Field Trials for the Empirical Characterization of the Low Voltage Grid Access Impedance From 35 kHz to 500 kHz

The access impedance of low-voltage (LV) power networks is a major factor related to the performance of the narrow-band power line communications (NB-PLCs) and, in a wider sense, to electromagnetic compatibility (EMC) performance. Up to date, there is still a lack of knowledge about the frequency-dependent access impedance for frequencies above 9 kHz and up to 500 kHz, which is the band where the NB-PLC operates. The access impedance affects the transmission of the NB-PLC signal, and it determines the propagation of the non-intentional emissions that may disturb other electrical devices, including malfunctioning or reduced lifetime of equipment. This paper presents the results of field measurements of the LV access impedance up to 500 kHz in different scenarios, with measurement locations close to end users and near transformers. The results provide useful information to analyze the characteristics of the LV access impedance, including variation with frequency, ranges of values for different frequency bands, and analysis of specific phenomena. Moreover, the results reveal a diverse frequency-dependent behavior of the access impedance in different scenarios, depending on the grid topology, the number of end users (that is, number and type of connected loads), and the type of transformation center. Overall, the results of this paper offer a better understanding of the transmission of NB-PLC signals and EMC-related phenomena.The authors would like to thank Iberdrola for the availability and the collaboration of authorized staff for carrying out the field trials

ADSORPTION ESSAYS OF PALLADIUM IN MODIFIED SILICA GEL WITH THIOURONIUM GROUPS: EXPERIMENTAL AND THEORICAL STUDIES

Indexación: Web of Science; ScieloThe silylant 3-cloropropyltriethoxysilyl was anchored over silica gel in anhydrous conditions in order to react with thiourea to obtain modified silica gel with thiouronium. The aim to obtain an inorganic support that is able to hijack metals from the VIII group such as palladium. The product was characterized by Sbet and FTIR infrared spectroscopy. For the determination of the structure in the modified silica gel NMR spectra of silicon and carbon were preformed in solid state. The coordination form of the modified silica gel to the metal was studied computationally in the context of the DFT theory, using the ADF code. This was a collaborative work with "Fundación Chile" for the recuperation of precious metals from the mining industry.http://ref.scielo.org/gk7rm

Formosolv pretreatment to fractionate Paulownia wood following a biorefinery approach: isolation and characterization of the lignin fraction

Paulownia is a rapid-growth tree with a high biomass production rate per year and low demand of water, which make it very suitable for intercropping systems, as it protects the crops from adverse climatic conditions, benefiting the harvest yields. Moreover, these characteristics make Paulownia a suitable raw material able to be fractionated in an integrated biorefinery scheme to obtain multiple products using a cascade conversion approach. Different delignification pretreatments of biomass have been purposed as a first stage of a lignocellulosic biorefinery. In this study, the formosolv delignification of Paulownia wood was investigated using a second order face-centered factorial design to assess the effects of the independent variables (concentrations of formic and hydrochloric acids and reaction time) on the fractionation of Paulownia wood. The maximum delignification achieved in this study (78.5%) was obtained under following conditions: 60 min, and 95% and 0.05% formic and hydrochloric acid, respectively. In addition, the remained solid phases were analyzed to determine their cellulose content and cooking liquors were also chemically analyzed and characterized. Finally, the recovered lignin by precipitation from formosolv liquor and the pristine lignin (milled wood lignin) in Paulownia wood were characterized and compared by the following techniques FTIR, NMR, high-performance size-exclusion chromatography (HPSEC) and TGA. This complete characterization allowed verifying the capacity of the formosolv process to act on the lignin, causing changes in its structure, which included both phenomena of depolymerization and condensation.This research was funded by MINECO (Spain) in the framework of the projects “Development of processes for the integral use of fast-growing biomass by means of the production of bioethanol and chemical products” with reference CTQ2012-30855 and “Multistage processes for the integral benefit of macroalgal and vegetal biomass” with reference CTM2015-68503-R, by Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia) through the contract ED431C 2017/62-GRC to Competitive Reference Group BV1, and by the CITACA Strategic Partnership ED431E 2018/07, programs partially funded by European Regional Development Fund (FEDER).info:eu-repo/semantics/publishedVersio

Implicación de la matriz extracelular de biofilms de Bacillus subtilis en la interacción beneficiosa con la planta

Los biofilms bacterianos están constituidos por comunidades de células unidas entre sí por una matriz extracelular polimérica. Los componentes de la matriz extracelular pueden variar dependiendo de la cepa bacteriana, pero en general se puede decir que está constituida por proteínas, exopolisacáridos y/o ácidos nucleicos. La matriz extracelular es un tejido multifuncional que contribuye a: la arquitectura final del biofilm, la regulación del flujo de nutrientes y gases dentro del biofilm, la interacción con las superficies, y la protección de las células frente a agentes tóxicos externos. Aunque son numerosos los estudios que se han centrado en el papel de la matriz en la virulencia de bacterias patógenas de humanos, este tejido polimérico puede ser igualmente importante en la interacción beneficiosa de un agente de biocontrol con la planta. Tanto para el desarrollo de la actividad de biocontrol como para la promoción del crecimiento radicular es necesaria la colonización y persistencia del microorganismo sobre la superficie de la planta, y la pregunta es hasta qué punto es importante la formación de biofilms. En este estudio trabajamos con cepas de Bacillus como agentes de control biológico (BCA) frente a enfermedades de cucurbitáceas y a su vez promotoras del crecimiento radicular (PGPR por sus siglas en inglés plant growth promoting rhizobacteria). Valiéndonos de una batería de mutantes en distintos elementos estructurales y funcionales de la matriz extracelular, estudiamos los patrones de colonización y persistencia de estas cepas en filosfera y rizosfera y evaluamos su efecto sobre la actividad PGPR. Las diferencias observadas entre algunos mutantes de matriz en cuanto a la dinámica de población y la distribución espacial en los dos nichos de estudio, así como en su actividad PGPR, apuntan a su relevancia en la ecología y funcionalidad de estos agentes de biocontrol.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Expansion for the solutions of the Bogomolny equations on the torus

We show that the solutions of the Bogomolny equations for the Abelian Higgs model on a two-dimensional torus, can be expanded in powers of a quantity epsilon measuring the departure of the area from the critical area. This allows a precise determination of the shape of the solutions for all magnetic fluxes and arbitrary position of the Higgs field zeroes. The expansion is carried out to 51 orders for a couple of representative cases, including the unit flux case. We analyse the behaviour of the expansion in the limit of large areas, in which case the solutions approach those on the plane. Our results suggest convergence all the way up to infinite area.Comment: 26 pages, 8 figures, slightly revised version as published in JHE

Identification of Genes Responsive to Solar Simulated UV Radiation in Human Monocyte-Derived Dendritic Cells

Ultraviolet (UV) irradiation has profound effects on the skin and the systemic immune system. Several effects of UV radiation on Dendritic cells (DCs) functions have been described. However, gene expression changes induced by UV radiation in DCs have not been addressed before. In this report, we irradiated human monocyte-derived DCs with solar-simulated UVA/UVB and analyzed regulated genes on human whole genome arrays. Results were validated by RT-PCR and further analyzed by Gene Set Enrichment Analysis (GSEA). Solar-simulated UV radiation up-regulated expression of genes involved in cellular stress and inflammation, and down-regulated genes involved in chemotaxis, vesicular transport and RNA processing. Twenty four genes were selected for comparison by RT-PCR with similarly treated human primary keratinocytes and human melanocytes. Several genes involved in the regulation of the immune response were differentially regulated in UVA/UVB irradiated human monocyte-derived DCs, such as protein tyrosine phosphatase, receptor type E (PTPRE), thrombospondin-1 (THBS1), inducible costimulator ligand (ICOSL), galectins, Src-like adapter protein (SLA), IL-10 and CCR7. These results indicate that UV-exposure triggers the regulation of a complex gene repertoire involved in human-DC–mediated immune responses

DICOM y sistema de registro en radiología: propuestas de mejora

La radiología y radiofísica han sabido dar un paso diferencial respecto otras ramas de conocimiento definiendo, prácticamente desde la introducción de la tomografía computerizada, el estándar de almacenamiento de información DICOM (Digital Imaging and Communication in Medicine) que facilita la accesibilidad a un conjunto común y estructurado de datos a nivel mundial que no existe en ningún otro ámbito. La información contenida en los sistemas de registro dosimétricos son clave a la hora de analizar y obtener resultados fiables que deben permitir reducir la incertidumbre estadística y posibilitar la aplicación de metodologías y técnicas de tratamiento de la información como la minería de datos y el análisis de BigData con inteligencia artificial. En la actualidad DICOM permite la transmisión, tratamiento e impresión de archivos de imágenes biomédicas con un informe completo, incluyendo información del paciente, del estudio realizado e incluso del equipo radiológico y magnitudes dosimétricas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech