A simple spatiotemporal evolution model of a transmission power grid

In this paper, we present a model for the spatial and temporal evolution of a particularly large human-made network: the 400-kV French transmission power grid. This is based on 1) an attachment procedure that diminishes the connection probability between two nodes as the network grows and 2) a coupled cost function characterizing the available budget at every time step. Two differentiated and consecutive processes can be distinguished: a first global space-filling process and a secondary local meshing process that increases connectivity at a local level. Results show that even without power system engineering design constraints (i.e., population and energy demand), the evolution of a transmission network can be remarkably explained by means of a simple attachment procedure. Given a distribution of resources and a time span, the model can also be used to generate the probability distribution of cable lengths at every time step, thus facilitating network planning. Implications for network's fragility are suggested as a starting point for new design perspectives in this kind of infrastructures.Peer ReviewedPostprint (author's final draft

Escoletes de Menorca. Què ho ha fet i ho fa possible?

L’objectiu d’aquest article és descriure i analitzar de forma sintètica les principals característiques del model educatiu de l’escola infantil de primer cicle menorquina, que abasta dels zero fi ns als tres anys, i que coneixem amb el diminutiu d’«escoleta». Però abans d’entrar en l’anatomia i la fi siologia de l’escoleta menorquina i el seu entorn, és necessari fer una breu contextualització sociopolítica i sociocultural per comprendre’n més bé els antecedents i la trajectòria.El objetivo de este artículo es describir y analizar de forma sintética las principales características del modelo educativo de la escuela infantil de primer ciclo menorquina, que abarca desde los cero hasta los tres años, y que conocemos con el disminutivo de «escoleta». Pero antes de entrar en la anatomía y la fi siología de la escuela menorquina de educación infantil y de su entorno, es necesario hacer una breve contextualización sociopolítica y sociocultural para comprender mejor sus antecedentes y su trayectoria

Digitalización del fondo histórico de la Real Escuela de Avicultura

La Facultad de Veterinaria de la Universitat Autònoma de Barcelona (UAB) y la Real Escuela de Avicultura de Arenys de Mar (REA) han firmado el 2011 un convenio de colaboración en materia de digitalización, preservación y informatización del fondo documental de esta última institución centenaria. La REA cuenta con una amplia tradición en la investigación de los sectores avícola y cunícola en España y el mundo desde finales del siglo. La UAB, a través del servicio de bibliotecas e informática, cuenta con una importante infraestructura tecnológica que le permite satisfacer las necesidades de conservación y difusión del legado documental que atesora la REA

Mapas conceptuales y mentales en historia de la veterinaria : estudio de dos casos prácticos

Los mapas conceptuales (concept maps) permiten la representación gráfica de conceptos así como las relaciones existentes entre ellos. Están formados por términos que se explicitan en etiquetas, palabras de enlace que se utilizan para establecer las relaciones entre las diferentes ideas, y proposiciones que unen dos o más términos, las cuales junto con las palabras que los enlazan forman una unidad semántica

Los archivos privados al servicio de la investigación histórica. Casos Roca y Camps

El pasado año 2012 la Asociació Catalana d'Història Veterinària (ACHV) recibió la donación de los fondos de archivo de Jaume Roca Torras, fallecido el mismo año, a través de la familia y la Real Academia de Ciencias Veterinarias de Catalunya, depositaria del mismo, y el archivo de Jaume Camps Rabadá, presidente de la ACHV, contando con su complicidad. Los documentos incluidos en dichos archivos, han sido tratados siguiendo procesos estandarizados de selección, organización, clasificación e inventario1, y promoviendo la digitalización de aquellos que legalmente cumplieran los requisitos de propiedad intelectual. Dicha documentación digitalizada, se encuentra disponible a través de los portales que hemos creado en el repositorio institucional de documentos "DDD" de la UAB para ambos archivos.Congreso Iberoamericano de Historia de la Veterinaria. Madrid, 10è : 201

Anàlisi i control de cianurs i productes relacionats presents en aigües residuals i dissolucions de processos industrials mitjançant electroforesi capil.lar

Esta tesis consiste en la aplicación de la electroforesis capilar (CE) a la separación y cuantificación de especies cianuradas y al estudio del comportamiento de estas especies y de su destino final. Como material de estudio se han seleccionado distintos procesos industriales (lixiviación de minerales y arenas auriferas, disoluciones de proceso en industrias de recubrimientos electrolíticos, lixiviación intensiva en autoclave de convertidores de automóvil) donde los cianuros tienen aplicación. En la primera parte de la tesis se ha realizado un estudio detallado de las características de la técnica CE, y posteriormente se ha optimizado una metodología para aplicarla a los distintos problemas que se recogen en el resto de la memoria. La segunda parte de la tesis se ha dedicado a la aplicación de la ce al estudio de la lixiviación con NaCN de los metales preciosos y estratégicos presentes en minerales auriferos (Au, Ag) y en convertidores de automóviles (PT, PD, RH), obteniendo finalmente un método analítico capaz de ser utilizado para el seguimiento de este tipo de procesos. En la tercera parte de la tesis se ha realizado la determinación del cianuro libre, del débilmente ligado y del total en aguas procedentes de la industria de los recubrimientos electrolíticos y en disoluciones de cianuros oxidadas con hipoclorito, que es el método mas extendido para tratar las aguas industriales. Para analizar estas formas de cianuros, se han planteado dos soluciones, basadas en la detección indirecta y en la derivatización.La problemática de la detección del cianuro libre (CN- y HCN (aq)) y de especies relacionadas (CNO-, SCN-, NO3, CI-, SO42- y CIO-) resuelto con la utilización de la fluorescencia indirecta con un detector prototipo con fuente láser.La determinación de cianuros en muestras reales de disoluciones de recubrimientos electrolíticos se ha conseguido mediante su derivatizacion a NI(CN)42- utilizando una disolución de NI(II)-NH3

Environmental risk assessment of silver nanoparticles in 2 aquatic ecosystems using fuzzy logic

The rapid development of nanotechnology has stimulated the use of silver nanoparticles (AgNPs) in various fields that leads to their presence in different ecosystem compartments, in particular aquatic ecosystems. Several studies have shown that a variety of living organisms are affected by AgNPs. Therefore, a methodology to assess the risk of AgNPs for aquatic ecosystems was developed. The methodology is based on fuzzy logic, a proven method for dealing with variables with an associated uncertainty, as is the case with many variables related to AgNPs. After a careful literature search, a selection of relevant variables was carried out and the fuzzy model was designed. From inputs such as AgNPs’ size, shape, and coating, it is possible to determine their level of toxicity which, together with their level of concentration, are sufficient to create a risk assessment. Two case studies to assess this methodology are presented, one involving continuous effluent from a wastewater treatment plant and the second involving an accidental spill. The results showed that the accidental spills have a higher risk than WWTP release, with the combination of Plates–BPEI being the most toxic one. This approach can be adapted to different situations and types of nanoparticles, making it highly useful for both stakeholders and decision makersPostprint (published version

Potential Use of Precipitates from Acid Mine Drainage (AMD) as Arsenic Adsorbents

The role of precipitates from acid mine drainage (AMD) in arsenic removal in water is a process to be investigated in more detail. The present study is focused on the potential use of two AMD precipitates using oxidation and Ca(OH)2 (OxPFe1) or CaCO3 (OxPFe2) as As(V) adsorbents and the comparison of their performance with two commercial adsorbents (nanohematite and Bayoxide®). The AMD's supernatants and precipitates were characterized using several techniques and assessed with theoretical speciation and mass balance methods. Gypsum was identified by XRD and assessed as the main component of the precipitates. Amorphous iron hydroxide was assessed as the second component (22% in mass), and jurbanite or aluminum hydroxide were present in the third likely phase. The equilibrium adsorption of As(V) in water at a pH between 4 and 6 was tested with the four adsorbents, and the Langmuir model correlated well. The maximum adsorption capacity (qmax) had the highest value for OxPFe1 and the lowest value for nanohematite (that could be explained in terms of the adsorbent surface speciation). The two precipitates have limited application to the adsorption of very low concentrations of arsenic because they have a binding constant (b) lower than the commercial adsorbents and could release a small amount of the arsenic contained in the precipitate

Environmental risk assessment of silver nanoparticles in aquatic ecosystems using fuzzy logic

The rapid development of nanotechnology has stimulated the use of silver nanoparticles (AgNPs) in various fields that leads to their presence in different ecosystem compartments, in particular aquatic ecosystems. Several studies have shown that a variety of living organisms are affected by AgNPs. Therefore, a methodology to assess the risk of AgNPs for aquatic ecosystems was developed. The methodology is based on fuzzy logic, a proven method for dealing with variables with an associated uncertainty, as is the case with many variables related to AgNPs. After a careful literature search, a selection of relevant variables was carried out and the fuzzy model was designed. From inputs such as AgNPs’ size, shape, and coating, it is possible to determine their level of toxicity which, together with their level of concentration, are sufficient to create a risk assessment. Two case studies to assess this methodology are presented, one involving continuous effluent from a wastewater treatment plant and the second involving an accidental spill. The results showed that the accidental spills have a higher risk than WWTP release, with the combination of Plates–BPEI being the most toxic one. This approach can be adapted to different situations and types of nanoparticles, making it highly useful for both stakeholders and decision makers.This research was funded by the Spanish Ministry of Science, Innovation and Universitiesand Agencia Estatal de Investigación/European Regional Development Plan (grant CGL2017-87216-C4-3-R). Authors want to thank Fundación Carolina and Universidad Tecnológica del Chocófor thePhD research grant given to Mr. Ramírez.Peer ReviewedPostprint (published version

Functionalization of Screen-Printed Electrodes with Grape Stalk Waste Extract-Assisted Synthesized Silver and Gold Nanoparticles: Perspectives of electrocatalytically Enhanced Determination of Uranyl Ion and Other Heavy Metals Ions

Recently, nanotechnology and nanoparticles (NPs) such as AgNPs and AuNPs have become important in analytical chemistry due to their great potential to improve the performance of electrochemical sensors. In this work, Ag and Au nanoparticles have been synthesized using a green route in which a grape stalk waste extract is used as a reducing agent to obtain metallic nanoparticles. These NPs were used to customize the surface of commercial screen-printed electrodes (SPCNFEs). The spin-coating method was used to modify commercial SPCNFEs under a nitrogen atmosphere. The resulting electrodes were used in a determination study of Cd(II), Pb(II), and U(VI) with differential pulse anodic stripping voltammetry (DPASV). The customized green AgNPs and AuNPs electrodes presented higher sensitivity and electroanalytical performance than the nonmodified SPCNFE. The results showed that the best analytical parameters were obtained with the green, silver nanoparticle SPCNFEs, with a LOD of 0.12 µg L−1 for Pb(II), which is a lower value compared to the most restrictive regulation guidelines. Additionally, the U(VI) ion was successfully determined using the developed G-AgNPs-SPCNFE in spiked tap water, showing comparable results with the ICP-MS techniqu