Search results for "mecA"
showing 10 items of 475 documents
A combined multi-criteria approach to support FMECA analyses: A real-world case
2018
[EN] The paper proposes an approach that combines reliability analyses and multi-criteria decision methods to optimize maintenance activities of complex systems. A failure mode, effects, and criticality analysts (FMECA) is initially performed and the fuzzy TOPSIS (FTOPSIS) method is then applied to rank previously identified failure modes. For prioritization, failure modes are assessed against three evaluation criteria that differ from those traditionally involved in risk priority number (RPN) computation (i.e. severity, occurrence and detection). Two criteria refer to the maintenance management reflecting the operational time taken by the maintenance activity performed after the occurrence…
Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment
2013
NEXT-100 experiment aims at searching the neutrinoless double-beta decay of the Xe-136 isotope using a TPC filled with a 100 kg of high-pressure gaseous xenon, with 90% isotopic enrichment. The experiment will take place at the Laboratorio Subterraneo de Canfranc (LSC), Spain. NEXT-100 uses electroluminescence (EL) technology for energy measurement with a resolution better than 1% FWHM. The gaseous xenon in the TPC additionally allows the tracks of the two beta particles to be recorded, which are expected to have a length of up to 30 cm at 10 bar pressure. The ability to record the topological signature of the beta beta 0 nu events provides a powerful background rejection factor for the bet…
Description and commissioning of NEXT-MM prototype: first results from operation in a Xenon-Trimethylamine gas mixture
2014
[EN] A technical description of NEXT-MM and its commissioning and first performance is reported. Having an active volume of ∼35 cm drift × 28 cm diameter, it constitutes the largest Micromegas-read TPC operated in Xenon ever constructed, made by a sectorial arrangement of the 4 largest single wafers manufactured with the Microbulk technique to date. It is equipped with a suitably pixelized readout and with a sufficiently large sensitive volume (∼23 l) so as to contain long (∼20 cm) electron tracks. First results obtained at 1 bar for Xenon and Trymethylamine (Xe-(2%)TMA) mixture are presented. The TPC can accurately reconstruct extended background tracks. An encouraging fu…
Structure and composition heterogeneity of a FeAl alloy prepared by one-step synthesis and consolidation processing and their influence on grain size…
2006
Abstract This paper aims to characterize a bulk dense FeAl (47 at.%) alloy synthesized and consolidated by one-step current-activated pressure-assisted processing of nanocrystalline elemental powders. The end-product was analyzed using a combination of scanning (SEM) and transmission electron microscopies (TEM), electron back-scattering diffraction (EBSD) as well as electron probe microanalysis (EPMA). Special attention was paid to verify the grain size (32–89 nm) previously determined by X-ray diffraction peak profile analysis. It has been found that this material displays equiaxed grains (0.8–4 μm in size) and contains limited structural defects like subgrains and dislocations. The EPMA r…
MECANISMOS DE COORDINACIÓN ESTRUCTURAL, NO ESTRUCTURAL E INFORMAL. PROPUESTA Y VALIDACIÓN DE ESCALAS DE MEDIDA / STRUCTURAL, NON- STRUCTURAL AND INFO…
2008
El presente trabajo tiene como objetivo diseñar y validar escalas para medir diversos mecanismos de coordinación estructural, no estructural e informal. Los primeros están vinculados a puestos u órganos específicos, y nos referimos al diseño de redes, equipos de proyecto y desarrollo, y equipos de trabajo. Los mecanismos de coordinación no estructural sirven de complemento a los anteriores. En este grupo se encuentran la normalización de procesos de trabajo, de habilidades y de resultados. Por último, los mecanismos de carácter informal son el esfuerzo de socialización y la adaptación mutua. Tras la generación de una batería de 43 ítems, se han comprobado sus propiedades psicométricas: fiab…
Thermal analysis and new insights to support decision making in retrofit and relaxation of heat exchanger networks
2011
International audience; Pinch analysis offers a rational framework for identifying energy saving targets and designing efficient heat recovery networks, especially in process industry. Several scientists have contributed to improve and automate the original pinch method over the last decades, increasing its capability to deal with a number of specific issues; the expertise of the analyst, however, remains determinant in achieving optimal results. In this paper a procedure for retrofit of existing networks is proposed, based on an integrate use of several techniques (either existing or innovative). The diagnosis of the existing network and of a "Minimum Energy Requirement" configuration emer…
Analysis of evaporative flux data for various climates
1992
International audience
ANALISI DI RISCHIO DELL’IMPIANTO SPERIMENTALE “SELECTIVE PRODUCTION OF EXOTIC SPECIES” (SPES) DELL’INFN DI LEGNARO
Il progetto di ricerca denominato EURISOL (European Isotope Separation On-Line Radioactive Ion Beam Facility), che vede coinvolti i principali laboratori di ricerca nucleari europei, è rivolto allo studio di progettazione e fattibilità di un impianto per la produzione di fasci di nuclei radioattivi posizionati nella cosiddetta “terra incognita” della carta dei nuclidi. Lo scopo principale è l’esplorazione della materia esotica (nuclei caratterizzati da un eccesso difetto di neutroni), con le sue possibili implicazioni nell’ambito della ricerca di base della fisica nucleare, nelle applicazioni in campo medico e dell’astrofisica, e ancora nello studio dei materiali utilizzati nei reattori nuc…
Progettazione e sviluppo del software R.A.D. per analisi FMECA
2012
Ad oggi l’analisi FMECA (Failure Modes, Effects and Criticality Analysis) si è dimostrata uno strumento di indagine molto utile per lo studio dell’affidabilità dei componenti dei vari sistemi di un impianto. Tuttavia, l’applicazione sistematica di tale metodologia, anche nel caso di impianti relativamente semplici, risulta onerosa in termini di risorse necessarie ai fini della sua conduzione e gestione. A supporto dell’analisi, esiste una buona varietà di software sviluppati per lo scopo, tuttavia spesso essi presentano alcune funzionalità selettive essendo dedicati all’impiego in ambiti specifici. Alla luce di tale limitazione si è pensato di realizzare e mettere a punto un software sempli…
Improved FMECA for effective risk management decision making by failure modes classification under uncertainty
2022
Failure Mode, Effects, and Criticality Analysis (FMECA) is a proactive reliability and risk management technique extensively used in practice to ensure high system performance by prioritising failure modes. Owing to the limitations of traditional FMECA, multi-criteria decision-making methods have been employed over the past two decades to enhance its effectiveness. To consider the vagueness and uncertainty of the FMECA evaluation process, an interval-based extension of the Elimination et Choice Translating Reality (ELECTRE) TRI method is proposed in the present paper for the classification of failure modes into risk categories. Therefore, ratings of failure modes against risk parameters are…