1,721,533 research outputs found
Application of standard EN 14491:2006 to cylindrical steel silos for dust explosion protection
Get PDF[ES] Las explosiones de polvo representan un serio peligro en aquellas industrias y silos en los que se manejan materiales combustibles. Para mitigar los efectos de una posible explosión generalmente se utilizan dispositivos de venteo, que pueden dimensionarse siguiendo la norma europea EN 14491:2006. Sin embargo, frecuentemente surgen complicaciones que hacen que la instalación de venteos sea
técnicamente complicada y muy costosa. El objetivo de este trabajo fue analizar la aplicación de la norma EN 14491:2006 a los silos metálicos cilíndricos, remarcando las dificultades y limitaciones existentes
y explicando sus aspectos clave para poder aplicarla correctamente. También se ha calculado el coste que puede suponer la protección de silos mediante venteos. Finalmente, se proporcionan algunas sugerencias para afrontar la protección de silos, información sobre métodos alternativos de cálculo de venteos y tendencias de futuro en este campo.[EN] Dust explosions represent a serious hazard in industries and silo facilities that handle combustible materials. Venting devices are commonly used to try to mitigate the damage caused by any dust
explosion. To calculate vent area size, the recommendations given in European standard EN 14491:2006 can be used. However, the protection of silos is not always simple, and frequently the installation of vents becomes technically difficult and costly. The aim of the present work was to analyse the application of
standard EN 14491:2006 to cylindrical steel silos, remarking the existing difficulties and limitations and explaining some critical points in order to understand the aforementioned standard. In addition, the cost of protection by venting in silos was studied. Finally, the authors have provided some suggestions to solve the protection of silos, alternative methods to calculate vent areas and expected future trends in this field.SILos autores agradecen a la Consejería de Edu- cación de la Comunidad de Castilla y Léon y al Fondo Social Europeo su apoyo econó- mico a estos trabajos, mediante un proyecto (LE010B05) y una beca de investigación
Aplicación de la norma EN 14491:2006 a los silos de acero cilíndricos para la protección frente a explosiones de polvo
Get PDFDust explosions represent a serious hazard in industries and silo facilities that handle combustible materials. Venting devices are commonly used to try to mitigate the damage caused by any dust explosion. To calculate vent area size, the recommendations given in European standard EN 14491:2006 can be used. However, the protection of silos is not always simple, and frequently the installation of vents becomes technically difficult and costly. The aim of the present work was to analyse the application of standard EN 14491:2006 to cylindrical steel silos, remarking the existing difficulties and limitations and explaining some critical points in order to understand the aforementioned standard. In addition, the cost of protection by venting in silos was studied. Finally, the authors have provided some suggestions to solve the protection of silos, alternative methods to calculate vent areas and expected future trends in this field.Las explosiones de polvo representan un serio peligro en aquellas industrias y silos en los que se manejan materiales combustibles. Para mitigar los efectos de una posible explosión generalmente se utilizan dispositivos de venteo, que pueden dimensionarse siguiendo la norma europea EN 14491:2006. Sin embargo, frecuentemente surgen complicaciones que hacen que la instalación de venteos sea técnicamente complicada y muy costosa. El objetivo de este trabajo fue analizar la aplicación de la norma EN 14491:2006 a los silos metálicos cilíndricos, remarcando las dificultades y limitaciones existentes y explicando sus aspectos clave para poder aplicarla correctamente. También se ha calculado el coste que puede suponer la protección de silos mediante venteos. Finalmente, se proporcionan algunas sugerencias para afrontar la protección de silos, información sobre métodos alternativos de cálculo de venteos y tendencias de futuro en este campo
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
EXPLOSÃO EM SILOS VERTICAIS SEGUNDO AS NORMAS: NFPA 68:2023, EN 14491:2012 E NBR 16385:2015
No full textThe growth of Brazilian agricultural production, as shown by data from CONAB (2025) and IBGE (2025), has increased the use of vertical silos for grain storage and, consequently, the occurrence of explosions caused by combustible dust, especially in corn and soybean facilities. This study analyzes the sizing of the vent area for explosion pressure relief and mitigation in vertical silos, in accordance with standards NFPA 68:2023, EN 14491:2012 and NBR 16385:2015, and presents the development of the V-Calc software, created in C# for calculating the relief area according to each methodology. Silos with different H/D ratios and variations of P_(red ) were evaluated. The results showed that NFPA 68:2023 maintains constant areas for H/D ≤ 2.0, whereas EN 14491:2012 yields higher values in all cases due to the minimum limit of P_stat≥0,1 bar, evidencing a more conservative approach. The V-Calc software proved effective for the analysis and design of pressure relief systems, contributing to safer, more resilient, and sustainable projects, in line with the Sustainable Development Goals.O crescimento da produção agrícola brasileira, evidenciado por dados da CONAB (2025) e do IBGE (2025) tem intensificado o uso de silos verticais para armazenagem de grãos e, consequentemente, a ocorrência de explosões por poeiras combustíveis, sobretudo em unidades com milho e soja. Este trabalho analisa o dimensionamento da área de ventilação para alívio e atenuação da pressão de explosão em silos verticais, conforme as normas NFPA 68:2023, EN 14491:2012 e NBR 16385:2015, e apresenta o desenvolvimento do software V-Calc, implementado em linguagem C# para cálculo de área de alívio de pressão segundo cada metodologia. Foram avaliados silos de diferentes relações H/D e variação de P_(red ). Os resultados indicam que a NFPA 68:2023 mantém áreas constantes para H/D ≤ 2,0, enquanto a EN 14491:2012 fornece valores superiores em todos os casos, em função do limite mínimo de P_stat≥0,1 bar, caracterizando um comportamento mais conservador. O V-Calc mostrou-se eficaz na análise e dimensionamento de sistemas de alívio de pressão, contribuindo para projetos mais seguros e resilientes, em consonância com os objetivos de desenvolvimento sustentável
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Socio-Technical Security Metrics (Dagstuhl Seminar 14491)
Get PDFThis report documents the program and the outcomes of Dagstuhl Seminar 14491 "Socio-Technical Security Metrics". In the domain of safety, metrics inform many decisions, from the height of new dikes to the design of nuclear plants. We can state, for example, that the dikes should be high enough to guarantee that a particular area will flood at most once every 1000 years. Even when considering the limitations of such numbers, they are useful in guiding policy. Metrics for the security of information systems have not reached the same maturity level. This is partly due to the nature of security risk, in which an adaptive attacker rather than nature causes the threat events. Moreover, whereas the human factor may complicate safety and security procedures alike, in security this "weakest link" may be actively exploited by an attacker, such as in phishing or social engineering. In order to measure security at the level of socio-technical systems, one therefore needs to compare online hacking against such social manipulations, since the attacker may simply take the easiest path. In this seminar, we searched for suitable metrics that allow us to estimate information security risk in a socio-technical context, as well as the costs and effectiveness of countermeasures. Working groups addressed different topics, including security as a science, testing and evaluation, social dynamics, models and economics. The working groups focused on three main questions: what are we interested in, how to measure it, and what to do with the metrics
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