4,564 research outputs found
Desarrollo de la dimensión emocional y cambio en el auto-concepto matemático a través de resolución de problemas
Esta investigación tiene como interés central dilucidar si alumnos de secundaria pueden lograr, mediante el trabajo en un taller extracurricular de resolución de problemas, competencias emocionales como la toma de conciencia y control de sus emociones, que les permita cambiar de manera positiva su auto-concepto matemático. La información obtenida del trabajo experimental aún se encuentra en proceso de análisis, sin embargo, los resultados preliminares muestran que el gusto y el nivel de auto-confianza como descriptores del auto-concepto matemático son buenos predictores del rendimiento matemático
Iterative design of dynamic experiments in modeling for optimization of innovative bioprocesses
Finding optimal operating conditions fast with a scarce budget of experimental runs is a key problem to speed up the development and scaling up of innovative bioprocesses. In this paper, a novel iterative methodology for the model-based design of dynamic experiments in modeling for optimization is developed and successfully applied to the optimization of a fed-batch bioreactor related to the production of r-interleukin-11 (rIL-11) whose DNA sequence has been cloned in an Escherichia coli strain. At each iteration, the proposed methodology resorts to a library of tendency models to increasingly bias bioreactor operating conditions towards an optimum. By selecting the ‘most informative’ tendency model in the sequel, the next dynamic experiment is defined by re-optimizing the input policy and calculating optimal sampling times. Model selection is based on minimizing an error measure which distinguishes between parametric and structural uncertainty to selectively bias data gathering towards improved operating conditions. The parametric uncertainty of tendency models is iteratively reduced using Global Sensitivity Analysis (GSA) to pinpoint which parameters are keys for estimating the objective function. Results obtained after just a few iterations are very promising.Fil: Cristaldi, Mariano Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Grau, Ricardo José Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Martínez, Ernesto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin
Closed-form equation for natural frequencies of beams under full range of axial loads modeled with a spring-mass system
A new simple closed-form equation that accurately predicts the effect of an arbitrarily large constant axial load, residual stress or temperature shift on the natural frequencies of an uniform single-span beam, with various end conditions, is presented. Its accuracy and applicability range are studied by comparing its predictions with numerical simulations and with the approximate Galef’s and Bokaian’s formulas. The new equation may be understood as a refinement or extension of these two approximate formulas. Significant accuracy and applicability range improvements are achieved, especially near the buckling point and for large and moderate axial load. The new closed-form equation is applicable in the full range of axial load, i.e., from the buckling load to the tensioned-string limit. It also models well the beam-to-string transition region for the eight boundary conditions studied. It works remarkably well in the free-free and sliding-free cases, where it is a near-exact solution. In addition, it yields the natural frequencies of a 1-D spring-mass system that may be used to model tensioned beams, and potentially, more complex systems.Peer ReviewedPostprint (published version
Visual relationships between settlements in the Copper Age and the Bronze Age in Water River basin, Almeria (Spain)
Las relaciones visuales de los asentamientos durante la Prehistoria Reciente en la cuenca
del río Aguas, nos mostrarán la evolución del patrón de asentamiento entre la Edad del Cobre y la Edad
del Bronce en la zona, a través de la cohesión territorial que presenta cada una de estas sociedades.Visual relationships of settlements during the Late Prehistory in the basin of river Aguas,
will show us the evolution of the settlement pattern between the Copper Age and the Bronze Age in
the area, through the territorial cohesion that presents each of these societies
NLO Vertex for a Forward Jet plus a Rapidity Gap at High Energies
We present the calculation of the forward jet vertex associated to a rapidity
gap (coupling of a hard pomeron to the jet) in the BFKL formalism at
next-to-leading order (NLO). Real emission contributions are computed via
Lipatov's effective action. The NLO jet vertex turns out to be finite within
collinear factorization and allows, together with the NLO non-forward gluon
Green's function, to perform NLO studies of jet production in diffractive
events (e.g. Mueller-Tang dijets).Comment: 4 pages, Proceedings of DIFFRACTION 2014 (Primo\v{s}ten, Croatia,
September 2014
The Gluon-Induced Mueller-Tang Jet Impact Factor at Next-to-Leading Order
We complete the computation of the Mueller-Tang jet impact factor at
next-to-leading order (NLO) initiated in arXiv:1406.5625 and presented in
arXiv:1404.2937 by computing the real corrections associated to gluons in the
initial state making use of Lipatov's effective action. NLO corrections for
this effective vertex are an important ingredient for a reliable description of
large rapidity gap phenomenology within the BFKL approach.Comment: 32 pages, many figure
Pig slurry incorporation with tillage does not reduce short-term soil CO2 fluxes
Tillage and organic fertilization impact short-term soil CO2 fluxes. However, the interactive effect of these two management practices has been rarely studied under field conditions. The objective of this study was to evaluate the impact of tillage (NT, no-tillage, and CT, conventional tillage) and fertilization strategy (PS, pig slurry, and MF, mineral fertilizer) on short-term soil CO2 fluxes in a rainfed Mediterranean agroecosystem. Soil CO2 fluxes were measured several times during two tillage and pre-sowing fertilization periods in 2012 and 2013 (7 and 6 times in 2012 and 2013, respectively). In the two years studied, tillage and fertilization significantly affected soil CO2 fluxes, but the interaction between both factors was not significant. The application of PS resulted in a sharp and immediate increase in the soil CO2 flux. One hour after the application of the organic fertilizer, soil CO2 emissions increased from 0.05 to 0.70 g CO2 m−2 h−1 and from 0.08 to 0.82 g CO2 m−2 h−1 in 2012 and 2013, respectively. Unlike fertilization, 1 h after tillage similar soil CO2 fluxes were observed in CT and NT plots. However, after 7 h, larger fluxes were observed in CT compared with NT in both years. Cumulative CO2 flux during the first 24 h after fertilization and tillage was about three- and two-fold greater in PS than in MF and in CT than in NT, respectively. The results of this study showed that in rainfed Mediterranean systems, soil management and fertilization have a noteworthy impact on short-term soil CO2 losses though no interactive effects were observed between both management practices.This research was supported by the Ministry of Economy and Competitiveness of Spain (AGL2010-22050-C03-01/02; AGL2013-49062- C4-4-R) and the COMET-Global project (FACCE-JPI grant)
Curvature of BEOL cantilevers in CMOS-MEMS processes
© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents the curvature characterization results of released back-end-of-line 5 µm-wide cantilevers for two different 0.18-µm 1P6M complementary metal-oxide semiconductor microelectromechanical systems processes. Results from different runs and lots from each foundry are presented. The methodology and accuracy of the characterization approach, based on optical measurements of test cantilever curvature, are also discussed. Special emphasis is given to the curvature average and variability as a function of the number of stacked layers. Analythical equations for modeling the bending behavior of stacked cantilevers as a function of the tungsten (W) vias that join the metal layers are presented. In addition, the effect of various post-processing conditions and design techniques on the curvature of both single and stacked cantilevers is analyzed. In particular, surpassing certain time-dependent temperature stress conditions after release lead to curvature shifts larger than one order of magnitude. Also, the W via design was found to strongly affect the curvature of the test cantilevers.Peer ReviewedPostprint (author's final draft
El Club des Citoyennes Républicanes Révolutionnaires : afirmación femenina y movimiento popular durante la Revolución Francesa
La participación de las mujeres en la Revolución Francesa no debe constituir un capítulo anecdótico en la historiografa sobre ese tema. Nuevos trabajos de investigación y, sobre todo, la celebración en abril de 1989 en Toulouse del Congreso Internacional "Les femmes et la Révolution Francaise" así lo han querido hacer constatar. En esta línea, José Gárriz y Daniel Torras proponen, a través del estudio detallado del Club des Citoyennes Républicianes Révolutionnaires, nuevos elementos de análisis del papel de la mujer dentro del movimiento popular revolucionario.Women's participation on French Revolution must not constitue un anecdotical subject in Revolution historiography. New studies about it and, most of all, the celebration on April 1989 in Toulouse of International Congress "Les femmes et la Révolution Française" have wanted to state that. On this way, José Gárriz and Daniel Torras propose, through a detailed study of the Club des Citoyennes Républicaines Révolutionnaires, new analysis elements of woman role on popular revolutionary movement
UTILIDAD DE LA TOMOGRAFÍA SIMPLE PARA DETERMINAR EL PRONÓSTICO DEL USO DE AUXILIARES AUDITIVOS EN PACIENTES PEDIÁTRICOS TRATADOS EN EL ISEM, DE AGOSTO A DICIEMBRE DE 2012.
Objetivo: Valorar la utilidad predictiva de la TC simple en pacientes con diagnóstico de hipoacusia
para determinar el pronóstico del uso de auxiliares auditivos.
Sede: Centro Médico “Lic. Adolfo López Mateos”, ISEM.
Diseño: Observacional y Transversal tipo Prueba Diagnóstica.
Material y Metódo: Se evaluaron 58 pacientes pediátricos con diagnóstico de hipoacusia tratados
con auxiliares auditivos externos, referidos por el servicio de audiología del H. Dr. Nicolás San Juan
en un período de cinco meses, a los cuales se les realiza Tomografía Simple de oídos. Los
principales hallazgos de la tomografía se correlacionaron con la respuesta obtenida a los auxiliares
auditivos a los tres y seis meses de su adaptación, reportándose estos como útil o no útil por el
servicio de audiología.
Resultados: De los 58 pacientes aceptados en el estudio, al 100% se les realizó Tomografía
Computada (TC) simple de oídos, 62.1% fueron del sexo masculino y el mayor grupo de pacientes
se localizó entre los 2 a 4 años, se encontró que el 15.5% tenían antecedentes familiares para
desarrollar algún tipo de malformación de oídos. Además 46 (93.9%) pacientes que presentaron
malformación en el estudio de imagen (TC) tuvieron una respuesta no útil tras la adaptación de
auxiliares auditivos a los tres y seis meses de iniciado el tratamiento.
Discusión: la tomografía simple de oídos es el método de imagen de elección para el estudio de
pacientes con diagnóstico de hipoacusia o sordera tratados con auxiliares auditivos ya que nos
permite evaluar el pronóstico de dicho tratamiento. En el presente estudio los hallazgos mostraron
una correlación significativa entre la presencia de malformaciones de oído y la respuesta a la
adaptación de auxiliares auditivos como tratamiento inicial de la hipoacusia o sordera en pacientes
pediátricos. La tomografía tiene una alta sensibilidad para clasificar a los pacientes con
malformación en quienes el auxiliar auditivo no será útil
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