects, as well as to enhanced stimulated Brillouin scattering and other opto-acoustical effects in nanoscale silicon structures. We also suggest that they can be the basis for a "perfect" photonic-phononic cavity in which damping by coupling to the surroundings is completely forbidden.Financial support from the multidisciplinary project of UPV, PAID-05-12 (CE 20130141).Escalante Fernández, JM.; Martínez Abietar, AJ.; Laude, V. (2014). Design of single-mode waveguides for enhanced light-sound interaction in honeycomb-lattice silicon slabs. Journal of Applied Physics. 115(6):64302-64307. https://doi.org/10.1063/1.4864661S64302643071156Maldovan, M., & Thomas, E. L. (2006). Simultaneous localization of photons and phonons in two-dimensional periodic structures. Applied Physics Letters, 88(25), 251907. doi:10.1063/1.2216885Maldovan, M., & Thomas, E. L. (2006). Simultaneous complete elastic and electromagnetic band gaps in periodic structures. Applied Physics B, 83(4), 595-600. doi:10.1007/s00340-006-2241-ySadat-Saleh, S., Benchabane, S., Baida, F. I., Bernal, M.-P., & Laude, V. (2009). Tailoring simultaneous photonic and phononic band gaps. Journal of Applied Physics, 106(7), 074912. doi:10.1063/1.3243276Mohammadi, S., Eftekhar, A. A., Khelif, A., & Adibi, A. (2010). Simultaneous two-dimensional phononic and photonic band gaps in opto-mechanical crystal slabs. Optics Express, 18(9), 9164. doi:10.1364/oe.18.009164Eichenfield, M., Chan, J., Camacho, R. M., Vahala, K. J., & Painter, O. (2009). Optomechanical crystals. Nature, 462(7269), 78-82. doi:10.1038/nature08524Laude, V., Beugnot, J.-C., Benchabane, S., Pennec, Y., Djafari-Rouhani, B., Papanikolaou, N., … Martinez, A. (2011). Simultaneous guidance of slow photons and slow acoustic phonons in silicon phoxonic crystal slabs. Optics Express, 19(10), 9690. doi:10.1364/oe.19.009690Pennec, Y., Rouhani, B. D., El Boudouti, E. H., Li, C., El Hassouani, Y., Vasseur, J. O., … Martinez, A. (2010). Simultaneous existence of phononic and photonic band gaps in periodic crystal slabs. Optics Express, 18(13), 14301. doi:10.1364/oe.18.014301Papanikolaou, N., Psarobas, I. E., & Stefanou, N. (2010). Absolute spectral gaps for infrared light and hypersound in three-dimensional metallodielectric phoxonic crystals. Applied Physics Letters, 96(23), 231917. doi:10.1063/1.3453448SoljaČiĆ, M., & Joannopoulos, J. D. (2004). Enhancement of nonlinear effects using photonic crystals. Nature Materials, 3(4), 211-219. doi:10.1038/nmat1097Khelif, A., Mohammadi, S., Eftekhar, A. A., Adibi, A., & Aoubiza, B. (2010). Acoustic confinement and waveguiding with a line-defect structure in phononic crystal slabs. Journal of Applied Physics, 108(8), 084515. doi:10.1063/1.3500226Escalante, J. M., Martínez, A., & Laude, V. (2013). Dispersion relation of coupled-resonator acoustic waveguides formed by defect cavities in a phononic crystal. Journal of Physics D: Applied Physics, 46(47), 475301. doi:10.1088/0022-3727/46/47/475301Adibi, A., Yong Xu, Lee, R. K., Yariv, A., & Scherer, A. (2000). Properties of the slab modes in photonic crystal optical waveguides. Journal of Lightwave Technology, 18(11), 1554-1564. doi:10.1109/50.896217Adibi, A., Xu, Y., Lee, R. K., Yariv, A., & Scherer, A. (2001). Guiding mechanisms in dielectric-core photonic-crystal optical waveguides. Physical Review B, 64(3). doi:10.1103/physrevb.64.033308Krautkrämer, J., & Krautkrämer, H. (1990). Ultrasonic Testing of Materials. doi:10.1007/978-3-662-10680-8Puerto, D., Griol, A., Escalante, J. M., Pennec, Y., Djafari-Rouhani, B., Beugnot, J., … Martinez, A. (2012). Honeycomb Photonic Crystal Waveguides in a Suspended Silicon Slab. IEEE Photonics Technology Letters, 24(22), 2056-2059. doi:10.1109/lpt.2012.2219516Song, B.-S., Noda, S., Asano, T., & Akahane, Y. (2005). Ultra-high-Q photonic double-heterostructure nanocavity. Nature Materials, 4(3), 207-210. doi:10.1038/nmat1320Safavi-Naeini, A. H., Alegre, T. P. M., Winger, M., & Painter, O. (2010). Optomechanics in an ultrahigh-Q two-dimensional photonic crystal cavity. Applied Physics Letters, 97(18), 181106. doi:10.1063/1.3507288Chan, J., Safavi-Naeini, A. H., Hill, J. T., Meenehan, S., & Painter, O. (2012). Optimized optomechanical crystal cavity with acoustic radiation shield. Applied Physics Letters, 101(8), 081115. doi:10.1063/1.4747726Shin, H., Qiu, W., Jarecki, R., Cox, J. A., Olsson, R. H., Starbuck, A., … Rakich, P. T. (2013). Tailorable stimulated Brillouin scattering in nanoscale silicon waveguides. Nature Communications, 4(1). doi:10.1038/ncomms2943Chan, J., Alegre, T. P. M., Safavi-Naeini, A. H., Hill, J. T., Krause, A., Gröblacher, S., … Painter, O. (2011). Laser cooling of a nanomechanical oscillator into its quantum ground state. Nature, 478(7367), 89-92. doi:10.1038/nature1046

Increments in cytokines and matrix metalloproteinases in skeletal muscle after injection of tissue-damaging toxins from the venom of the snake Bothrops asper.

Envenomations by the snake Bothrops asper are characterized by prominent local tissue damage (i.e. myonecrosis), blistering, hemorrhage and edema. Various phospholipases A2 and metalloproteinases that induce local pathological alterations have been purified from this venom. Since these toxins induce a conspicuous inflammatory response, it has been hypothesized that inflammatory mediators may contribute to the local pathological alterations described. This study evaluated the local production of cytokines and matrix metalloproteinases (MMPs) as a consequence of intramuscular injections of an Asp-49 myotoxic phospholipase A2 (myotoxin III (MT-III)) and a P-I type hemorrhagic metalloproteinase (BaP1) isolated from B. asper venom. Both enzymes induced prominent tissue alterations and conspicuous increments in interleukin (IL)-1beta, IL-6 and a number of MMPs, especially gelatinase MMP-9, rapidly after injection. In contrast, no increments in tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma were detected. In agreement, MT-III and BaP1 did not induce the synthesis of TNF-alpha by resident peritoneal macrophages in vitro. Despite the conspicuous expression of latent forms of MMPs in muscle, evidenced by zymography, there were no increments in activated MMP-2 and only a small increase in activated MMP-9, as detected by a functional enzymatic assay. This suggests that MMP activity was regulated by a highly controlled activation of latent forms and, probably, by a concomitant synthesis of MMP inhibitors. Since no hemorrhage nor dermonecrosis were observed after injection of MT-III, despite a prominent increase in MMP expression, and since inflammatory exudate did not enhance hemorrhage induced by BaP1, it is suggested that endogenous MMPs released in the tissue are not responsible for the dermonecrosis and hemorrhage characteristic of B. asper envenomation. Moreover, pretreatment of mice with the peptidomimetic MMP inhibitor batimastat did not reduce myotoxic nor edema-forming activities of MT-III, suggesting that MMPs do not play a prominent role in the pathogenesis of these effects in this experimental model. It is concluded that MT-III and BaP1 induce a local inflammatory response associated with the synthesis of IL-1beta, IL-6 and MMPs. MMPs do not seem to play a prominent role in the acute local pathological alterations induced by these toxins in this experimental model