1,721,036 research outputs found
Detailed reconstruction and safety analysis of a pre–Seveso accident
Full text linkIndustrial safety has been a topic of growing interest during the last decades, mainly because of the increased awareness and knowledge about safety issues. In this framework, the detailed reconstruction of the dynamics of an explosion (1 killed and 8 injured) occurred, on the 26th of June 1971, at Noury Italy (a plant dedicated to the production of chemicals for hardening plastics) is worth of interest and it could be used to improve actual safety guidelines related to the storage of peroxides. The accident happened before whatever Seveso Directive release. Therefore, root-causes reconstruction and related risk assessment were carried out making a comparison between a hypothetical plant layout at that time and a modern plant layout implemented with minimum safety systems, such as acoustic alarms and adequate bypass lines. The accident reconstruction was carried out by doing a deep literature research, mainly based on newspaper clippings of the time, to both remodel the accident at best and draw the most likely layout of the plant. The latter is of fundamental importance to carry out a risk assessment procedure by applying the Recursive Operability Analysis (ROA), which allows for a direct generation of the fault trees that can provide an easy estimation of the probability of occurrence of all unwanted events. This method was applied to the Noury Italy case study to show the criticalities of the storage equipment also underlining the possible improvements which could be implemented also in the ‘70s, therefore preventing the fatal explosion
Recursive operability analysis as a tool for ATEX classification in plants managing explosive dusts
Full text linkSafety and prevention in workplaces are important issues, especially regards to risks with serious consequences for health and infrastructures, such as dust explosions, which have caused several industrial accidents during the last centuries and, actually, represent a critical issue in the industrial framework. The current European legislation, referred to as ATEX directive, identifies ATEX zones as parts of the plant where explosive atmospheres can be generated. In this work, a modified version of the classic Recursive Operability Analysis method, specifically tailored to define with an automatic procedure the ATEX zones related to flammable dust clouds, is proposed. The method is fast and effective, allowing for an automatic generation of fault trees from which the probability of occurrence defining the specific ATEX zone type can be estimated. This technique was successfully implemented in a chemical plant dedicated to the mixing of inert powders with a stearate powder, a hazardous dust classified as strongly explosible. The extent of all the ATEX zones identified within the plant was simulated with the ALOHA software, treating the dispersed dust cloud of stearate as a dense gas cloud. From the results, it was possible to identify not only type and extension of all the ATEX zones but also either the most critical parts of the plant or the most dangerous activities (e.g. human errors in the use of the forklift was found to account for about 97.7% to explosion probability in this type of plant)
LA RADIOLOGIA INTERVENTISTICA NEI TRAUMI
No full textII ruolo della radiologia interventistica nell'urgenza traumatica si è progressivamente ampliato alla luce della recente tendenza alla terapia conservativa, non chirurgica, anche nei traumi chiusi del torace e dell'addome di gradi severi, che sono indicati per il trattamento interventistico endovascolare e percutaneo. Nel paziente traumatizzato la TC spirale e l'angiografia sono le metodiche che, combinate, forniscono informazioni diagnostiche cruciali, insieme alla valutazione clinica, per la strategia terapeutica rappresentata dall'intervento chirurgico immediato, o da un'immediata terapia radiologica interventistica definitiva o da un intervento radiologico temporizzato seguito da chirurgia in elezione. Tre possibilità terapeutiche sono appannaggio della radiologia interventistica nei traumi, a seconda delle indicazioni: l'occlusione mediante catetere a palloncino di emorragie acute, l'embolizzazione per il controllo delle emorragie parenchìmali o degli arti nei pazienti emodinamicamente stabilizzati e il posizionamento di stent-graft (o stent ricoperti) per i traumi mono-vascolari
RADIOLOGIA INTERVENTISTICA. INTRODUZIONE CLINICA.
No full textNegli ultimi due decenni il ruolo della radiologia interventistica nell'urgenza si è progressivamente ampliato e oggi sostituisce a tutti gli effetti l'intervento chirurgico nel trattamento endovascolare di molte patologie ischemiche ed emorragiche e nel trattamento percutaneo delle raccolte fluide o ascessuali, delle ostruzioni biliari e urinarie.
In questi scenari, nel paziente acuto, dopo l'ecografia completata da Doppler, la TC spirale e l'angiografia sono le metodiche che, combinate, forniscono le informazioni diagnostiche ottimali: la TC è metodica di prima istanza per valutare lo stato degli organi parenchimatosi e per identificare la presenza di ematomi, urinomi e bilomi, mentre l'angiografia è metodica gola standard per la precisa localizzazione e l'identificazione dei vasi ischemici o responsabili dell'emorragia, per la diagnosi del tipo di danno vascolare (deiscenza vascolare, tromboembolia, dissezione, rottura completa o parziale, pseudoaneurisma, trombosi post-traumatica). Tali rilievi, insieme alla valutazione clinica, sono di fondamentale importanza per definire il tipo e il tempo ottimale di strategia terapeutica, scegliendo tra l'intervento chirurgico immediato, un'immediata e definitiva terapia radiologica interventistica o un intervento di radiologia interventistica che permetta di "temporizzare" la chirurgia in elezione
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Increasing Safety by Shifting Semi-Batch Polymerizations into Semi-Continuous Production
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