Análisis de la conducta matemática de estudiantes desde modelos económicos a la teoría de las situaciones didácticas

En este póster se presenta un estudio cuyo objetivo es interpretar modelos económicos (Morton, 1971; Elster, 1989; Carmona, 1997; Bueno, 2004), concretamente los que implican “elección”, “toma de decisiones” y “teoría de juegos”, para analizar la conducta matemática de los estudiantes cuando resuelven problemas en el aula y establecer la relación entre dichos modelos

Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures

Producción CientíficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7 V to +0.3 V. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10−3 M to 1.69·10−3 M with a limit of detection (LOD) of 0.27 mM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16

Habilidades del psicólogo en drogodependencias

Las habilidades del terapeuta constituyen un aspecto fundamental para la consecución de los distintos objetivos que al psicólogo se le plantean en el transcurso de su intervención con el usuario drogodependiente. En este articulo se presenta una revisión de las habilidades que los autores consideran imprescindibles, aportando ejemplos prácticos y con independencia de la orientación teórica del psicólogo. Las habilidades técnicas o profesionales se refieren a conocimientos teóricos y prácticos; el afltocontrol emocional, incluyendo tanto el afrontamiento ef caz por parte del psicólogo de ciertas situaciones ante el usuario, y especificamente si éste es un drogodelincuente, como el afrontamiento del burn out; y por último, las habilidades sociales, en las que se sustenta la interacción entre el psicólogo y el usuario, destacando la asertividad y la empatia. Finalmente se revisan distintos aspectos y principios generales referidos a la ética profesional en la práctica de la Psicologia Clínica

Influence of methane and carbon monoxide in the volumetric behaviour of the anthropogenic CO2: Experimental data and modelling in the critical region

Density measurements of the systems CO 2 + CH 4 at T = 304.21 K and CO 2 + CO at T = 304.21 and 308.15 K were carried out at pressures and compositions of interest in the process of transport and storage of CO 2 (CCS technology): P = 0.1 to 20 MPa, and xCO 2 ≥0.97. From the experimental P––T –xCO 2 data, we have studied the dependence of the isothermal compressibility, the excess molar volume, and the par- tial molar volume of the solute with composition, pressure and temperature within the critical region. We have modelled the volumetric behaviour of these systems with Peng–Robinson, PC-SAFT and GERG Equations of State, thus validating these equations under the conditions considered. Furthermore, we have confirmed the weakly attractive behaviour of these systems by performing a study of the interac- tions between solvent molecules, CO 2 , and those of the solute, CO or CH 4 , using the Krichevskii Function concept and the Kirkwood–Buff Theory. Finally, we have quantified the influence of small amounts of CH 4 and CO in the transport of anthropogenic CO 2 through several normalized parameters, related to the design and operation of the fluid transport process

Un estudio sobre el papel clasificador de las garantías en los mercados de crédito con información asimétrica

This paper tests Bester's (1985, 1987) prediction about the separating role ofcontracts that involve both interest rates and collateral in credit markets. To test thisprediction we use data from natural credit markets and controlled experiments. Using asample of credits to small and medium size firms in Valencia, Spain, we relate twodifferent types of contracts with the ex post risk type of the borrower and other relevantvariables. We then design two incentive compatible contracts and analyze decisionsunder two different experimental treatments, one with moral hazard. Our empiricalresults confirm that borrowers of ex post lower risk choose contracts with highercollateral and lower interest rate. However, we find that moral hazard could reduceseparation. En este trabajo se examinan las tesis de Bester (1985, 1987) sobre el efecto clasificador de los contratos de préstamo que combinan los requisitos de garantía y tipo de interés. Para ello, empleamos dos métodos de análisis complementarios: un análisis empírico tradicional y un análisis experimental. En el primero, sobre una muestra de préstamos a Pymes de la Comunidad Valenciana, relacionamos dos tipos de contratos con el riesgo ex post del prestatario y otras variables relevantes del contrato y/o de la empresa. En el segundo, diseñamos dos contratos incentivo-compatibles y analizamos las elecciones de los individuos en dos entornos: con y sin riesgo moral. Nuestros resultados empíricos y experimentales confirman que los prestatarios de menor riesgo ex post se concentran en los contratos de mayor garantía y menor tipo de interés. Sin embargo, encontramos evidencia experimental de que la existencia de riesgo moral podría reducir la eficacia en la clasificación.Mercado de crédito, garantías, contratos incentivo-compatibles, información asimétrica, riesgo moral Credit markets, incentive compatible contracts, asymmetric information, moral hazard, experiments

High-pressure speed of sound in pure CO2 and in CO2 with SO2 as an impurity using methanol as a doping agent

Reliable speed of sound, c, values in CO2- rich mixtures and pure CO2 are required for carbon capture and storage (CCS) technology but are difficult to determine, particularly at relatively high frequencies. We tested the suitability of methanol as doping agent to obtain accurate c values in CCS systems at 5 MHz. We measured c in seven CO2-rich, CO2 + methanol mixtures between 263.15 and 323.15 K and up to 196.30 MPa, and we extrapolated the values to obtain c in pure CO2. Additionally, we measured c from 263.15 to 373.19 K and up to 190.10 MPa in two CO2-rich, CO2 + SO2 mixtures with the same SO2 composition, which is of interest for CCS, with one mixture doped with methanol. We compared our results for pure CO2 with the literature and the Span and Wagner equation of state (EoS). We validated the PC-SAFT EoS and the modeling with the REFPROP 9 software for the mixtures by comparing the predicted values with our experimental data under the studied conditions. We conclude that methanol is a suitable doping agent to measure c in pure CO2 and CO2-rich mixtures. For the CO2 + SO2 mixtures, the effect of methanol on the experimental values is small and negligible for modeling

Effects of land vs. Aquatic plyometric training on vertical jump

El objetivo de este estudio fue comparar los efectos de dos programas de entrenamiento pliométrico (inmersión vs. seco) sobre el salto vertical. 65 hombres físicamente activos fueron asignados aleatoriamente a tres grupos: entrenamiento pliométrico acuático (EPA, n 20), entrenamiento pliométrico (EP, n=20) y grupo control (GC, n=25). Los grupos EPA y EP entrenaron 2 sesiones por semana durante 10 semanas, mientras que GC no realizó entrenamiento alguno. El volumen de entrenamiento fue aumentado desde 10 series de 10 repeticiones en la primera semana hasta 10 series de 55 repeticiones en la última. Tanto EPA como EP aumentaron su rendimiento en CMJ y SJ con respecto al pretest (P≤0,001) sin encontrar diferencias significativas entre grupos, mientras que GC no mostró cambios. Como conclusión, el EPA puede ser un método alternativo a EP ya que ambos producen similares mejoras sobre el salto vertical y el estrés mecánico producido por EPA es menoThe aim of this study was to compare the effects of two plyometric training program (aquatic vs. land) on vertical jump. 65 male physical education students took part in this study and were randomly assigned to three groups: aquatic plyometric training group (APT, n = 20), plyometric training group (PT, n = 20) and control group (CG, n = 25). The training program was performed for 10 weeks with a frequency of 2 sessions per week. Volume was increased from 10 sets of 10 repetitions to 10 sets of 55 repetitions. Both APT and PT increased the performance in CMJ and SJ with respect to pretest (P ≤ .001), whereas CG remained unaltered. No statistically significant difference was observed between APT and PT. In conclusion, APT may be an alternative method to PT, because both training protocols have produced similar gains in the vertical jump, but APT might cause lower mechanical stres