Gas identification with tin oxide sensor array and self-organizing maps: adaptive correction of sensor drifts

Low-cost tin oxide gas sensors are inherently nonspecific. In addition, they have several undesirable characteristics such as slow response, nonlinearities, and long-term drifts. This paper shows that the combination of a gas-sensor array together with self-organizing maps (SOM's) permit success in gas classification problems. The system is able to determine the gas present in an atmosphere with error rates lower than 3%. Correction of the sensor's drift with an adaptive SOM has also been investigate

Análisis dinámico de atmósferas con matrices de sensores mediante procesado de señal no-lineal

El presente trabajo se enmarca dentro de las tareas centradas en el campo de modelización y procesado de señal, desarrolladas en el Departament d’Electrònica de la Facultad de Física de la Universitat de Barcelona. En su concepción de nivel más amplio, el trabajo demuestra la posibilidad de trasladar y aplicar con eficiencia las técnicas de procesado y modelización dinámica no lineal al ámbito de los sistemas de medida de gases. Son relativamente abundantes en la literatura otras aproximaciones más simples a esta temática y en este ámbito. Así, es posible encontrar en la literatura trabajos enfocados hacia la modelización estática-lineal, estática-no lineal y dinámica-lineal. Sin embargo, no existían antes de este trabajo aportaciones bajo el enfoque dinámico y no lineal en la modelización de sistemas de medida gaseosos. Por otra parte, el trabajo aborda además el problema desde el punto de vista de la multidimensionalidad junto con la restricción del uso de un reducido número de datos; factores éstos que aportan dificultad adicional a la vez que valor añadido a la solución. En lo concreto, el trabajo se centra en el análisis y modelización del comportamiento de un sistema de medida de gases basado en sensores QMB frente a cambios rápidos de dos concentraciones en una mezcla binaria de gases (tolueno y octano) en aire sintético y bajo régimen de altas concentraciones (miles de ppm). Frente a este problema, la calibración estática es incapaz de aportar una solución con un error tolerable. Por primera vez se ha abordado, frente a la solución estática, la modelización dinámica y no lineal de sistemas analizadores de gases, ofreciendo esta aproximación resultados óptimos. Los experimentos diseñados, orientados hacia la confección de los modelos, fueron fundamentalmente dos: 1) Sistema sometido a concentraciones en forma de escalón 2) Sistema sometido a señales de concentración en forma de ruido blanco con densidad de probabilidad gausiana. Los modelos generados son también de dos tipos: 1) Modelos directos: desde la entrada hacia la salida 2) Modelos inversos: desde la salida hacia la entrada Para la resolución del problema se han probado diferentes estimaciones, como estimadores de correlación, estimaciones paramétricas, series de Volterra, series de Wiener, modelos de cajas y redes neuronales. De entre todos ellos, los modelos basados en series de Wiener y en redes neuronales han demostrado una mayor eficiencia. Se demuestra que estos modelos son capaces de explotar la información del sistema estudiado hasta el límite de la resolución experimental, tanto en la modelización directa como en la inversa. Aparte de la tarea estrictamente relacionada con la modelización, se ha iniciado con este trabajo la construcción de una estación de test de sensores de gas que en la actualidad y después de diversas aportaciones del grupo de trabajo, es un complejo sistema de medición y test capaz de realizar una gran variedad de pruebas relacionadas con gases, dotando al departamento de una línea de trabajo nueva, potente y bien equipada.The work demonstrates the possibility of efficiently transferring and applying nonlinear dynamic processing and modeling techniques to the field of gas measurement systems. It is possible to find works focused on static-linear, static-non-linear and dynamic-linear modeling. However, prior to this work there were no contributions under the dynamic and non-linear approach in the modeling of gas measurement systems. On the other hand, the work also addresses the problem from the point of view of the curse of dimensionality: multidimensional problems with scarcity of data. The work focuses on the analysis and modeling of the behavior of a gas measurement system based on QMB sensors against rapid changes of two concentrations in a binary mixture of gases (toluene and octane) in synthetic air and under regime of high concentrations (thousands of ppm). The static calibration is unable to provide a solution with a tolerable error. The dynamic and nonlinear modeling of gas analyzer systems has been performed with optimal results. The experiments designed, oriented towards the preparation of the models, were fundamentally two: 1) System with step-like gas concentration inputs 2) System excited with gas input signals whose concentration values follow a white noise with Gaussian probability density. The generated models are also of two types: 1) Direct models: from the input to the output 2) Inverse models: from the output to the input Different approaches have been tested, such as correlation estimators, parametric estimates, Volterra series, Wiener series, box models and neural networks. Models based on Wiener series and on neural networks have demonstrated a greater efficiency. It is shown that these models are able to extract the information of the studied system until experimental resolution limit, in both direct and inverse modeling. Apart from the task related to gas sensor modeling, the development of a test station for gas sensors has been addressed. This task has been developed by the research group and it is capable to perform a wide variety of gas experiments, providing the department with a new, powerful and well-equipped line of work

Análisis dinámico de atmósferas con matrices de sensores mediante procesado de señal no-lineal

[spa] El presente trabajo se enmarca dentro de las tareas centradas en el campo de modelización y procesado de señal, desarrolladas en el Departament d’Electrònica de la Facultad de Física de la Universitat de Barcelona. En su concepción de nivel más amplio, el trabajo demuestra la posibilidad de trasladar y aplicar con eficiencia las técnicas de procesado y modelización dinámica no lineal al ámbito de los sistemas de medida de gases. Son relativamente abundantes en la literatura otras aproximaciones más simples a esta temática y en este ámbito. Así, es posible encontrar en la literatura trabajos enfocados hacia la modelización estática-lineal, estática-no lineal y dinámica-lineal. Sin embargo, no existían antes de este trabajo aportaciones bajo el enfoque dinámico y no lineal en la modelización de sistemas de medida gaseosos. Por otra parte, el trabajo aborda además el problema desde el punto de vista de la multidimensionalidad junto con la restricción del uso de un reducido número de datos; factores éstos que aportan dificultad adicional a la vez que valor añadido a la solución. En lo concreto, el trabajo se centra en el análisis y modelización del comportamiento de un sistema de medida de gases basado en sensores QMB frente a cambios rápidos de dos concentraciones en una mezcla binaria de gases (tolueno y octano) en aire sintético y bajo régimen de altas concentraciones (miles de ppm). Frente a este problema, la calibración estática es incapaz de aportar una solución con un error tolerable. Por primera vez se ha abordado, frente a la solución estática, la modelización dinámica y no lineal de sistemas analizadores de gases, ofreciendo esta aproximación resultados óptimos. Los experimentos diseñados, orientados hacia la confección de los modelos, fueron fundamentalmente dos: 1) Sistema sometido a concentraciones en forma de escalón 2) Sistema sometido a señales de concentración en forma de ruido blanco con densidad de probabilidad gausiana. Los modelos generados son también de dos tipos: 1) Modelos directos: desde la entrada hacia la salida 2) Modelos inversos: desde la salida hacia la entrada Para la resolución del problema se han probado diferentes estimaciones, como estimadores de correlación, estimaciones paramétricas, series de Volterra, series de Wiener, modelos de cajas y redes neuronales. De entre todos ellos, los modelos basados en series de Wiener y en redes neuronales han demostrado una mayor eficiencia. Se demuestra que estos modelos son capaces de explotar la información del sistema estudiado hasta el límite de la resolución experimental, tanto en la modelización directa como en la inversa. Aparte de la tarea estrictamente relacionada con la modelización, se ha iniciado con este trabajo la construcción de una estación de test de sensores de gas que en la actualidad y después de diversas aportaciones del grupo de trabajo, es un complejo sistema de medición y test capaz de realizar una gran variedad de pruebas relacionadas con gases, dotando al departamento de una línea de trabajo nueva, potente y bien equipada.[eng] The work demonstrates the possibility of efficiently transferring and applying nonlinear dynamic processing and modeling techniques to the field of gas measurement systems. It is possible to find works focused on static-linear, static-non-linear and dynamic-linear modeling. However, prior to this work there were no contributions under the dynamic and non-linear approach in the modeling of gas measurement systems. On the other hand, the work also addresses the problem from the point of view of the curse of dimensionality: multidimensional problems with scarcity of data. The work focuses on the analysis and modeling of the behavior of a gas measurement system based on QMB sensors against rapid changes of two concentrations in a binary mixture of gases (toluene and octane) in synthetic air and under regime of high concentrations (thousands of ppm). The static calibration is unable to provide a solution with a tolerable error. The dynamic and nonlinear modeling of gas analyzer systems has been performed with optimal results. The experiments designed, oriented towards the preparation of the models, were fundamentally two: 1) System with step-like gas concentration inputs 2) System excited with gas input signals whose concentration values follow a white noise with Gaussian probability density. The generated models are also of two types: 1) Direct models: from the input to the output 2) Inverse models: from the output to the input Different approaches have been tested, such as correlation estimators, parametric estimates, Volterra series, Wiener series, box models and neural networks. Models based on Wiener series and on neural networks have demonstrated a greater efficiency. It is shown that these models are able to extract the information of the studied system until experimental resolution limit, in both direct and inverse modeling. Apart from the task related to gas sensor modeling, the development of a test station for gas sensors has been addressed. This task has been developed by the research group and it is capable to perform a wide variety of gas experiments, providing the department with a new, powerful and well-equipped line of work

Paleopopulations and ecological connectivity in the Natura 2000 Network: proposal for the serpentine‑soil Spanish firs of Sierra Bermeja (Serranía de Ronda)

Funding for open access publishing: Universidad de Granada/ CBUA. This research has been supported by a contract for Univer- sity Teacher Training (Formación de Profesorado Universitario) (Ref. 18/03023) from the Spanish Ministry of Education, Culture and Sports (Ministerio de Educación, Cultura y Deportes del Gobierno de España), and research projects financed by the State Research Agency (SRA) and European Regional Development Fund (ERDF): PALEOPINSAPO (CSO2017-83576-P), MED-REFUGIA (RTI2018-101714-B-I00) and TED2021-132631B-I00; Andalusian Plan for Research, Development and Innovation: Oromed-Refugia (P18-RT- 4963); and ERDF Opera- tional Programme in Andalusia (EU regional programme): ForestMed (A-RNM-688-UGR20).One of the conservation priorities of the Natura 2000 Network is the ecological connectivity of forests and species of com- munity interest to facilitate compliance with the obligations of the EU Habitats Directive. The location of paleo-populations and past distribution areas is a first step towards creating an ecological corridor which, with the protection enjoyed by Special Areas of Conservation, could positively impact the resilience of forest species in the face of Climate Change. The endangered relict forests of Spanish fir (Abies pinsapo) are endemic in the Serranía de Ronda (Baetic Cordillera, Southern Spain) and form a highly fragmented habitat of community interest. Amongst these forests, the Spanish fir forests that grow on serpentine soils are particularly interesting. This ultramafic mountain range has suffered the highest recurrence of forest fires in all the Serranía de Ronda, and as a result, the Spanish fir forests have been subject to processes of local extinction throughout history. In this research, we used pedoanthracology to uncover ancient locations of Abies pinsapo; in this way, forest fires are the main cause of the disappearance of this emblematic species in Sierra Bermeja, and their charcoal remains allowed us to make a precise reconstruction of its past distribution area. On the basis of the data obtained, an ecological corridor linking these relict forests was proposed. This corridor has now begun to be implemented with the participation of public and private social agents.Universidad de Granada/CBUASpanish Ministry of Education, Culture and Sports (Ministerio de Educacion, Cultura y Deportes del Gobierno de Espana) 18/03023State Research Agency (SRA)European Regional Development Fund (ERDF): PALEOPINSAPO CSO2017-83576-PEuropean Regional Development Fund (ERDF): MED-REFUGIA RTI2018-101714-B-I00European Commission TED2021-132631B-I00Andalusian Plan for Research, Development and Innovation: Oromed-Refugia P18-RT- 4963ERDF Operational Programme in Andalusia (EU regional programme): ForestMed (A-RNM-688-UGR2

The history of Abies pinsapo during the Holocene in southern Spain, based on pedoanthracological analysis

The results of this research are part of the contract for Formacion de Profesorado Universitario (University Teacher Training) (Ref. 18/03023) financed by the Ministerio de Educacion del Gobierno de Espana (Ministry of Education of the Government of Spain), and research projects PALEOPINSAPO (CSO2017-83576-P), Med-Refugia (Ref. RTI2018-101714-B-I00), Oromed-Refugia (Ref. P18-RT-4963) and Relic-Flora 2 (Ref. B-RNM-404-UGR18), dependents on the Ministerio de Economia y Competitividad del Gobierno de Espana y la Junta de Andalucia (Ministry of the Economy and Competitiveness of the Government of Spain and the Regional Government of Andalusia.The aim of this research is to reconstruct the ancient distribution area of Abies pinsapo Boiss. (Spanish fir) in the Serranía de Ronda region, southern Spain, during the Holocene. The main method was pedoanthracological analysis, the study of non-archaeological charcoal found in natural soils. In this research a total of 37 soil excavations were done in several mountain ranges with potentially favourable places for firs to have grown in the past. Specific sites and places such as hillsides, endorheic basins (with no outflow), sinkholes, summits and mountain passes were selected on the basis of evidence from a range of different sources including ancient documents, pollen studies and species distribution models. The soil samples collected from these sites were prepared in the laboratory and the charcoal was identified and radiocarbon dated. Statistical and cartographic analyses were also done. The study revealed evidence of past populations of Abies sp. in places where it is no longer found today. A total of 47 different chronologies were obtained from these sites with ages ranging between 9,931 cal bp and 78 cal bp. In addition, the wide variations in the charcoal values enabled us to make an initial estimate of the importance of ancient forest fires in different places in the Serranía de Ronda. When this information has been considered with all the other available data sources, it will be an essential resource for the efficient management of relict fir woods in southern Spain.Ministerio de Educacion del Gobierno de Espana (Ministry of Education of the Government of Spain) 18/03023dependents on the Ministerio de Economia y Competitividad del Gobierno de Espana y la Junta de Andalucia (Ministry of the Economy) CSO2017-83576-P RTI2018-101714-B-I00 P18-RT-4963 B-RNM-404-UGR18Junta de AndaluciaCompetitiveness of the Government of Spai

Motivations and Reasons for Exercising in Water: Gender and Age Differences in a Sample of Spanish Exercisers

The purposes of this study were, on the one hand, to relate the reasons for exercising with self-determination and, on the other, to check gender and age differences with a sample of 311 exercisers in water. The data were collected using the Behavioral Regulation in Exercise Questionnaire–2 and Motives for Physical Activities Measure–Revised. A positive and significant correlation was seen between self-determination and the reasons for exercise, with self-determination predicting 22% by enjoyment and 8% by fitness/health reasons. Similarly, the multivariate analysis showed that the women had more self-determination than the men and that they also rated fitness/health, social, enjoyment, and appearance reasons more highly. In addition, older exercisers rated the fitness/health reason more highly than the younger people. It seems that exercising in water is more satisfying for women than for men

Enriched-biochar application increase broccoli nutritional and phytochemical content without detrimental effect on yield

BACKGROUND Soil fertility is a major concern during vegetable production. Conventional versus organic fertilization has been studied in order to conserve soil properties. While some reports point out an increase in food nutritional properties, the loss of crop yield under organic conditions continues to be a problem. Thus, an experiment with broccoli in the field was carried out, comparing crop management under conventional fertilization (CF) and two soil amendment treatments: manure pellet (M) and an enriched-biochar (EB) supplemented by an organic fertilizer (AND) applied alone (M + CF; EB+AND) or in combination (M + EB + AND). Crop yield and the nutritional properties in the flowering heads (mineral content, phenolic compounds and glucosinolates (GSLs)), were determined. RESULTS Enriched-biochar and manure as a standalone amendment resulted in higher crop yield regarding CF, but not when they were applied in combination. The number of flowering heads with no-commercial characteristics was lower after enriched-biochar soil application. Finally, enriched-biochar treatment enhanced NO3−, PO43− and SO42− levels in the flowering heads, and some of the ion contents can be associated with mineral changes in the soil after the biochar amendment. Also, the contents of phenolic compounds and indole GSLs were higher after enriched-biochar application compared with the other treatments, GSL increase being due to the higher percentage of sulfur in the plant rather that an adequate N/S ratio. CONCLUSION Application of enriched-biochar amendment in the cultivation of broccoli is appropriate, since there are no losses of yield and an increase in nutritional compounds in the flowering heads. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.The authors thank Carbuna SL for the supply of biochar. The authors thank Pedro Mínguez from El Mirador-CDTA experimental station for availability of the production data. The authors thank Diego Moreno from CEBAS-CSIC for support with glucosinolate analysis. Experiments were funded by Carbuna AG

The potential of ion mobility spectrometry (IMS) for detection of 2,4,6-trichloroanisole (2,4,6-TCA) in wine

The off-flavor of "tainted wine" is attributed mainly to the presence of 2,4,6-trichloroanisole (2,4,6-TCA) in the wine. In the present study the atmospheric pressure gas-phase ion chemistry, pertaining to ion mobility spectrometry, of 2,4,6-trichloroanisole was investigated. In positive ion mode the dominant species is a monomer ion with a lower intensity dimer species with reduced mobility values (K0) of 1.58 and 1.20 cm2 V−1 s−1, respectively. In negative mode the ion with K0 = 1.64 cm2 V−1 s−1 is ascribed to a trichlorophenoxide species while the ions with K0 = 1.48 and 1.13 cm2 V−1 s−1 are attributed to chloride attachment adducts of a TCA monomer and dimer, respectively. The limit of detection of the system for 2,4,6-TCA dissolved in dichloromethane deposited on a filter paper was 2.1 μg and 1.7 ppm in the gas phase. In ethanol and in wine the limit of detection is higher implying that pre-concentration and pre-separation are required before IMS can be used to monitor the level of TCA in wine

Europe's southernmost interglacial refugia as sentinels for the local extinction of mountain conifers

This research has been supported by a contract for University Teacher Training (Formación de Profesorado Universitario) (Ref. 18/03023) from the Spanish Ministry of Education, Culture and Sports (Ministerio de Educación, Cultura y Deportes del Gobierno de España), and research projects financed by the State Research Agency (SRA) and European Regional Development Fund (ERDF): PALEOPINSAPO (CSO2017-83576-P), MED-REFUGIA (RTI2018-101714-B-I00) and TED2021-132631B-I00; Andalusian Plan for Research, Development and Innovation: Oromed-Refugia (P18-RT- 4963); and ERDF Opera- tional Programme in Andalusia (EU regional programme): ForestMed (A-RNM-688-UGR20).The Serrania de Ronda is an exceptional palaeoecological laboratory for studying the dynamics of vegetation over time, due to its strategic geographical location at a biogeographical crossroads and its proven historical legacy. Many of the mountains that form part of this territory are today practically deforested, such as Sierra Blanca, whose geographic location at the heart of the Serranía de Ronda means that it has enormous potential as a bio- geographical crossroads: the occasional presence of Abies pinsapo, Pinus pinaster and Quercus rotundifolia suggests that it was once covered by a mixed forest of conifers and broad-leaved trees. The lack of environmental research in Sierra Blanca has facilitated the installation of large quarries, which have led to its exclusion from the Sierra de las Nieves National Park, which was created in 2021. We applied the pedoanthracological methodology, which has enabled us to discover paleo-populations of A. pinsapo and Pinus sylvestris-type. The results confirm that co- niferous forests previously covered a much wider area during the Holocene. These findings reinforce the role of Sierra Blanca as a high-altitude refuge for conifers during the warm stages of the Holocene and as a sentinel for the local extinction of mountain conifers. This information could help improve its management and conservation.Spanish Government 18/03023State Research Agency (SRA)European Commission CSO2017-83576-P, RTI2018-101714-B-I00, TED2021-132631B-I00Andalusian Plan for Research, Development and Innovation P18-RT-4963ERDF Operational Programme in Andalusia (EU regional programme) A-RNM-688-UGR2