Análisis de sensibilidad y estabilidad de pequeña señal en convertidores seguidores de red

This article presents a small-signal study, based on a sensitivity analysis, of a voltage source converter (VSC) operating as a grid-following device. This type of operation is standard for integrating distributed energy resources directly into a primary grid without considering the control over specific variables (e.g., voltage and frequency), thus maximizing the amount of injected active power. The present study adopted the classical vector-oriented control based on the linearization method of the averaged model; hence, this analysis is limited to linear controls. The main objective of this study is to evaluate how each controller parameter influences the system’s stability. To conduct the sensitivity analysis, an averaged model in the dq reference frame of the VSC was employed to describe the system dynamics in the equivalent state-space model. Afterward, the stability was analyzed through a sensitivity analysis of the eigenvalues of the corresponding state matrix. The numerical results demonstrate that the main problems for the stability of VSCs operating as grid-following converters are threefold: a high value of the filter inductance, a non-ideal impedance that appears depending on the connection point, and poor coordination of the parameters of the Kp controllers. These results are compared to a simple bifurcation analysis of the state matrix, which consists of a diagram that describes the variation in eigenvalues when a parameter changes, thus proving their validity.  El presente artículo presenta un estudio de pequeña señal, basado en el análisis de sensibilidad, del convertidor Voltage Source Converter (VSC) operando como dispositivo de seguimiento de red. Este tipo de operación es común para la integración de recursos energéticos distribuidos directamente a la red primaria sin considerar el control sobre variables específicas como la tensión o la frecuencia, maximizando así la cantidad de potencia activa inyectada. El presente estudio adopta el clásico Control Vectorial Orientado basado en la linealización del modelo promediado, por tanto, este análisis es limitado a controles lineales. El objetivo principal de esta investigación consistió en evaluar cómo influye cada parámetro del controlador en la estabilidad del sistema. Con el fin de realizar el análisis de sensibilidad, se empleó un modelo medio en el marco de referencia dq del VSC para describir la dinámica del sistema en el espacio de estados equivalentes; posteriormente, se buscó la estabilidad mediante un análisis de sensibilidad de los valores propios de la matriz de estado correspondiente, cuyos resultados numéricos demostraron que los principales problemas para la estabilidad de los VSC que operan como convertidores de seguimiento son tres: un valor elevado de la inductancia del filtro, la presencia de una impedancia no ideal que aparece en función del punto de conexión, y una mala coordinación de los parámetros de los controladores Kp. Estos resultados se han comparado con un simple análisis de bifurcación de la matriz de estado, que consiste en un gráfico que describe el movimiento de los valores propios cuando cambia un parámetro, corroborando así su validez

Apuntes de tecnología de fabricación de circuitos integrados monolíticos, de capa fina y de capa gruesa

Apuntes creados como apoyo a la asignatura "Tecnología de fabricación de circuitos integrados monolíticos", impartida en el curso 1974-1975

Apuntes de tecnología de fabricación de circuitos integrados monolíticos, de capa fina y de capa gruesa

Apuntes creados como apoyo a la asignatura "Tecnología de fabricación de circuitos integrados monolíticos", impartida en el curso 1974-1975

Multi-dimensional barrier identification for wind farm repowering in Spain through an expert judgment approach

.Spain was one of the pioneers in the deployment of wind energy systems worldwide and thus since 2014 has a potential for repowering that reaches between 3.3 and 8.7 GW in 2021 (12%–32% of its current installed wind capacity). However, despite the technical and economic advantages, we have observed little interest from promoters in the repowering of already amortized wind farms. The aim of the proposed study is to depict the background framework of barriers for repowering wind farms, which is specially affecting to Spain, but that can also extend to other EU countries. Therefore, we conducted a systematic survey study with academics, promoters, financial experts, manufacturers, operators, maintainers and policymakers to identify and understand the existing real and practical barriers. As a result, we have identified 34 major barriers covering five categories: technical issues, economics, environmental considerations, social concerns, and regulatory and administrative hurdles. We then asked the experts to rate these barriers based on their impact or relevance. We found that the experts agree that regulatory and administrative barriers have the maximum impact, while economic, environmental and technical barriers have only a mid-high impact. Therefore, we can conclude that, in general, the Administration must develop a concise and stable regulatory framework for all RES, especially for repowering projects, and carry out a review of both the technical requirements and the incentives schemes, with a focus on energy efficiency.S

Wind energy planning for a sustainable transition to a decarbonized generation scenario based on the opportunity cost of the wind energy: Spanish Iberian Peninsula as case study

[EN] Most countries in Europe are going under a significant transformation process from carbonized power energy sources to renewable and sustainable ones to feed their increasing demands. European Union targets on its energy roadmap states that by 2030, a reduction of 40% of CO2 emissions regarding the 1990 levels must be done and full transition must be completed by 2050. Thus, EU member countries, such Spain, are carrying out lots of investments to transform their power generation structure by promoting the installation of renewable energy power plants, with a significant visual and environmental impact. In the case of Spain, it is planned that, by 2030, 27% of final power consumption must be renewable, with approximately 31 GW of installed wind energy (8 GW must be installed in the next 10 years). Wind energy is supposed to be one of the generation leaders in this transformation context due to its high performance, high availability and fast decreasing costs. Nevertheless, wind farms have been installed on-shore with great success since the decade of the 90s covering the locations with the best wind resource. Thus, many of the installed wind turbines have overcome the half part of their expected lifespan and their payback periods, but the learning curve of the wind energy technology has improved exponentially since then. This paper is focused on the true valorization of an existing wind farm and the efficacy of the exploitation of the site’s wind resource. A novel repowering decision support model based on the opportunity cost analysis between repowering the current wind farm with the latter technologies and full depletion of the wind farm is proposed and applied to the Spanish Iberian Peninsula case study. Results show that the repowering option is significantly attractive in most cases and its proper application could have, not only a positive environmental effect, but also an economic impact on the sustainability of this source of energy.S

Câncer mamário: conhecimentos, atitudes e práticas para detecção prévia em Amalfi, Antioquia

ABSTRACT: To characterize informed and traditional knowledge on breast cancer, as well as attitudes, and practices for its early detection among 30 to 69 years old women in the urban area of the municipality of Amalfi, Antioquia. Methodology: Crosssectional study using a survey involving 335 women, selected via simple random sampling using housing addresses provided by the Secretariat for City Planning. Results: The combined score for breast cancer knowledge, risk factors, and symptoms was 14 (standard deviation: 3.6) out of 22 possible points, which shows an intermediate understanding of the topic. In 30 to 49 years old women, 82 % of them knew what breast cancer self-examination was, 14 % knew what clinical breast cancer exams were, and 68 % knew what a mammography was. On the contrary, in 50 to 69 years old women, percentages for the same criteria were 62 %, 10 %, and 63 %, respectively. 95 % of the respondents reported that early detection methods are important for cancer prevention or its timely treatment. 71.9 % of the 39 to 49 years old respondents, as well as 67.1 % of 50 to 69 years old women had already performed breast self-examination. 41.5 % of women had taken a clinical breast exam, without significant differences between age groups. Only 39.2 % of 50 to 69 years old women, had had a mammography. Conclusions: Knowledge on breast cancer, as well as attitudes, and practices for its early detection show deficiencies among the compared age groups; however, women present a favorable disposition towards breast cancer early detection, which may favor a strengthening of knowledge about this type of cancer and engage women in involving themselves in procedures for its detection.RESUMEN: Caracterizar los conocimientos sobre el cáncer de seno, y los saberes, las actitudes y las prácticas sobre su detección temprana en mujeres entre 30 y 69 años de edad del área urbana del municipio de Amalfi, Antioquia. Metodología: estudio de corte utilizando una encuesta con 335 mujeres, seleccionadas mediante muestreo aleatorio simple a partir de las direcciones de viviendas proporcionadas por la Secretaría de Planeación Municipal. Resultados: El puntaje combinado de conocimientos de cáncer de seno, factores de riesgo y síntomas fue 14 (desviación estándar: 3,6) de 22 puntos posibles, evidenciando un conocimiento intermedio en este tema. En mujeres entre 30 y 49 años, el 82, 14 y 68 % sabían qué era el autoexamen, el examen clínico y la mamografía respectivametne, comparado con el 62, 10 y 63 % en mujeres entre 50 y 69 años. El 95 % de las participantes reportó que los métodos de detección temprana son importantes para la prevención o el tratamiento oportuno del cáncer. El 71,9 % de las participantes entre 30 y 49 años de edad, y el 67,1 % entre 50 y 69 años se realizó el autoexamen de seno. El examen clínico de seno se lo hizo el 41,5 % de las mujeres, sin diferencias significativas entre los grupos de edad. Solamente el 39,2 % de las mujeres entre los 50 y 69 años de edad se habían realizado la mamografía. Conclusiones: Los conocimientos sobre el cáncer de seno, y las actitudes y las prácticas de su detección temprana presentan deficiencias en las edades comparadas; sin embargo, existe una disposición favorable por parte de las mujeres hacia la detección temprana, que puede favorecer el fortalecimiento de conocimientos sobre este tipo de cáncer y motivar la práctica de su detección

The ecological economy, inverse logistics and the necessary cost system

Considerando la innegable crisis medioambiental, se hace vital la consideración de la naturaleza y las como elementos de costos, y dado el cambio de conciencia de los consumidores actualmente, al requerir productos fabricados ecológicamente responsable, surge entonces la economía alternativa y la gestión de logística inversa en las empresas como propuesta y respuesta a esta creciente demanda de bienes y servicio que estén en armonía con la naturaleza. En efecto, se expresa la logística inversa, como herramienta para viabilizar la economía ecológica, la cual sin negar la rentabilidad, pretender visibilizar el impacto medioambiental producto de la actividad económica en la contabilidad de costos de las empresa, apoyándose en algunos sistema de costeo, tales como ABC, para comenzar a evidenciar o visibilizar los costos (cómo daños) asociados al medioambiente, y progresivamente haciendo a las empresas cada vez más responsable de los desechos, productos desechados o fuera de especificación que producen. Todo esto como resultado de una investigación descriptiva con un diseño documental y la revisión documental como técnica de manejo de la información, donde se logra interpretar y comprender la urgente necesidad, por presiones normativas, sociales y organizaciones de transformar la gestión tradicional, en una gestión más responsable.Considering the undeniable environmental crisis, the consideration of nature and the elements as costs becomes vital, and given the change in consciousness of consumers today, when requiring ecologically responsible manufactured products, then the alternative economy and reverse logistics management arises in companies as a proposal and response to this growing demand for goods and services that are in harmony with nature. In effect, reverse logistics is expressed as a tool to make the ecological economy viable, which without denying profitability, intends to make visible the environmental impact of economic activity in the cost accounting of companies, relying on some costing system, such as ABC, to begin to demonstrate or make visible the costs (such as damages) associated with the environment, and progressively making companies increasingly responsible for the waste, discarded or out-of-specification products they produce. All this as a result of a descriptive investigation with a documentary design and the documentary review as an information management technique, where it is possible to interpret and understand the urgent need, due to normative, social and organizational pressures to transform traditional management into management. more responsible

La capacidad prospectiva y de visualización del escáner láser 3D aplicado al plan de conservación preventiva del conjunto cerámico, piedra y hierro de Antoni Gaudí y Josep María Jujol en la catedral gótica de Mallorca

[ES] En este trabajo se presenta la eficiencia prospectiva y de visualización del escáner láser 3D como herramienta aplicada a la elaboración de un plan de conservación preventiva sobre la obra cerámica de Antoni Gaudí y Josep María Jujol en la catedral gótica de Mallorca. El uso de esta técnica ha posibilitado su investigación en relación al almacenamiento digital y metrológico de toda la superficie y elementos plásticos integrados. De esta manera se determina la creación de una base de datos multidisciplinar e interactiva con contenidos documentales, técnico-materiales y prescriptivos a fin de elaborar el correspondiente plan de conservación preventiva.[EN] In this work it is presented the prospective and visualization efficiency of the 3D laser scanner as a tool applied to the elaboration of a preventive conservation plan of the ceramic done by Antoni Gaudí and Josep Maria Jujol in the gothic cathedral of Mallorca .The usage of this technique has enabled its investigation regarding digital information storage and metrology of the whole surface and plastic elements in it. This ways it is determined the creation of a multidisciplinary and interactive database with documental, technical and prescriptive content in order to compose the preventive conservation plan.HAR2009-09929. Ministerio de Ciencia e Innovación., Diagnosis por imagen e interpretación histórico-artística en los procesos de recuperación de la decoración mural. Islas Baleares. AAEE 0091/09.Conselleria de Innovació, Interior y Justicia del Govern de les Illes Balears., Documentación del proceso de restauración de la obra de Gaudí y Jujol en el conjunto absidal intergrado por el mural cerámico, cátedra de piedra y hierros de la capilla Real en la Catedral de Mallorca. AAEE123/09. Conselleria de Innovació, Interior y Justicia del Govern de les Illes Balear., Utilización del láser en el proceso de restauración de la obra de Gaudí en la Catedral de Mallorca. AECID (D/027824/09, D/031964/10).Ruiz, JA.; Garcés, S.; Gambús, M.; Mas, C.; Perales, F.; Ponseti, X. (2012). La capacidad prospectiva y de visualización del escáner láser 3D aplicado al plan de conservación preventiva del conjunto cerámico, piedra y hierro de Antoni Gaudí y Josep María Jujol en la catedral gótica de Mallorca. Virtual Archaeology Review. 3(5):77-80. https://doi.org/10.4995/var.2012.4528OJS778035GONZÁLEZ MUÑOZ, Manuel J. et al (2010): "Uso de sistemas basados en escáner 3D para digitalización y estudio del patrimonio arqueológico" en Virtual Archaeology Review, pp. 99-102, [online] http://www.arqueologiavirtual.com/var/num1/23.pdf [Consulta: 10-02-2011]MARAMBÍO, A y GARCIA, P.(2006): "Escáner laser: modelo 3D y ortimagenes arquitectónicas de la iglesia de Santa Maria del Mar en Barcelona", ACE: architecture, city and evironment, nº2, pp. 178-187.RUBIO GIL, Daniel et al (2010): "Nuevos métodos para viejas tecnologías: Análisis y documentación de los materiales arqueológicos mediante la aplicaciación de sistemas láser-scanner 3D", en Virtual Archaeology Review, pp. 169-173, [online] http://www.arqueologiavirtual.com/var/num1/5.pdf [Consulta: 20-02-2011]TEJADO SEBASTIAN, Jose M. (2005): "Escaneado en 3D y prototipado de piezas arquelógicas: Las nuevas tecnologías en el registro , conservación y difusión del patrimonio arqueológico", en Iberia: Revista de la Antigüedad, nº 8, pp. 135-160

The Marboré Symphony: music for the deglaciation and Holocene in the central Pyrenees

20th Congress of the International Union for Quaternary Research (INQUA), Dublín, 2019Geological sequences have been used as the main basis for musical pieces both as inspiration for musicians and as raw materials (geochemical data, stratigraphic logs, cycles and frequencies) for compositions produced by computer programs. Telling our stories of Quaternary changes with music presents an opportunity to reach a wider audience and to integrate art and science. Here we present an example of how to compose music from Quaternary lake sequences and illustrate in a new way the main changes in the Pyrenean landscapes since deglaciation. The creation of this music was undertaken within the framework of the REPLIM project, an INTERREG- POCTEFA – project aimed to create a network of climate change observatories on lakes and wetlands in the Pyrenees. Based on the sediment sequence from Marboré Lake (42°41′44.27″N, 0° 2′24.07″E, 2612 m a.s.l), we have selected lithological, compositional and pollen data (Leunda et al, 2017; Oliva et al., 2018) to represent the main changes in the lake and the region during the last 15000 years. To transform the geological data into musical notes, we have used a similar approach than in previous experiences (Simon et al, 2015) but in this case, notes were assigned to compositional range intervals and the tempos were defined using sediment accumulation rates. Different melodies and instruments were assigned at each data set: TOC and Br/Ti as lake bioproductivity, selected pollen data for vegetation dynamics in the valleys, Si/Ti as sediment influx and Pb/Ti as anthropogenic impact. An electronic version of the Marbore Symphony was created by computer software based on the raw data. The music group O’Carolan (http://www.ocarolanfolk.com) transformed the electronic version into a six minutes long acoustic version. The Symphony premiered in the town of Bielsa on December 14th, 2018. The Marboré music project has served to increase citizenship awareness about climate change in the Pyrenees and provided a new tool to better communicate past and future changes in the landscapesInstituto Pirenaico de Ecología, EspañaUniversidad de Zaragoza, EspañaGrupo O´Carolan, EspañaInstituto Geológico y Minero de España, EspañaUniversidad Autonoma de Madrid, EspañaUniversidad del Pais Vasco, Españ

Impact of measurable residual disease by decentralized flow cytometry: a PETHEMA real-world study in 1076 patients with acute myeloid leukemia

The role of decentralized assessment of measurable residual disease (MRD) for risk stratification in acute myeloid leukemia (AML) remains largely unknown, and so it does which methodological aspects are critical to empower the evaluation of MRD with prognostic significance, particularly if using multiparameter flow cytometry (MFC). We analyzed 1076 AML patients in first remission after induction chemotherapy, in whom MRD was evaluated by MFC in local laboratories of 60 Hospitals participating in the PETHEMA registry. We also conducted a survey on technical aspects of MRD testing to determine the impact of methodological heterogeneity in the prognostic value of MFC. Our results confirmed the recommended cutoff of 0.1% to discriminate patients with significantly different cumulative-incidence of relapse (-CIR- HR:0.71, P < 0.001) and overall survival (HR: 0.73, P = 0.001), but uncovered the limited prognostic value of MFC based MRD in multivariate and recursive partitioning models including other clinical, genetic and treatment related factors. Virtually all aspects related with methodological, interpretation, and reporting of MFC based MRD testing impacted in its ability to discriminate patients with different CIR. Thus, this study demonstrated that “real-world” assessment of MRD using MFC is prognostic in patients at first remission, and urges greater standardization for improved risk-stratification toward clinical decisions in AML.This study was supported by the Centro de Investigación Biomédica en Red – Área de Oncología - del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369, CB16/12/00233, CB16/12/00284 and CB16/12/00400), Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS No. PI16/01661, PI16/00517 and PI18/01946), Gerencia Regional de Salud de CyL (GRS 1346/A/16) and the Plan de Investigación de la Universidad de Navarra (PIUNA 2014-18). This study was supported internationally by the Cancer Research UK, FCAECC and AIRC under the Accelerator Award Program EDITOR