Modeling dispersion of partial discharges due to propagation velocity variation in power cables

Existing models for partial discharge (PD) propagation based on a single attenuation constant are unable to explain how each frequency component travels with a different propagation velocity. This paper proposes a new model based on a complex propagation term whose real component does not depend on the frequency ($f$), and whose imaginary part is modeled with a second order polynomial in $f$. The proposed model explains how the PD is attenuated, delayed, and dispersed due to the fact that each frequency component is differently delayed. A closed-form expression is proposed for the PD peak value and width, and a method to derive the model parameters from a reference model existing in the bibliography. Simulation results show that the peak value and width of the propagated PD pulse are similar to those obtained with the proposed model. Additionally, the proposed model provides the velocity of each PD frequency component, which is crucial to get an accurate estimation of the PD source location. The parameters of the proposed model have been estimated using a vector network analyzer for a XLPE cable. These results have been compared to the measurement obtained in a medium voltage test bench where intentionally induced PDs have been captured and processed, confirming the results of attenuation, delay and dispersion predicted by the proposed model

Policy labs in Europe: political innovation, structure and content analysis on Twitter

Recent years have seen a veritable boom in the creation of policy labs. These institution-based innvation laboratories aim to open up the processes of public policy design to the social stakeholders involved. In 2016, the European Union Policy Lab commissioned a report that identified 64 such laboratories in Europe. In the present study, we use network analysis to reveal the structure of the relationships between the 42 of these labs that have a presence on Twitter. We then conduct a content analysis of their tweets to identify the topics of interest. Our results describe a fragmented, country-based network and the principal concepts and key issues addressed by these institutions

Plan de negocio: “Ángel guardián”

48 Páginas.Ángel guardián nace desde los insights de la población de Bogotá ante la realidad del paseo millonario, tras realizar una investigación de mercado que evidencio la hipótesis planteada, comenzamos a basarnos en el estudio del entorno y la competencia. Esto nos acercó a un análisis profundo de las fortalezas, debilidades, oportunidades y amenazas para Ángel Guardián. Partiendo de esa base realizamos las proyecciones financieras y encontramos que además de cumplir con el objetivo principal ángel guardián es un negocio rentable

Desarrollo de una escala de riesgo anticolinérgico específica para pacientes crónicos en España

Introducción: Los fármacos anticolinérgicos son actualmente muy utilizados para el tratamiento de diversas enfermedades, sin embargo, sus frecuentes efectos adversos hacen que haya que tener un especial cuidado a la hora de recetar este tipo de medicamentos, especialmente en pacientes mayores, crónicos y polimedicados, ya que por sus características son los más vulnerables a sufrir este tipo de efectos secundarios. Las escalas de riesgo anticolinérgico sirven de ayuda para estimar el riesgo que tiene un paciente de sufrir estos efectos adversos, aunque hay que destacar que entre las distintas escalas existen importantes diferencias. Objetivos: El objetivo principal es desarrollar una escala de riesgo anticolinérgico española. Metodología: Se realizó una revisión bibliográfica a partir de búsquedas en PubMed utilizando una serie de palabras clave. Para seleccionar los artículos a incluir se aplicaron unos criterios de inclusión. Posteriormente, se elaboró la escala española utilizando un algoritmo para seleccionar los fármacos a incluir. Resultados: Tras la revisión bibliográfica fueron seleccionados 12 artículos, en los cuales se encontraron 8 nuevas escalas a partir de las cuales se elaboró la escala española. La escala de riesgo anticolinérgico española elaborada cuenta con 207 fármacos y sigue la metodología de la DBI. Discusión: Actualmente no existe ninguna escala estandarizada para medir el riesgo anticolinérgico y se ha visto que sería interesante contar con escalas adaptadas a los diferentes países, ya que no todos los países tienen comercializados los mismos fármacos. Conclusiones: Las escalas de riesgo anticolinérgico son una de las mejores herramientas para controlar la carga anticolinérgica en los pacientes más vulnerables, lo que hace que sea de especial interés contar con una escala anticolinérgica adaptada a nuestro país.Universidad de Sevilla. Grado en Farmaci

Aptamers: Future Pharmaceutical Drugs

In vitro selection strategies are powerful tools for the identification of nucleic acids with unsuspected activities. Their successful application during last two decades has positioned these technologies among those most promising for the development of therapeutic and diagnostic agents. Aptamers are DNA or RNA molecules with special conformational features, able to efficiently bind to a target molecule. They are obtained by SELEX, a particular in vitro selection strategy, and have found utility during last years as a novel class of pharmaceuticals compounds. This review summarizes the progress made in the use of aptamers as therapeutic agents, paying special attention to those examples that have concluded in pharmacological formulations currently included in preclinical and clinical trials.The work in the group of A.B.-H. is funded by grant BFU2009-08137 from the Spanish Ministry of Science and Innovation; grant CTS-5077 from the Junta de Andalucía; and by FEDER funds from the EU.Peer Reviewe

Mapping the backbone of the Humanities through the eyes of Wikipedia

The present study aims to establish a valid method by which to apply the theory of co-citations to Wikipedia article references and, subsequently, to map these relationships between scientific papers. This theory, originally applied to scientific literature, will be transferred to the digital environment of collective knowledge generation. To this end, a dataset containing Wikipedia references collected from Altmetric and Scopus’ Journal Metrics journals has been used. The articles have been categorized according to the disciplines and specialties established in the All Science Journal Classification (ASJC). They have also been grouped by journal of publication. A set of articles in the Humanities, comprising 25 555 Wikipedia articles with 41 655 references to 32 245 resources, has been selected. Finally, a descriptive statistical study has been conducted and co-citations have been mapped using networks and indicators of degree and betweenness centralit

Independent publishers and social networks in the 21st century: the balance of power in the transatlantic Spanish-language book market

The present paper uses Twitter to analyze the current state of the worldwide, Spanish-language, independent publishing market. The main purposes are to determine whether certain Latin American Spanish-language independent publishers function as gatekeepers of World Literature and to analyze the geopolitical structure of this global market, addressing both the Europe-America dialectic and neocolonial practices. After selecting the sample of publishers, we conducted a search for their Twitter profiles and located 131; we then downloaded data from the corresponding Twitter APIs. Finally, we applied social network analysis to study the presence of and interaction between our sample of independent publishers on this social media. Our results provide data-based evidence supporting the hypothesis of some literary critics who suggest that in Latin America, certain publishers act as gatekeepers to the mainstream book market. Therefore, Twitter could be considered a valid source of information to address the independent book market in Spanish. By extension, this approach could be applied to other cultural industries in which small and medium-sized agents develop a digital presence in social media. This paper combines social network analysis and literary criticism to provide new evidence about the Spanish-language book market. It helps validate the aforementioned hypothesis, proposed by literary critics, and opens up new paths along which to pursue an interpretative, comparative analysis

Who influences policy labs in the European Union? A social network approach

The growing importance of public innovation has been manifested through the creation of policy labs: spaces for policy experimentation and innovation that work for or within a government entity. The rise of this phenomenon in Europe was evidenced by the creation of a policy lab by the European Commission (EC) in 2016 and the publication by the EC of a report identifying policy labs and their influencers in Europe. Public innovation is increasingly based on national and international networks, giving rise to complex ecosystems involving participation by multiple actors from countries with different administrative approaches. Our study uses social network analysis of these labs’ Twitter profile data to map the European Union’s (EU) public innovation ecosystem and identify the major influencers. Policy labs and their influencers are analyzed by administration style by using a large geographical database. The results reveal a complex global network of influencers and a strong predominance of the Anglo-Saxon administration style. From an EU perspective, our systematic analysis of influence is particularly important in the post-Brexit context, helping to foster a genuine public innovation ecosystem that is both autonomous and interconnected with the aim of facing challenges such as the Sustainable Development Agenda and COVID-19 crisis recovery.Spanish Ministry of Science and Innovation grant numbers PID2019-109127RB-I00/SRA/10.13039/501100011033PID2020-117007RA-I00Regional Government of Andalusia Junta de Andalucía grant number A-SEJ-638-UGR20FPU Grant (FPU18/05835) from the Spanish Ministry of Universitie

In silico logistic model for table olive related microorganisms as a function of sodium metabisulphite, cinnamaldehyde, pH, and Type of acidifying agent

A probabilistic/logistic model, based on binary data (growth/no growth), was used to assess the effects of sodium metabisulphite (SM) and cinnamaldehyde (CIN; 0-1000 mg/L) against the main microbial groups found in table olive environment [lactic acid bacteria (LAB), yeasts, and Enterobacteriaceae], according to pH (range 3.5-5.0), and type of acidifying agent (HCl or pyruvic acid). The inhibitory effect of SM depended on the pH while that of CIN was scarcely influenced by it (except for LAB). LAB were more sensitive to SM, while yeasts were to CIN. The use of pyruvic acid for correction of pH always produced a reduction (compared to HCl) of the inhibitory power of both preservatives. The in silico models for HCl showed that, at pH 4.0, and growth probability 0.01, the LAB population might be inhibited by the presence in the medium of 150 mg/L SM or 1000 mg/L CIN, while in the case of yeasts, 450 mg/L SM, or 150 mg/L CIN are required. No growth of Enterobacteriaceae was observed at this (or lower) pH level. The results obtained may contribute to the stabilization of non-thermally treated table olive packaging.This research has received funding from INTERACEITUNA (Organización Interprofesional de la Aceituna de Mesa, Spain) and the Junta de Andalucía. FNAL thanks to the Spanish Government and CSIC for his Ramón y Cajal postdoctoral research contract, while VR thanks the AgriFood Campus of International Excellence (ceiA3), Bank of Santander, Spanish Government and “Aloreña de Málaga” Olive Manufacturing Association for her pre-doctoral fellowship (training and formation program of Ph.D. in companies).Peer Reviewe

Time domain analysis of partial discharges envelope in medium voltage XLPE cables

Partial discharge (PD) analysis has been widely used to detect premature degradation of power cables. Although there are recognized techniques for PD analysis, there is still lack of knowledge about measuring and modeling this phenomenon. This paper proposes a new model based on time domain parameters of the PD signal envelope. The proposed variables (time duration, and rising and falling slopes of the envelopes), together with conventional PD analyses focused on PD amplitude and phase resolved patterns, will provide a better understanding of this phenomenon. Based on this model, a new technique to reshape the PD signal envelope is also proposed that compensates the negative effect of dispersion in the location techniques that estimate the time of arrival (TOA). Experimental results were obtained in the lab, where a power cable has been artificially damaged in order to produce PD. To this end, a specific PD on-line acquisition system has been developed. In the first set of experiments, we illustrate how the cable attenuates and disperses the PD signal envelope. In the second one, we show how the proposed variables are useful to distinguish among different types of PD sources. Finally, an accurate estimation of the PD source location is achieved by measuring the time of arrival of the PD signal envelopes at both cable ends, and reshaping one of the signals captured. This technique improves the accuracy of the estimated location of the PD sources, both in simulation and in experimental results