Search results for "MAINTENANCE"
showing 10 items of 392 documents
Neuronal cell cycle: the neuron itself and its circumstances.
2015
Neurons are usually regarded as postmitotic cells that undergo apoptosis in response to cell cycle reactivation. Nevertheless, recent evidence indicates the existence of a defined developmental program that induces DNA replication in specific populations of neurons, which remain in a tetraploid state for the rest of their adult life. Similarly, de novo neuronal tetraploidization has also been described in the adult brain as an early hallmark of neurodegeneration. The aim of this review is to integrate these recent developments in the context of cell cycle regulation and apoptotic cell death in neurons. We conclude that a variety of mechanisms exists in neuronal cells for G1/S and G2/M check…
A partire dalla manutenzione: strategie per i siti archeologici
2010
A dieci anni dal Regolamento attuativo della Legge Merloni, il contributo punta ad aggiornare lo stato dell’arte sulla manutenzione dei siti archeologici. Nonostante i numerosi passi avanti, il quadro mostra ancora alcune ambiguità, mentre molti siti continuano a versare in condizioni precarie. La limitatezza delle risorse disponibili, tanto più grave pensando alla vastità del patrimonio culturale, per molto tempo ha costituito un alibi per trascurare la manutenzione. Invece essa costituisce un incentivo per una più efficiente gestione. Si tratta: dell’ambiguità del rapporto manutenzione/conservazione, dei paradossi normativi e dei limiti della programmazione, della specificità della manute…
Ensuring the Conservative Process: The Roman Walls of Lugo Maintenance Plan
2016
In 2000 the walls of Lugo were added to the World Heritage List. In the Spanish scenario of UNESCO Sites this is the only one provided with a maintenance plan, which properly defines times for inspections and interventions, tools for the collection and management of data, human and financial resources. This plan has begun to ensure a conservation process which guarantees that this ancient artefact is used efficiently and safely over time. The walls are fully accessible and because of the dominant ramparts are used by citizens as a beloved and frequently used city park. This article aims to describe the strategy and the conservation process put in place on the Roman walls to preserve and kee…
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…