Search results for " Maintenance."

Two operative risk indicators as tools for negotiating contracts between curators of Museums and HVAC technical services providers

2020

Abstract The purpose of Heating, Ventilating and Air-Conditioning (HVAC) systems in museums is to properly control important microclimate parameters; such systems, in fact, apart from ensuring the visitors’ wellbeing, are requested to guarantee suitable indoor conditions for the proper conservation of the important cultural goods hosted by museums. Hence, in case of disservice, or interruption due to maintenance interventions, it is important to quantify the economic damage induced to exhibited and/or stored works of art (or even to the building museum itself). Accordingly, it is essential to guarantee the shortest possible period of disservice during which probable damages for the works of…

L’art. 28 dello Statuto e le trasformazioni del lavoro: cinquant’anni portati bene, ma non troppo

2020

L’art. 28 dello Statuto dei lavoratori ha attraversato un cinquantennio di storia del conflitto sindacale italiano. Si tratta di un rimedio ancora attuale, che necessità di un intervento manutentivo alla luce delle trasformazioni del diritto del lavoro. Partendo dalla validità del modello normativo, il saggio individua le criticità per il legislatore in una prospettiva de jure condendo.

Bitumen stabilized ballast: a potential solution for railway track-bed

2016

Railway ballast degradation under dynamic loads progressively leads to loss of mechanical performance and geometry of the track, so that maintenance interventions are frequently needed. In order to system- atically avoid this issue, recently solutions have been proposed to reinforce track-bed by using polyur- ethane and/or resins as well as asphalt layers among others. Nonetheless, their main limitations are related to the high initial cost and low productivity. To cope with these limitations, in this study, bitumen stabilized ballast (BSB) is proposed as a new solu- tion for ballast stabilization. This method aims at improving durability and reducing settlement by mod- ifying both stiffnes…

Novel performance-based technique for predicting maintenance strategy of bitumen stabilised ballast

2018

Abstract Despite being the most used worldwide, railway ballasted tracks presents high maintenance cost related to ballast settlement and particle degradation. With the aim of reducing life cycle costs, bitumen stabilised ballast (BSB) has been recently proposed as a relatively cheap alternative maintenance solution to be applied to existing tracks. This study aims at assessing the potential advantages of this technology, defining a novel maintenance strategy of traditional ballasted track-beds. A protocol for the application of the BSB technology and its associated maintenance strategy is defined. To estimate minor and major maintenance operations of BSB scenario in comparison to tradition…

A Bayesian approach for predictive maintenance policy with imperfect monitoring

2009

In the traditional preventive maintenance policy, the periodic maintenance activities are scheduled on the basis of the a-priori information about the failure behaviour of the population which the component belongs to, by assuming a probability distribution function and by estimating the involved statistical parameters. On the contrary, with the predictive approach, the maintenance activity is scheduled on the basis of the real degradation level of the component. So, it is possible to reduce the failure probability and, at the same time, to use the component for almost all its useful life. For this reason, the predictive maintenance policy makes possible the reduction of the maintenance cos…

L’antica tradizione produttiva, il restauro e la manutenzione delle campane della Fonderia Virgadamo a Burgio, in Sicilia

2015

La percezione della città storica è sempre stata segnata dalla presenza dei campanili, uno dei segni architettonici più rilevanti nell’identificazione di un edificio sacro. Oltre a segnare il paesaggio, il campanile, attraverso il suono delle campane, scandisce lo scorrere del tempo, annuncia gli accadimenti e richiama le comunità di fedeli alla preghiera. La campane fanno parte del patrimonio culturale locale ed il loro suono è un bene che appartiene alla collettività. A Burgio, in Sicilia, l’antica tradizione produttiva delle campane di bronzo sopravvive da oltre cinque secoli, preservata e tramandata da generazione in generazione nella fonderia della famiglia Virgadamo. Le realizzazioni …

La resale price maintenance nel commercio librario. Limitare la concorrenza per promuovere la cultura?

2013

Traendo spunto dalle vicende della legge n. 128/2011, che limita lo sconto massimo praticabile al pubblico sul prezzo di copertina dei libri, pprovata con largo consenso e presto abrogata nell’indifferenza generale, l’articolo propone una approfondita analisi del modello nel quale tale legge si inscrive e delle soluzioni alternative che si riscontrano nel contesto europeo. L’indagine intende, quindi, riflettere sulla fondatezza degli assunti tradizionalmente posti alla base della difesa della Rpm libraria. Taking the cue from the events of the Law n. 128/2011, limiting the discounts on books cover price, which was passed by broad consensus and soon implicitly repealed amid the general indif…

2014

In vertebrate nervous systems myelination of neuronal axons has evolved to increase conduction velocity of electrical impulses with minimal space and energy requirements. Myelin is formed by specialised glial cells which ensheath axons with a lipid-rich insulating membrane. Myelination is a multi-step process initiated by axon-glia recognition triggering glial polarisation followed by targeted myelin membrane expansion and compaction. Thereby, a myelin sheath of complex subdomain structure is established. Continuous communication between neurons and glial cells is essential for myelin maintenance and axonal integrity. A diverse group of diseases, from multiple sclerosis to schizophrenia, ha…

Recovery of Bioactive Compounds from Marine Organisms: Focus on the Future Perspectives for Pharmacological, Biomedical and Regenerative Medicine App…

2023

Marine environments cover more than 70% of the Earth’s surface and are among the richest and most complex ecosystems. In terms of biodiversity, the ocean represents an important source, still not widely exploited, of bioactive products derived from species of bacteria, plants, and animals. However, global warming, in combination with multiple anthropogenic practices, represents a serious environmental problem that has led to an increase in gelatinous zooplankton, a phenomenon referred to as jellyfish bloom. In recent years, the idea of “sustainable development” has emerged as one of the essential elements of green-economy initiatives; therefore, the marine environment has been re-evaluated …

An integrated methodological approach for optimising complex systems subjected to predictive maintenance

2021

Abstract The present paper addresses the relevant topic of maintenance management, widely recognised as a fundamental issue involving complex engineering systems and leading companies towards the optimisation of their assets while pursuing cost efficiency. With this regard, our research aims to provide companies with a hybrid methodological approach based on Multi-Criteria Decision-Making (MCDM) capable to deal with the main failures potentially involving complex systems subjected to predictive maintenance. Such an approach is going to be integrated within the framework of traditional Failure Mode Effects and Criticality Analysis (FMECA), whose strengths and weaknesses are considered. In pa…