Search results for "Process"
showing 10 items of 22310 documents
Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer
2019
In electro-membrane processes, a pressure difference may arise between solutions flowing in alternate channels. This transmembrane pressure (TMP) causes a deformation of the membranes and of the fluid compartments. This, in turn, affects pressure losses and mass transfer rates with respect to undeformed conditions and may result in uneven flow rate and mass flux distributions. These phenomena were analyzed here for round pillar-type profiled membranes by integrated mechanical and fluid dynamics simulations. The analysis involved three steps: (1) A conservatively large value of TMP was imposed, and mechanical simulations were performed to identify the geometry with the minimum pillar density…
A hierarchical model for novel schemes of electrodialysis desalination
2019
Abstract A new hierarchical model for the electrodialysis (ED) process is presented. The model has been implemented into gPROMs Modelbuilder (PSE), allowing the development of a distributed-parameters simulation tool that combines the effectiveness of a semi-empirical modelling approach to the flexibility of a layered arrangement of modelling scales. Thanks to its structure, the tool makes possible the simulation of many different and complex layouts, requiring only membrane properties as input parameters (e.g. membrane resistance or salt and water permeability). The model has been validated against original experimental data obtained from a lab scale ED test rig. Simulation results concern…
Optimisation analysis of Reverse Electrodialysis systems for power production from concentrated brines
2016
Reverse Electrodialysis (RED) is rapidly growing as technology to produce electric energy by mixing saline solutions with different salinity. Recent developments have shown promising results on real site installations, demonstrating the feasibility of the RED process on the pilot scale. Therefore, further modelling efforts are now needed to optimise the technology, in order to enhance the performance. In this work, an optimisation study for the RED process is presented, taking into account saline waters and concentrated brine as feed streams. The model, which is developed within GAMS environment, predicts the optimal set of process variables that maximise the process yield, as well as the g…
Ionic liquid binary mixtures: Promising reaction media for carbohydrate conversion into 5-hydroxymethylfurfural
2014
Abstract The conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF) has been studied in binary mixtures of ionic liquids (ILs), using strongly acidic resin Amberlyst 15 as the catalyst. In particular, both mono- and disaccharides, such as fructose, glucose and sucrose have been investigated. Considering the favorable effect exerted by chloride-based ionic liquids in the dissolution of carbohydrates, we used binary mixtures of 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) with [bmim + ] based ionic liquids differing in size, shape and coordination ability of the anion ([bmim][BF 4 ], [bmim][N(CF 3 SO 2 ) 2 ], [bmim][N(CN) 2 ], [bmim][SbF 6 ] and [bmim][CF 3 SO 3 ]). Carbohydrat…
Shaping 1,2,4-Triazolium Fluorinated Ionic Liquid Crystals
2023
The synthesis and thermotropic behaviour of some di-alkyloxy-phenyl-1,2,4-triazolium trifluoromethane-sulfonate salts bearing a seven-carbon atom perfluoroalkyl chain on the cation is herein described. The fluorinated salts presenting a 1,2,4-triazole as a core and differing in the length of two alkyloxy chains on the phenyl ring demonstrated a typical liquid crystalline behaviour. The mesomorphic properties of this set of salts were studied by differential scanning calorimetry and polarized optical microscopy. The thermotropic properties are discussed on the grounds of the tuneable structures of the salts. The results showed the existence of a monotropic, columnar, liquid crystalline phase…
Approches quantitatives de la production de fer sur le site hallstattien de Bragny-sur-Saône (Saône-et-Loire)
2007
This study is based on an inventory of iron knives dated from the 8th to the 5th centuries BC and discovered in funerary and settlement sites in the South-West of France. The corpus consists of 608 artefacts. We established a typology allowing us to present a chronological and spatial distribution of each type. We then tried to determine the functions of the knives according to their type and their length. For those discovered in graves other objects in the grave assemblage were used as an additional criterion. When the funerary context was very clearly defined, we tried to determine the function, in the grave itself, of the knives.
Design and Realization of a Bidirectional Full Bridge Converter with Improved Modulation Strategies
2020
In this paper a Full-Bridge Converter (FBC) for bidirectional power transfer is presented. The proposed FBC is an isolated DC-DC bidirectional converter, connected to a double voltage source&mdash
La cessazione dell'istanza (artt. 143-154)
2008
Capacità e incapacità
2018
Il volume prende in esame le più rilevanti questioni interpretative, che registrano tuttora discordanze di opinioni, relative alla capacità giuridica, di agire, nonché di intendere e di volere. Particolare attenzione è dedicata all’incidenza delle più o meno recenti novelle a protezione degli incapaci di agire sull’obiettivo, perseguìto dal legislatore, della valorizzazione della personalità, della dignità e dell’autodeterminazione di ciascun individuo, nella prospettiva di un ripensamento delle distinzioni, operate dalla dottrina prevalente, tra capacità giuridica e capacità di agire, e, con riguardo al minore, tra sfera personale e sfera patrimoniale. The volume shall consider the most re…
Il ruolo dei media informativi nelle emergenze: dal cortocircuito al sostegno
2012
Il saggio analizza il processo di gestione delle informazioni nei casi eccezionali, come i disastri naturali, che stravolgono le routines produttive dei media.