476 research outputs found

    Un enfoque de regionalización simple como alternativa para obtener datos de lluvia en una cuenca de zona tropical y no monitoreada

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    (Eng) The availability of rainfall information with high spatial resolution is of fundamental importance in many applications in the field of water resources. Commonly, the rainfall data in developing countries are obtained by rain gauge stations. However, many studies show that traditional measures based on rain gauge stations may not reflect the spatial variation of rainfall effectively. Although satellite data have been widely used around the world, when applied to local regions the spatial resolution of these products is too coarse. In this paper, an approach to identify a downscaling method through geostatistical regionalization to improve water resources models with short spatial and temporal scales and with limited rainfall data is presented. Three different models were applied: Cokriging, Inverse Distance Weight (IDW) and Kriging. Statistical parameters such as mean absolute error (MAE) and root mean square error (RMSE) were computed. A cross-validation process showed a better fit for most of the stations using the Cokriging method. The regionalization results were quite comparable with the rain gauge stations data. Although the model outcomes did not improve remarkably, the contribution of this approach may have the potential to provide useful rainfall data at spatial scales shorter than the present resolution.(Spa) La disponibilidad de información de precipitación con alta resolución espacial es de fundamental importancia en el campo de los recursos hídricos. Comúnmente, los datos de lluvia se obtienen mediante estaciones pluviométricas. Sin embargo, investigaciones demuestran que las medidas tradicionales pueden no reflejar la variación espacial de la precipitación efectiva. Por otro lado, cuando se aplican datos de satélite a regiones locales su resolución espacial es demasiado gruesa. Este trabajo presenta un enfoque para identificar un método de reducción de escala mediante la regionalización geoestadística para mejorar los modelos de recursos hídricos que contienen escalas cortas espaciales y temporales y datos de precipitación limitada. Se aplicaron tres modelos diferentes: Cokriging, Peso Inverso de la Distancia (IDW) y Kriging. Se calcularon parámetros estadísticos como el error medio absoluto (MAE) y la raíz del error cuadrático medio (RMSE). Un proceso de validación cruzada mostró un mejor ajuste para la mayoría de las estaciones utilizando el método Cokriging. Los resultados de regionalización fueron comparables con los datos de estaciones pluviométricas. Aunque los resultados de los modelos no mejoraron notablemente, la contribución de este enfoque puede tener el potencial de proporcionar datos de precipitación útiles a escalas espaciales más cortas que la presente resolución

    New Method for Increasing Sustainable Agricultural Yield

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    The main objective of this study is to look for a new method, to obtain the maximum production, and the minimum economic and environmental cost. Scientific advances in bioclimatology have brought a greater understanding of the functioning of plant individuals, populations and communities, and the study and interpretation of bioclimatic indices reveals the close relationship between the values of these indices and crop yields. In cases where insufficient meteorological data are available to allow the various formulas to be applied, thermoclimatic and ombroclimatic bioindicators must be used, some of which have been collected by us in previous works. This paper contains a bioclimatic study of the southern Iberian Peninsula in relation to the main olive varieties grown in these territories. We establish the values of some key indices for cultivation: continentality index (Ic), which determines the annual thermal range and allows us to establish the period of vegetative activity (PAV); the ombrothermic index (Io), which measures the ombrotype in the different sites; and the thermicity and compensated thermicity index, which denote the thermotype in the territory (It/Itc). In the relationship between the value of the bioclimatic indices and olive production, good fits are obtained in the regression analysis with R2> 0.90, and is very positive influence of the different parameters used. In conclusion the greatest influence on the production of Ic is between 18.5-19.5, Io 3.5-4.5 and It / Itc 320-350. This allows to obtain areas of maximum production with a lower economic cost

    Electrochemical study on an activated carbon cloth modified by cyclic voltammetry with polypyrrole/anthraquinone sulfonate and reduced graphene oxide as electrode for energy storage

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    [EN] This work describes a two-step procedure for the electrochemical coating of reduced graphene oxide (RGO) and polypyrrole anthraquinone sulfonate (PPyAQS) onto an activated carbon cloth (ACC) by cyclic voltammetry (CV). The textile samples were characterized by CV, electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge measurements using a sandwich-type (electrode/separator/electrode) cell designed to operate in three or two-electrode configurations. The presence of RGO onto the ACC surface optimized the electrosynthesis of PPyAQS and reinforced the stability of the polymer with the number of charge/discharge cycles. A retention capacity of 90% after 100 charge-discharge cycles together with an energy density of 7.8¿×¿10¿4¿W¿h¿cm¿2 at a power density of 1.8¿×¿10¿3¿W¿cm¿2 were obtained for the ACC/RGO/PPyAQS sample. The analyses by field emission scanning electron microscopy (FESEM) showed the RGO veils-like and PPyAQS glomerular structures covering the ACC-fibers. The Fourier transform infrared spectroscopy (FTIR) analyses not only detected the presence of PPy and AQS, but also, the changes in the molecular structure of PPyAQS, depending on its oxidation state, as consequence of the redox reactions occurred in the charge/discharge processes in the two-electrode cell.The authors wish to acknowledge to Chemviron Carbon who kindly donated the ZORFLEX® activated carbon fabric. The authors wish to thank the Spanish Agencia Estatal de Investigación de Economía (AEI) and European Union (FEDER funds) for the financial support (contract MAT2016-77742-C2-1-P). Tim Vickers is gratefully acknowledged for help with the English revision. Electron Microscopy Service of the UPV (Universitat Politècnica de València) is gratefully acknowledged for help with FESEM characterization.Fernández Sáez, J.; Bonastre Cano, JA.; Molina Puerto, J.; Cases, F. (2018). Electrochemical study on an activated carbon cloth modified by cyclic voltammetry with polypyrrole/anthraquinone sulfonate and reduced graphene oxide as electrode for energy storage. European Polymer Journal. 103:179-186. https://doi.org/10.1016/j.eurpolymj.2018.04.018S17918610

    ISA S88 / Loose Coupling Based Solution for Production Control Software Reusability

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    A solution for the problem of reusability of software system for batch production systems is proposed. It is based on ISA S88 standard that prescribes the abstraction of elements in the manufacturing system that is equipment, processes and procedures abstraction, required to make a product batch. An easy to apply data scheme, compatible with the standard, is developed for management of production information. In addition to flexibility provided by the S88 standard, software system reusability requires a solution supporting manufacturing equipment reconfigurability. Toward this end a coupling mechanism is developed. A software tool, including these solutions, was developed and validated at laboratory level, using product manufacturing information of an actual plant

    CALHM1 and its polymorphism P86L differentially control Ca<sup>2+</sup> homeostasis, mitogen-activated protein kinase signaling, and cell vulnerability upon exposure to amyloid β

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    The mutated form of the Ca2+ channel CALHM1 (Ca2+ homeostasis modulator 1), P86L-CALHM1, has been correlated with early onset of Alzheimer’s disease (AD). P86L-CALHM1 increases production of amyloid beta (Ab) upon extracellular Ca2+ removal and its subsequent addback. The aim of this study was to investigate the effect of the overexpression of CALHM1 and P86L-CALHM, upon Ab treatment, on the following: (i) the intracellular Ca2+ signal pathway; (ii) cell survival proteins ERK1/2 and Ca2+/cAMP response element binding (CREB); and (iii) cell vulnerability after treatment with Ab. Using aequorins to measure the effect of nuclear Ca2+ concentrations ([Ca2+]n) and cytosolic Ca2+ concentrations ([Ca2+]c) on Ca2+ entry conditions, we observed that baseline [Ca2+]n was higher in CALHM1 and P86L-CALHM1 cells than in control cells. Moreover, exposure to Ab affected [Ca2+]c levels in HeLa cells overexpressing CALHM1 and P86L-CALHM1 compared with control cells. Treatment with Ab elicited a significant decrease in the cell survival proteins p-ERK and p-CREB, an increase in the activity of caspases 3 and 7, and more frequent cell death by inducing early apoptosis in P86L-CALHM1- overexpressing cells than in CALHM1 or control cells. These results suggest that in the presence of Ab, P86L-CALHM1 shifts the balance between neurodegeneration and neuronal survival toward the stimulation of pro-cytotoxic pathways, thus potentially contributing to its deleterious effects in AD.This work was partly supported by the following grants: Ministerio de Economía y Competitividad, FPU Program, Refs. AP2009/0343 (AJMO) and AP2010/1219 (IB). ARN: FIS PI10/01426. MGL: Ministerio de Economía y Competitividad, Ref. SAF2012-23332. MFCA: Consolidación de grupos de investigación UAM-CAM 1004040047. We also thank Fundación Teófilo Hernando, Madrid, Spain, for their continued suppor

    Influence of cold gas spray parameters on the corrosion resistance of Al-Al2O3 coatings sprayed on carbon steel

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    This work describes the influence of standoff distance (SoD), and gas temperature on the morphology and corrosion resistance of Al-10%Al2O3 coatings deposited by cold gas spray (CGS) on carbon steel. The results showed that the standoff distance had little effect on the thickness and microstructure of the coating. However, a 100 °C decrease of the spraying temperature reduced the coating thickness by 300 μm. The use of electrochemical analyses and SEM images showed that all the coatings studied were able to protect the substrate during at least 1300 h of immersion, due to the dense microstructure obtained by CGS

    Effect of the outer layer of Al coatings deposited by cold gas spray on the microstructure, mechanical properties and corrosion resistance of the AA 7075-T6 aluminum alloy

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    The corrosion of AA 7075-T6 aluminum alloy is a critical issue for many industries. In this study, aluminum coatings were deposited onto AA 7075-T6 by cold gas spray and the effect of the porous outer layer on different properties of the coating, including corrosion-resistance was investigated. As-prepared and polished samples were used to study the microstructure, morphology, mechanical properties and corrosion resistance of the coating in 3.5 wt.% NaCl solution. Cross-sectional analysis showed a dense structure, low porosity (0.8%) and thickness up to 300 lm (* 100 lm for the porous outer layer and * 200 lm for the compact inner layer). The sliding wear test resulted in a volume loss of 3.2 9 10-4 mm3/Nm with an adhesive wear mechanism. The abrasive wear test showed a wear rate of 1.1 9 10-4 mm3/Nm for the asprepared coating and 0.8 9 10-4 mm3/Nm for the polished coating. The as-prepared coating pores and interparticle spacing in the outer layer were mostly responsible for the increase in wear rate. For the polished coating immersed in 3.5 wt.% NaCl solution during 900 h, the electrolyte reached some specific points of the substrate as revealed by the cross-sectional analysis. Inspection of the as-prepared coating demonstrated that the coating/substrate interface

    Five-year atmospheric corrosion of cu, cr and ni weathering steels in a wide range of environments

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    This work considers fourteen weathering steels manufactured by adding Cu, Cr and Ni alloying elements to extra mild steel. The steels were exposed for up to 5 years in different atmospheres. The atmospheric corrosion resistance of the steels was evaluated and the rust layers formed were characterised by X-ray diffraction, optical microscopy and scanning electron microscopy. The addition of Ni, particularly at 3.0 wt%, leads to a notable increase in corrosion resistance. The rusts formed contain lepidocrocite, goethite and spinel phases. X-ray diffraction also detected small amounts of kornelite (industrial atmosphere) and akaganeite (marine atmosphere)
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