Electrodo compósito PVC/TTF-TCNQ modificado con nanopartículas de oro: aplicación para la determinación amperométrica de Paracetamol

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Image quality eigenfunctions for the human eye

This work presents a compact statistical model of the retinal image quality in a large population of human eyes following two objectives. The first was to develop a general modal representation of the optical transfer function (OTF) in terms of orthogonal functions and construct a basis composed of cross-correlations between pairs of complex Zernike polynomials. That basis was not orthogonal and highly redundant, requiring the application of singular value decomposition (SVD) to obtain an orthogonal basis with a significantly lower dimensionality. The first mode is the OTF of the perfect system, and hence the modal representation, is highly compact for well-corrected optical systems, and vice-versa. The second objective is to apply this modal representation to the OTFs of a large population of human eyes for a pupil diameter of 5 mm. This permits an initial strong data compression. Next, principal component analysis (PCA) is applied to obtain further data compression, leading to a compact statistical model of the initial population. In this model each OTF is approximated by the sum of the population mean plus a linear combination of orthogonal eigenfunctions (eigen-OTF) accounting for a selected percentage (90%) of the population variance. This type of models can be useful for Monte Carlo simulations among other application

Coastal Cliff Exposure and Management

[Abstract:] Coastal cliffs cover about 75% of the world's coastlines. Many of these cliffs suffer severe erosion problems, which are mainly caused by wave action and lead to important damages. The main objective of this work is to propose and apply a methodology to characterize and map wave exposure levels for the management of cliff coasts. The methodology proposed consists of a number of steps. First, a statistical characterization of the wave climate in deep water is performed. Second, relevant sea states are propagated towards the cliff by means of a numerical model. Then, the results are used to assess the distribution of significant wave heights and wave power along the cliff toe. Finally, four exposure levels are defined based on the wave power values at the cliff, and exposure zones are mapped accordingly along the cliff. This approach is illustrated with a case study – the Catedrales Cliffs and Beach, a tourism hotspot in Galicia (NW Spain) where erosion caused loss of human life. We find that exposure levels are primarily influenced by the nearshore bed morphology, which controls wave refraction, shoaling and breaking, as well as by the geometry and orientation of the cliff, with some parts more exposed than others to the prevailing wave direction. On the islets off the cliff the windward faces have a greater level of exposure, since the leeward faces are protected by the islets themselves and lower water depths. The rocky outcrops that occur at the cliff toe in some sections act as emerged (submerged) breakwaters under low (high) tide conditions, dissipating wave power and thus reducing wave exposure. The methodology proposed in this work enables coastal managers to prevent the personal and material damages derived from cliff erosion by focusing remedial measures where they are most needed.Ministerio de Ciencia, Innovación y Universidades; FJCI-2017-3178

Evolución geoquímica de la salmuera de la laguna de Alcahazo, Pedro Muñoz (Ciudad Real).

La Mancha, por sus condiciones climáticas y geomorfológicas, es una región natural en la que se forman frecuentes encharcamientos que derivan hacia sistemas tipo "sebkha" en los que se produce precipitación de sales por evaporación. En la laguna se han determinado las siguientes fases minerales: sulfato magnésico (epsomita, hexahidrita, pentahidrita y kieserita), sulfato cálcico (yeso), cloruro sódico (halita) y cloruro magnésico (bischofita). Las aguas de la laguna, en el período de máxima dilución, presentan una composición marcadamente sulfatada, con alto contenido en cloruros, magnesio y sodio. En laboratorio se ha realizado el seguimiento de la evolución de la salmuera en condiciones equivalentes a las naturales, estableciéndose su correlación con la secuencia teórica de precipitación según VALYASHKO. Por último, se hace una valoración más detallada de los contenidos en estroncio, lo que permite establecer la hipótesis, en función de los aportes, de que esta laguna funciona como un sistema cerrado con recargas limitadas a aportes de lluvia en su cuenca de recepción

Model and neural control of the depth of anesthesia during surgery

At present, the experimentation of anesthetic drugs on patients requires a regulation protocol, and the response of each patient to several doses of entry drug must be well known. Therefore, the development of pharmacological dose control systems is a promising field of research in anesthesiology. In this paper it has been developed a non-linear compartmental pharmacokinetic-pharmacodynamical model which describes the anesthesia depth effect on a sufficiently reliable way over a set of patients with the depth effect quantified by the Bi-Spectral Index. Afterwards, an Artificial Neural Network (ANN) predictive controller has been designed based on the depth of anesthesia model so as to keep the patient on the optimum condition while he undergoes surgical treatment. For the purpose of quantifying the efficiency of the neural predictive controller, a classical proportional-integral-derivative controller has also been developed to compare both strategies. Results show the superior performance of predictive neural controller during Bi- Spectral Index reference tracking.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Electrochemical Determination of the Glyphosate Metabolite Aminomethylphosphonic Acid (AMPA) in Drinking Waters with an Electrodeposited Copper Electrode

Carbon electrodes with in situ electrodeposited copper are used to the determination of aminomethylphosphonic acid (AMPA), the major metabolite of the herbicide Glyphosate (N-(phosphonomethyl) glycine) in drinking waters. The oxidation signal to form Cu(II) ions changes after the addition of AMPA due to the formation of a complex, this effect being used to develop an analytical method simpler, inexpensive and faster than those conventionally used. Glassy carbon and carbon paste electrodes are investigated, concluding that the last is more suitable for routine analysis. Samples of drinking water fortified with different AMPA concentrations have been used to test the method

Nueva fórmula para la estimación agroclimática de las horas de frío

p.139-144Utilizando valores climáticos corrientes se desarrolló una fórmula para estimar la magnitud del enfriamiento disponible durante el descanso de frutales criófilos al cual se lo considera extendido entre el 1º de mayo y el 31 de agosto. Para ello se utilizó la información climática de horas de frío medias mensuales de la serie 1971-2000 calculadas mediante la formula de Parton y Logan (1981) aplicada a valores diarios. Los valores obtenidos mediante la nueva fórmula propuesta manifiestan excelente correlación con los valores calculados, observándose entre ambas series diferencias muy pequeñas con un error absoluto medio de alrededor de 3 por ciento

New Biosensor for Phenols Compounds Based on Gold Nanoparticle-Modified PVC/TTF-TCNQ Composite Electrode

A gold nanoparticle-modified PVC/TTF-TCNQ composite electrode with tyrosinase enzyme is proposed as electrochemical biosensor for detecting phenolic compounds in musts and wines samples using phenol and catechol as standards. The work potential was 0 V both in batch and in FIA system (linear range from 0.6 μM up to 10.0 μM), with a detection limit of 7.9 x 10-7 M for phenol and 6.43 x 10-7 M for catechol. The good correlation between the results obtained with the biosensor and those achieved with the Folin–Ciocalteu reference method enables that it can be used for rapid and almost automated estimation of the “total phenolics” and “high antioxidant” fraction of must and commercial wines

Electrocatalytic Oxidation of Acetaminophen on a PVC/TTF-TCNQ Composite Electrode Modified by Gold Nanoparticles: Application as an Amperometric Sensor

This work shows the electrocatalytic activity towards the oxidation of acetaminophen of a composite electrode PVC/TTF-TCNQ modified with gold nanoparticles. Owing to a good linear relationship between acetaminophen concentration and current response at lower oxidation potential it is proposed as a new alternative for amperometric determination of acetaminophen. Besides the good catalytic activity (Eapp = 0.425 V), the proposed sensor shows high reproducibility, long-term stability, low cost and can be used both in batch and in FIA systems. In batch, it was obtained a linear range for acetaminophen over a range of 1 to 800 μM with a detection limit of 0.66 μM and a correlation coefficient of 0.997 with a slope (sensitivity) of 53 mA M-1. In FIA, a sensitivity of 9.9 ± 0.15 mA M-1 and a linear regression coefficient (r) of 0.999 were obtained for a linear range for acetaminophen between 1 to 800 μM. The detection limit (s/n = 3) was 8.9 μM