2,453 research outputs found
Supplemental Material to Laboratory study of rate coefficients for H2:H2 inelastic collisions between 295 and 20 K
No full textThis data set contains the Supplemental Material to the paper "Laboratory study of rate coefficients for H2:H2 inelastic collisions between 295 and 20 K" by S. Montero, G. Tejeda, and J.M. Fernandez, to be published in Astrophysical Journal Supplement Series (2019).This data set contains several topics related with the structure and properties of the Master Equation (MEQ) employed in the main article, owing to its potential interest for the detailed understanding of thermal non-equilibrium in H2 media. These topics include:
1) The general structure of the MEQ.
2) The importance of "up-down" inelastic collision processes for the correct interpretation of H2 rarefi
ed media.
3) The influence of the medium onto the e
ficiency of the inelastic collision processes.
4) The detailed structure of the MEQ, in the form of three Tables containing all the experimental data on the local gas-dynamic variables and on the collision rates at three selected points of the supersonic jet.Spanish Ministerio de Ciencia e Innovación (MICINN) and Spanish Ministerio de Economia y Competitividad (MINECO), grants CONSOLIDER-ASTROMOL CSD2009-0038, FIS2010-22064-C01, FIS2013-48275-C2-2-P, and FIS2017-84391-C2-1-P.N
Bayesian Modeling of Human-AI Complementarity
No full textImageNet-16H dataset and code for the Bayesian Combination Model described in the paper: Steyvers, M., Tejeda, H., Kerrigan, G., & Smyth, P. (2022). Bayesian Modeling of Human-AI Complementarity. Proceedings of the National Academy of Sciences, 119(11), e2111547119, 1-7
Bayesian Modeling of Human-AI Complementarity
No full textImageNet-16H dataset and code for the Bayesian Combination Model described in the paper: Steyvers, M., Tejeda, H., Kerrigan, G., & Smyth, P. (2022). Bayesian Modeling of Human-AI Complementarity. Proceedings of the National Academy of Sciences, 119(11), e2111547119, 1-7
Deformation monitoring in Zafarraya fault and Sierra Tejeda antiform (Betic cordillera, Spain) using satellite radar interferometry
No full textThe Betic-Rif cordilleras are build-up in the western Mediterranean by the deformations related to the Eurasian-African plate boundary. The recent NW-SE convergence produces the simultaneous development of large folds and faults in the central part of the Internal Zones of the Betic Cordilleras, which continues active up to Present. The uplift of the mountain ranges is mainly related to the development of folds in this regional compressive setting. Sierra Tejeda constitutes a relief related to the development of a complex shaped recent antiform that is located near the coast line. At the northern limb of Sierra Tejeda is located the Zafarraya fault, a high-angle northwards dipping normal fault. Understanding the tectonic of the Zafarraya fault is crucial since one of the most destructive earthquakes (25th December 1884) on the Iberian Peninsula occurred along this fault (magnitude of 6.7). This paper investigates the applicability of satellite radar interferometry using ERS-1/2 SAR and Envisat ASAR datasets to help to constraint the geological hazard in this part of the Betic Cordillera
Author Correction: Retinoic acid signaling is critical during the totipotency window in early mammalian development.
No full textIn the version of this article initially published, the surname of author Mayra L. Ruiz Tejada Segura was misspelled as Ruiz Tejeda Segura. The error has been corrected in the online version of the article
El archivo en la autonovela familiar. El caso de Mi abuelo y el dictador de César Tejeda
Full text linkThe aim of this article is to examine the function of the archive in family autonovels and, in particular, in Mi abuelo y el dictador (2017) by the Mexican author César Tejeda. First of all, the characteristics of this phenomenon will be defined and, subsequently, will be applied to Tejeda's autonovel through a textual and paratextual analysis. Afterwards, the specific function of the archive in autonovels will be explained at length and, finally, the archives (letters, personal interviews, historical documents and places of memory) that are integrated into the book will be detailed. The result of this paper is to emphasize that the archive, which is the gap in itself (Didi-Huberman), turns the autobiographical family story into a truthful and, moreover, political manifestation.El objetivo de este artículo es estudiar la función del archivo en las autonovelas familiares y, en particular, en Mi abuelo y el dictador (2017) del mexicano César Tejeda. Primero se definirán las características de este fenómeno, que posteriormente se aplicarán a la autonovela de Tejeda a través del análisis textual y paratextual del mismo. A continuación, se estudiará en más profundidad la función específica del archivo en las autonovelas y, finalmente, se detallarán los archivos (cartas, entrevistas personales, documentos históricos y lugares de memoria) que se encuentran integrados en el libro. El resultado de este trabajo es subrayar que el archivo, que no es más que su hueco (Didi-Huberman), convierte el relato autobiográfico familiar en una manifestación veraz y, además, política
Abrazo rápido en neonatos críticos con hipotermia terapéutica
Full text linkFil: Tejeda, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Enfermería; Argentina.Debido la importancia del cuidado en pacientes críticos y las falencias en la unificación de criterios para su manejo seguro urge la necesidad en la Unidad de Terapia Intensiva Neonatal de la Maternidad Provincial implementar un protocolo para poder tener en cuenta la atención básica durante la terapéutica neuroprotectora como la hipotermia. Gracias a la creación del Dr. Vincent en el año 2005 el método Fast Hug “abrazo rápido” que describe cada sigla en inglés como (F -alimentación, A -analgesia ,S -sedación ,T -tromboflebitis, H -elevación de la cabecera, U -ulcera y G -glucosa) se puede tener en cuenta los procedimientos fundamentales para la atención directa del neonato sin correr riesgo de olvidar u omitir la asistencia principal ni caer en el error de producir daño secundario. Esta técnica ha demostrado gracias a investigaciones científicas que facilita la tarea en el momento de intervención y reduce el riesgo de morbimortalidad ,es fácil de utilizar puede adaptarse a todo tipo de paciente y puede llevarla a cabo cualquier integrante del equipo de salud. Sirve como instrumento de guía o repaso la idea de Vincent es a través de esta herramienta poder contener al paciente en el momento más crítico de su vida con la diligencia que permita su recuperación exitosa. La finalidad de este protocolo es poder darle un abrazo rápido al neonato desde su primera hora de vida y favorecer su recuperación rodeándolo y protegiéndolo con los cuidados esenciales de Enfermería. Para alcanzar este propósito se realizó una búsqueda exhaustiva en la base de datos electrónicas científicas nacionales e internacionales.Fil: Tejeda, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Enfermería; Argentina
Diagnostics of D2, D2+H2 and D2+He supersonic jets by Raman spectroscopy
No full text31st International Symposium on Rarefied Gas Dynamics. 23-27 July, Glasgow, UK (2018). .-/www.jwfl.ac.uk/event_detail.cfm?pid=07C7020B-AC36-4F5B-BA23-1BE3EC1C67D9An experimental study of supersonic jets of pure D2, and of its mixtures with H2 and He, is presented.
Supersonic flows of hydrogen isotopes (H2 and D2) are difficult to model by using either continuous gas dynamics, even with empirical ad hoc ¿molecular¿ corrections, or numerical Monte Carlo simulations. This is due to [1]:
1. their low molecular mass and moment of inertia (large energy gap between rotational levels) leads to the occurrence of non-negligible quantum effects, and a marked decoupling between translational and rotational motions.
2. normal hydrogen isotopes behave like a mixture of two non-interconvertible species (ortho and para), due to nuclear spin statistics.
Raman (inelastic light) scattering is a non-intrusive and powerful diagnostics technique for molecular gas flows [2]: it is able to map, with a high spatial resolution (few microns), number densities and rotational populations (temperatures) of molecular gases, even at the high gradients occurring in shock waves [3-5].
In this work, a number of supersonic microjets of pure D2, and mixed with H2 and He with different mixing ratios, have been quantitatively characterized in terms of number densities n(z) and rotational populations PJ(z) along the jet axis (z) by means of vibrational Raman spectra with rotational resolution.
The circular nozzle had an exit diameter of 350 um, stagnation pressure ranged from 0.25 to 3 bar, and stagnation temperature from 293 to 363 K.
Rotational populations PJ were obtained from the relative intensities of the rotational Q(J) lines of the vibrational Q branches at ~4150 cm¿1 (H2) and ~2990 cm¿1 (D2). Number densities n(z) were obtained by comparing the integrated intensity of each full Q branch with that from static samples at known densities.
Translational temperatures can be obtained from number densities and rotational populations by conservation of mass, momentum, and energy along the jet streamlines [6].
Special attention was paid to an accurate sensitivity calibration of the CCD detector, and to the high gradients present in the flow field close to the nozzle exit.
Experimental data, like those gathered in the present work, are expected to be of great value to improve our understanding of such flows at molecular scale.
REFERENCES
[1] S. Montero, J. Pérez-Ríos, Journal of Chemical Physics 141, 114301 (2014)
[2] S. Montero, B. Maté, G. Tejeda, J.M. Fernández, A. Ramos, in Atomic and Molecular Beams. The State of the Art 2000, Springer, Berlin, 2001, pp. 295-306
[3] A. Ramos, B. Maté, G. Tejeda, J.M. Fernández, S. Montero, Physical Review E 62, 4940 (2000)
[4] I. Graur, T. Elizarova, A. Ramos, G. Tejeda, J.M. Fernández, S. Montero, Journal of Fluid Mechanics 504, 239 (2004)
[5] A. Ramos, G. Tejeda, J.M. Fernández, S. Montero, Journal of Physical Chemistry A 114, 7761 (2010)
[6] B. Maté, G. Tejeda, S. Montero, Journal of Chemical Physics 108, 2676 (1998
Collisional processes of H2O+He Supersonic Jets by Raman Spectroscopy
No full textSupersonic jets of pure gases and gas mixtures are relevant for different areas of physics, chemistry, and engineering [1]. The properties of these systems can differ markedly from those of a gas at thermodynamic equilibrium, since they are conditioned by the collisional dynamics. In this work we report the diagnostic of several H2O + He supersonic jets, with H2O mole fractions from 1.4% to 33%, particularly their fluid dynamic properties. With H2O partial pressures around 12 mbar, all these jets were checked to be free from H2O condensation, a must for the quantitative analysis of the collisional kinetics. The jets have been probed by Raman spectroscopy, a non-intrusive technique with a spatial resolution of a few microns. The primary experimental data obtained are number densities and rotational populations along the flow lines. It is found that the distribution function of the lowest rotational energy levels very nearly obeys a Boltzmann distribution for all our stagnation conditions. This enables accurate determination of rotational temperatures by means of the Raman spectra of Q branch of the symmetric stretching mode (¿1 ~ 3657 cm¿1) and the simulation of its profile using literature reference data [2]. Translational temperatures (Tt) have been obtained from number densities and rotational temperatures by conservation of mass, momentum, and enthalpy along the jet [3]. Employing a Kinetic Master Equation that describes the time evolution of the rotational populations we have determined the average rate coefficients, both for H2O:He and H2O:H2O collisions, for the 6 lowest of ortho-H2O between Tt= 40 and 100K. Our results for H2O:He inelastic collisions will be compared with calculated [4,5] state-to-state rate coefficients. References [1] Tejeda, G.; Maté, B.; Fernández-Sánchez, J.M. and Montero, S. Phys. Rev. Lett., 76, 34, (1996). [2] Avila, G.; Fernández, J. M.; Tejeda, G. and Montero, S. J. Mol. Spect., 228 (1), 38, (2004). [3] B. Maté, G. Tejeda, and S. Montero, J. Chem. Phys. 108, 2676 (1998). [4] S. Green, S. Maluendes, and A. D. McLean, Astrophys. J. Supp. Ser. 85, 181 (1993). [5] E. Carmona-Novillo, M. I. Hernández, J. Campos-Martínez, private communicationPeer Reviewe
Procesos colisionales de H2O + He en jets supersonicos por espectroscopia Raman
Full text linkJ2IFAM 2013 Madrid, February, 13rd-15th 2013Las expansiones supersonicas de gases moleculares y de mezclas gaseosas, son de gran interes para las distintas ramas de la fisica, la quimica, la ingeniera o la astrofisica [1]. Las propiedades de estos sistemas difi#12;eren notablemente de las de un gas en equilibrio termodin
amico, siendo necesario caracterizar las propiedades fuidodinamicas del jet. Para realizar
los estudios cuantitativos de diferentes mezclas de H2O+He en jets supersonicos se ha empleado espectroscopia Raman. Este metodo espectroscopico ha sido mejorado y
adaptado para conseguir un diagnostico preciso de los diferentes estudios. Una caracterstica
a destacar de estas expansiones de mezclas de H2O+He, es que se han conseguido que esten libres de condensacion. Trabajando con presiones parciales de agua en torno a 12 mbar y diferentes proporciones de He. De los experimentos realizados, se obtienen datos de densidades absolutas y poblaciones rotacionales a lo largo de las lineas de flujo. Se observa que la distribucion de los niveles rotacionales de energia mas bajos, se aproxima bien a una distribucion de tipo Boltzmann. Esto nos permite estimar las temperaturas rotacionales, a partir de los espectros de la rama Q (nu1 3657 cm-1) y de la simulacion de los perfi#12;les de estos [2]. La evolucion temporal de las poblaciones rotacionales se interpretara mediante una Ecuacion Maestra que describe la evolucion temporal de las poblaciones rotacionales, obteniendose las las tasas de transferencia colisional inelastica asociadas a cada nivel de rotacion a lo largo del jet.
[1] Tejeda, G.; Mate, B.; Fernandez-Sanchez, J.M. y Montero, S. Physical Review Letters,
76, 34-37, (1996).
[2] Avila, G.; Fernandez, J. M.; Tejeda, G. y Montero, S. Journal of Molecular Spectroscopy,
228 (1), 38-65, (2004)
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