1,588 research outputs found

    Metal Accumulation by Jatropha curcas L. Adult Plants Grown on Heavy Metal-Contaminated Soil

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    Jatropha curcas has the ability to phytoextract high amounts of heavy metals during its first months just after seeding. Notwithstanding, there is scarce information about metal uptake by adult J. curcas plants. To shed light on this issue, 4-year-old J. curcas L. plants were planted in a soil mixture of peat moss and mining soil (high metals content), and the biomass growth and metal absorption during 90 days were compared with those of plants growing in peat moss. The main metal found in the mining soil was Fe (31985 mg kg-1) along with high amounts of As (23717 mg kg-1). After the 90-day phytoremediation, the plant removed 29% of Fe and 44% of As from the soil mixture. Results revealed that J. curcas L. translocated high amounts of metals to its aerial parts, so that translocation factors were much higher than 1. Because of the high translocation and bioaccumulation factors obtained, J. curcas L. can be regarded as a hyperaccumulator plant. Despite the great capacity of J. curcas L. to phytoremediate heavy-metal-contaminated soils, the main drawback is the subsequent handling of the metal-contaminated biomass, although some potential applications have been recently highlighted for this biomass.University of Seville (VIPPIT-2019-I.5

    Influence of glycerol addition on the droplet size distribution, mean diameters and physical stability of ecological O/W emulsions processed with Microfluidizer technology

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    The aim of this work was to investigate the influence of the pressure ( 0 psi and 15000 psi) and the number of passes (0,1,2 and 3) through a high pressure homogenizer with Microfluidizer technology on the droplet size distribution, mean diameters and physical stability of ecological O/W emulsions. The results with an emulsion formulated with 50 wt% of glycerol in the continuous phase are compared. As dispersed phase a 30 wt% mixture of green solvents, N,N-dimethyldecanamide and α-pinene with a 75/25 mass ratio was used. In addition, an ecological surfactant derived from coconut oil, HLB = 13.El objetivo de este trabajo ha consistido en investigar cómo influye la presión (0 y 15000 psi) y el número de pasadas (1, 2 y 3) a través de un homogeneizador de alta presión con tecnología Microfluidizer sobre la distribución de tamaños de gota, diámetros medios y estabilidad física de una emulsión ecológica O/W. Se comparan los resultados con la emulsión formulada con un 50% en peso de glicerol en el medio continuo. Como fase dispersa se utiliza un 30% en peso de una mezcla de disolventes verdes, N,N-dimetildecanamida y α-pineno, en una relación en masa de 75/25. Adicionalmente se emplea un tensioactivo ecológico derivado de aceite de coco, de HLB 13.Ministerio de Economía y Competitividad de España-CTQ2015-70700-PComisión Europea (Programa FEDER

    Seguridad en Internet

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    El presente documento describe los problemas que enfrenta todo usuario en la actualidad con el manejo de la información libre a través del Internet. Específicamente el robo de información. Los datos, información o archivos que son enviados de una PC a otra pueden ser interceptados y leídos por personas no autorizadas. Aquí se menciona la necesidad de diseñar mejores políticas, controles, procedimientos y recomendaciones a los administradores de redes y empresas en general. También se expone el caso de los software dañinos o virus desde sus orígenes hasta las medidas que se pueden tomar para evitarlos. Describe los servicios y mecanismos de seguridad que se deben tomar en cuenta para mejorar la seguridad en la comunicación entre usuarios. Detalla el uso de aplicaciones de correos seguros. Menciona las razones que hace a la aplicación PGP ser la más generalizada y el uso que hace de los diferentes algoritmos para ofrecer mayor seguridad. Resalta la importancia del uso de firmas digitales en los mensajes para protegerlos. Se diseñó una aplicación la cual hace uso del método o cifrado de Vigenere que encripta / desencripta archivos y cadenas de texto

    Evaluation of the Uncertainty of Surface Temperature Measurements in Photovoltaic Modules in Outdoor Operation

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    Faults in photovoltaic modules in operation can lead to power losses. By determining the module surface temperature, hot spots that can potentially cause this power loss can be detected. Temperature measurement by radiation allows a complete, reliable, and fast qualitative determination of hot spots on PV modules in outdoor operation. However, to obtain quantitative values, it is necessary to consider multiple factors: emissivity, reflected radiation, wind speed, intensity, shading, etc. Temperature quantitative measurement evaluation by contact is more studied, although by this technique it is impossible to examine the temperature of the entire module to detect hot spots because it is a point measurement and due to shading caused by the measurement probe on the surface. In this work, a method of temperature measurement by radiation is described, evaluating the uncertainty components, and a comparison is made with temperature measurement by contact on the module rear side points where module heating has been detected, also evaluating the uncertainty components. This comparison of both methods and uncertainty determination allows establishing a methodology in quantitative temperature measurement by radiation in photovoltaic modules in outdoor operation

    Strategy Based on Two Stages for IR Thermographic Inspections of Photovoltaic Plants

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    Aerial infrared (IR) thermography has been implemented in recent years, proving to be a powerful and versatile technique for performing maintenance at photovoltaic (PV) plants. Its application speed and reliability using unmanned aerial vehicles (UAVs) or drones make it extremely interesting at large PV plants, due to the associated savings in time and costs. Ground-level thermographic inspection is slower and more costly to apply, although it does provide higher optical resolution, due to being conducted closer to the PV modules being inspected. Both techniques used in combination can improve the diagnosis. An IR thermography inspection strategy is proposed for PV plants based on two stages. The first stage of the inspection is aerial, enabling thermal faults to be detected and located quickly and reliably. The second stage of the inspection is done on the ground and applied only to the most relevant incidents revealed in the first stage. This inspection strategy was applied to a 100 kW PV plant, with an improved diagnosis verified via this procedure, as the ground-level inspection detects one-off thermal incidents from objects creating shade and from solar reflections. For PV modules with open circuits or open substrings, the use of one technique or another is immaterial

    Valoración de la experiencia piloto de adaptación al ECTS en la asignatura Gestión Financiera en el Sector Turístico I

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    En este trabajo exponemos nuestra propuesta de plan docente adaptado al sistema europeo de créditos ECTS y la valoración de la experiencia piloto de la Diplomatura en Turismo de la Escuela Universitaria de Estudios Empresariales de la Universidad de Sevilla, tanto por parte de las profesoras que impartimos la asignatura como de los alumnos, al objeto de determinar el grado de satisfacción de las necesidades y expectativas de aprendizaje del nuevo modelo docente.In this work we expose our educational plan adapted to the European Credit Transfer System, ECTS, and the evaluation of the pilot experience of the Diploma in Tourism in the Business Studies University School (University of Seville), so much on the part of the teachers that we give the subject as of the students, in order to determine the degree of satisfaction of the needs and expectations of learning of the new educational model

    Seasonal changes in antioxidative/oxidative profile of mining and non-mining populations of Syrian beancaper as determined by soil conditions

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    Soil pollution by heavy metals/metalloids (HMMs) is a problem worldwide. To prevent dispersion of contaminated particles by erosion, the maintenance of a vegetative cover is needed. Successful plant establishment in multi-polluted soils can be hampered not only by HMM toxicities, but also by soil nutrient deficiencies and the co-occurrence of abiotic stresses. Some plant species are able to thrive under these multi-stress scenarios often linked to marked fluctuations in environmental factors. This study aimed to investigate the metabolic adjustments involved in Zygophyllum fabago acclimative responses to conditions prevailing in HMM-enriched mine-tailings piles, during Mediterranean spring and summer. To this end, fully expanded leaves, and rhizosphere soil, of three contrasting mining and non-mining populations of Z. fabago grown spontaneously in south-eastern Spain were sampled in two consecutive years. Approximately 50 biochemical, physiological and edaphic parameters were examined, including leaf redox components, primary and secondary metabolites, endogenous levels of salicylic acid, and physicochemical properties of soil (fertility parameters and total concentration of HMMs). Multivariate data analysis showed a clear distinction in antioxidative/oxidative profiles between and within the populations studied. Levels of chlorophylls, proteins and proline characterized control plants whereas antioxidant capacity and C- and S-based antioxidant compounds were biomarkers of mining plants. Seasonal variations were characterized by higher levels of alkaloids and PAL and soluble peroxidase activities in summer, and by soluble sugars and hydroxycinnamic acids in spring irrespective of the population considered. Although the antioxidant systems are subjected to seasonal variations, the way and the intensity with which every population changes its antioxidative/oxidative profile seem to be determined by soil conditions. In short, Z. fabago displays a high physiological plasticity that allow it to successfully shift its metabolism to withstand the multiple stresses that plants must cope with in mine tailings piles under Mediterranean climatic conditions.This work was supported by the Ministerio de Ciencia e Innovación [grant number CTM2011-23958]; Ministerio de Ciencia y Tecnología [grant number CGL2006-11569]; and Fundación Séneca [grant number FB/23/FS/02]. AL-O holds a grant from the Ministerio de Educación Cultura y Deporte [grant number AP2012-2559]. Part of this work was carried out at the Instituto de Biotecnología Vegetal, UPCT

    Perceived parenting styles and adjustment during emerging adulthood: a cross-national perspective

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    The aim of the present study is to determine whether the influence of parenting style on children’s wellbeing is sustained during emerging adulthood. This is a stage in which young people, despite feeling themselves to be adults, often remain in the family home and continue to be financially dependent on their parents. Moreover, since parents’ beliefs, attitudes and behaviors are constructed and interpreted within their cultural milieu, the study also aims to explore the situation in Spain (SP) and Portugal (PT). Those two Southern Europe countries are representative of what is known as the “family welfare regime”, in which the family acts as the main provider of care and security not only during childhood, but also during emerging adulthood. Thus, the present study examines, from a cross-cultural perspective, the relationship between perceived parenting styles and psychological adjustment among a sample of 1047 emerging adults from Spain and Portugal. The results reveal that the most beneficial styles during this stage are the authoritative and permissive ones, with the authoritarian style being more closely related to psychological distress. The study highlights intercultural similarities and the positive role played by more symmetrical relationships in the adjustment of emerging adults in both countries.Ministerio de Economía y Competitividad EDU2013-45687-RMinisterio de Economía y Competitividad RTI2018-097405-B-I0
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