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Uncertainty in charge-coupled devices (CCDs) as UV-vis spectrophotometric detectors is studied here considering that it highly affects the limit of detection of analytical methods. Opposite to photomultiplier-type detectors (PMDs) and diode-array detectors (DADs), where uncertainty is mainly dependent on the photonic signal (shot noise), in CCD detectors uncertainty may come from both independent and dependent effects upon the photonic signal. Shot noise is specially important for high photonic signals in the detector (those for low absorbances) while the uncertainty that is independent of the signal is specially important for low photonic signals in the detector (those for high absorbances). That is, the main source of uncertainty is different depending on the value of the experimental measurement. On the other hand, temperature does not practically affect absorbance measurements, though it is very important for emission measurements (fluorescence, Raman, scattering, etc.). Mathematical equations for uncertainty are proposed with excellent fittings to the experimental data. The equation parameters can be experimentally determined from non-linear regression analysis and used to characterize spectrometers or to test their performance. In order to help buyers and users, some recommendations are finally given considering, among others, cooling, slit, attenuator or fiber optic assemblies.

For most of the twentieth century, Argentina solved the macroeconomic policy trilemma through domestic monetary sovereignty. This article illustrates how the need to finance deficits was behind Argentine sovereignty. We test the hypothesis of fiscal dominance between 1875 and the approval of the Austral Plan in 1991 and find that deficits drove money creation in the long run. The article also reveals how fiscal dominance, in a scenario of increasing currency substitution, helps to explain the dynamics of Argentine inflation in the second half of the twentieth century.

La creatividad se ha convertido en una habilidad esencial en la sociedad actual, definida como la capacidad del ser humano de generar ideas novedosas y valiosas que implican cierto grado de originalidad y de adecuación a la realidad. Además de ser una competencia transversal en el ámbito de la Educación Superior esencial para lograr un aprendizaje de alto nivel y la mejora de los procesos de enseñanza-aprendizaje. Los objetivos de este trabajo son conocer las características creativas (tipo y grado de creatividad) del alumnado de primer curso de Magisterio en Educación Infantil y Primaria y establecer distintos perfiles de estudiantes. Para ello, se ha llevado a cabo un estudio descriptivo, transversal simple y ex post facto con 110 estudiantes de primer curso de Magisterio en Educación Infantil y Primaria, de 18,19 ± 1,81 años. La evaluación del potencial creativo se ha realizado con la Prueba de imaginación Creativa (PIC). Se ha llevado a cabo un análisis descriptivo, correlacional y de clúster para identificar los perfiles en función del tipo de creatividad de dicho alumnado. Los resultados han puesto de manifiesto tres tipos de alumnado, con un grado de creatividad elevado, otro intermedio y otro bajo, en la que la creatividad narrativa tiene un valor preponderante en la configuración de dichos perfiles. Las conclusiones ahondan sobre la especificidad o generalidad de la creatividad y sus implicaciones en la formación del profesorado universitario.

Different methods for a simultaneous determination of several analytes forming volatile compounds at room temperature are described. The main steps of these methods are: continuous generation, collection in a cryogenic trap, revolatilization, measurement of the volatile compounds by Gas Phase Molecular Absorption Spectrometry and resolution by multi-wavelength methods. Several mixtures containing 2, 3 or 4 components have been studied: 1) elements forming covalent hydrides; 2) arsenic organometallic compounds forming volatile gases with a similar structure to arsine; and 3) sulphur species that can evolve volatile compounds. Under the optimum conditions obtained for each mixture, detection limits range from 0.8 ng/mL (dimethylarsinic acid) to 2 microg/mL (SCN(-)).