Search results for "Processes"
showing 10 items of 3831 documents
Palermo si cura. Pratiche culturali di mutuo soccorso come risposta alle fragilità della città (post)pandemica
2023
In un quadro di riferimento in cui la crisi è globalizzata ma diseguale e in mancanza di un sistema di welfare capace di rispondere alle urgenze dei contesti e dei gruppi sociali più marginalizzati, una risposta ai nuovi bisogni sociali ed individuali è stata offerta da reti solidali e da pratiche di mobilitazione dal basso che svolgono un ruolo di agency territoriale, spesso indipendentemente o in assenza di Istituzioni. Nel contesto palermitano un impegno agito da una pluralità di soggetti culturali già attivi sul territorio, riuniti in un’assemblea pubblica (Palermo si cura), durante il periodo del primo lockdown hanno dato vita ad azioni di mutuo soccorso per rispondere all’emergenza ec…
A Ferrite Tubular Linear Motor (FTLM): Analysis and design
2015
The electromagnetic linear machines have wide applications in the electromagnetic aircraft launch systems [1] and in transportation systems [2]. Additional energy saving and efficiency can be achieved using a linear motor in the refrigeration application [3]. Linear electromagnetic machines are also very suitable for high-speed packaging, manufacturing sectors and precision positioning. There are different linear motor topologies. Tubular permanent-magnets are particularly attractive since they have a high thrust force density and high efficiency, no end windings, and zero net attractive force between stator and armature. There are various tubular motor topologies, in which the armature may…
An overview of sustainability issues in manufacturing and building sector: a life cycle assessment approach
2014
In the latest decades, the industrial consumption of materials and energy has undergone a growth which may exceed the limits of earth resources. Therefore, a strong awareness of the need to use materials and energy in a more efficient way has arisen. A wide research interest on sustainability is present in the modern technical literature: Life Cycle Assessment (LCA) methodology and Design for Environment (DFE) procedures are nowadays widely investigated in many research labs all over the world. In this context, this paper focuses on LCA approaches in two main fields: manufacturing and building sector. As the former is regarded, sustainability issues are crucial topics and the reduction of e…
DETERMINAZIONE DELLA DURATA A FATICA DI COMPONENTI SOGGETTI A SOLLECITAZIONI SCHEMATIZZABILI COME PROCESSI ALEATORI A BANDA STRETTA
2016
In questo lavoro sono state sviluppate le espressioni analitiche per la determinazione della durata a fatica di componenti soggetti a svariate tipologie di sollecitazione aleatorie a banda stretta (con parametro di irregolarità 0.9<aX≤1), in particolare: processi non stazionari di tipo separabile, tensione normale monoassiale con tensione media costante, sollecitazione biassiale con tensioni normali agenti in fase, sollecitazione di sforzo normale e tensione tangenziale agenti in fase, propagazione della frattura. In this paper the analytical equations for the determination of the fatigue life of components subjected to various types of narrowband random processes of stress (having irregula…
Heterogeneous photocatalysis: a promising advanced oxidation process
2018
This chapter reports the fundamentals of heterogeneous PC. In particular, different kinetic models and the influence of some parameters (such as pH, temperature, light intensity) on the rate of PC are described, and the effects of some photocatalyst modifications are discussed. Methods for photoreactor modeling are analyzed and the coupling of PC with other AOPs using H2O2, O3, and peroxydisulfate are discussed.
Techno-economic analysis of integrated processes for the treatment and valorisation of neutral coal mine effluents
2020
Abstract The disposal of highly-concentrated neutral coal mine effluents into the environment constitutes a severe threat to the natural ecosystem. This work proposes and compares five novel treatment chains to purify the effluent and recover raw materials. The chains present different combinations of pre-treatment and concentration technologies. In all cases, the solution sent to the concentration step is concentrated up to saturation to recover water and sodium chloride. Concerning the technical performances, the treatment chains are compared in terms of total energy demand and salt recovery. Furthermore, the economic feasibility assessment is performed via a novel global parameter, i.e. …
Towards the implementation of circular economy in the water softening industry: A technical, economic and environmental analysis
2020
Abstract To reduce the environmental impact of the industrial sectors, circular strategies should be implemented to purify the effluents and recover raw materials. In this context, a novel integrated methodological approach is proposed to identify the most suitable strategy to improve the sustainability of the water softening industry via the treatment and recycling of the produced wastewater. Different concentration technologies and energy supply systems are compared to find economically feasible and environmentally friendly treatment systems. The investigated chains present the same pre-treatment step (nanofiltration and crystallization) and different concentration technologies: Multi-Eff…
Seawater Desalination. Conventional and Renewable Energy Processes
2009
A growing proportion of the world’s population is dependent on Seawater Desalination as a source of fresh water for both potable and civil use. One of the main drawbacks of conventional desalination technologies is the substantial energy requirement, which is facing cost increases in the global energy market. “Seawater Desalination” presents an overview of conventional and non-conventional technologies, with a particular focus on the coupling of renewable energies with desalination processes. The first section of this book presents, in a technical but reader-friendly way, an overview of currently-used desalination processes, from thermal to membrane processes, highlighting the relevant tech…
CFD prediction of flow, heat and mass transfer in woven spacer-filled channels for membrane processes
2021
Abstract Flow and heat or mass transfer in channels provided with woven spacers made up of mutually orthogonal filaments were studied by Computational Fluid Dynamics. The problem addressed was the combined effect of the parameters that characterize the process: pitch to height ratio P/H (2, 3 and 4), flow attack angle θ (0, 7, 15, 20, 30, 40 and 45°) and Reynolds number Re (from ~1 to ~4000). The Prandtl number was 4.33, representative of water at ~40°C, while the Schmidt number was 600, representative of NaCl solutions. Simulations were performed by the finite volume code Ansys CFX™ 18.1 using very fine grids of ~6 to ~14 million volumes. For Re > ~400, the SST turbulence model was used to…
Pressure drop at low reynolds numbers in woven-spacer-filled channels for membrane processes: CFD prediction and experimental validation
2017
The energy consumption due to pumping power is a crucial issue in membrane processes. Spacers provide mechanical stability and promote mixing, yet increasing pressure drop. Woven spacers and their behaviour at low Reynolds numbers are less studied in the literature. Nevertheless, they are typical of some membrane technologies, as reverse electrodialysis (RED). RED is a promising technology for electric power generation by the chemical potential difference of two salt solutions within a stack equipped by selective ion-exchange membranes. The mechanical energy required for pumping the feed solutions, can dramatically reduce the net power output. In this work computational fluid dynamics (CFD)…