Search results for "OLDS"
showing 10 items of 602 documents
Investigation of heat transfer in spacer-filled channels by experiments and direct numerical simulations
2016
Abstract The analysis of flow fields and heat or mass transfer phenomena is of great importance in the optimum design of spacer-filled channel geometries for a variety of membrane-based processes. In the present work, models of spacer-filled channels often adopted in Membrane Distillation are simultaneously investigated by experiments and Computational Fluid Dynamics (CFD). Experiments rely on a non-intrusive technique, based on the use of Thermochromic Liquid Crystals (TLC) and digital image processing, and provide the local distribution of the convective heat transfer coefficient on a thermally active wall. CFD relies on steady-state (laminar flow) simulations in the lower end of the Reyn…
Polyactide Biodegradable Scaffolds for Tissue Engineering Applications: Phase Separation-Based Techniques
2011
One of the most reliable techniques for the preparation of biodegradable scaffolds suitable for tissue engineering applications (e.g. regeneration of wounded/damaged tissues) is based on liquid/liquid phase separation of ternary solvent/antisolvent/polymer solutions. In particular, two phase separation protocols are examined here: Thermally Induced Phase Separation (TIPS) and Diffusion Induces Phase Separation (DIPS). According to the former protocol, a thermodynamically stable polymeric ternary solution is brought below its metastability/instability point (spinodal/binodal curve) by quench in a cooling medium: under opportune conditions, a foam-like structure is formed by nucleation and 3-…
Flow and mass transfer in spacer-filled channels for reverse electrodialysis: a CFD parametrical study
2016
Abstract In reverse electrodialysis (RED) concentration polarization phenomena and pressure drop affect strongly the power output obtainable; therefore the channel geometry has a crucial impact on the system optimization. Both overlapped and woven spacers are commonly commercialised and adopted for RED experiments; the latter exhibit some potential advantages, such as better mixing and lower shadow effect, but they have been poorly investigated in the literature so far. In this work, computational fluid dynamics was used to predict fluid flow and mass transfer in spacer-filled channels for RED applications. A parametric analysis for different spacer geometries was carried out: woven (w) and…
CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of the minimum impeller speed for complete suspension
2012
Abstract In the literature on mechanically agitated solid–liquid systems, several methods are described to estimate the minimum impeller speed Njs at which all particles are suspended, but few studies have been devoted so far to their critical comparative assessment [67] . In the present paper, several alternative Njs prediction methods are applied to CFD results obtained for selected test cases covering a broad range of suspension conditions and impeller speeds. Results are compared with one another and with classic empirical correlations [88] . The aim of the work is to assess the adequacy of different methods for predicting Njs and, more generally, to contribute to a viable CFD-based str…
CFD simulations of early- to fully-turbulent conditions in unbaffled and baffled vessels stirred by a Rushton turbine
2021
Abstract Laboratory scale unbaffled tanks provided with a top cover and a baffled tank both stirred by a Rushton turbine were simulated by carrying out RANS simulations. Three different turbulence models were adopted (k- ω SST, k- e and the SSG Reynolds stress model) to predict the flow field and the relevant performance parameters (power and pumping numbers) of the tank operated from early to fully turbulent conditions. CFD results were compared with literature experimental data and DNS simulation results to validate and properly compare the models. In the range of Reynolds numbers investigated, results showed that, for the unbaffled tank, the SSG model based on Reynolds stresses is a bett…
RIFLESSI INTERNAZIONALI NELL’OREFICERIA DI SICILIA TRA XVIII E XIX SECOLO Un inedito esempio di collezionismo palermitano
2018
The volume is about a new private collection from Palermo that contains precious jewelery from the late eighteenth and nineteenth centuries.
Gioielli tra Sicilia e Malta nell'età del Barocco: tipologie e stili di area mediterranea
2016
Il saggio tratta di tipologie e stili diffusi nell'oreficeria siciliana e in quella dell'area mediterranea, in particolare a Malta e in Spagna, nel periodo barocco. The essay deals with typologies and styles widespread in the Sicilian jewelery and in the Mediterranean area, in particular in Malta and in Spain, in the Baroque period.
L'Orchestra di Auschwitz. Inchiesta su Alma Rosé
2023
Il libro è un'inchiesta sulla vita e il tempo di Alma Rosé (1906-1944), nipote di Gustav Mahler, debuttante e ragazza alla moda fra gli anni Venti e Trenta del secolo scorso, violinista il cui talento matura – paradossalmente – mentre l’ombra del nazismo si dispiega sull’Europa e infine direttrice dell’orchestra di Auschwitz. in un’epoca in cui la carriera del direttore d’orchestra era declinata soltanto al maschile. Giunta ad Auschwitz nell’estate 1943 e assegnata dapprima al Block degli esperimenti medici, Alma riuscì in breve tempo a diventare – nel piccolo mondo terribile del Lager – una specie di celebrità: ed è in quelle tenebre, d’altronde, che si svolge l’atto finale del dramma, oss…
On Geometric Simple Connectivity
2010
L'articolo intende dare una visione panoramica su ricerche recenti, molte delle quali sono da attribuire al V.Poenaru, sulla topologia di dimensione basse e sulla teoria geometrica dei gruppi.
A short survey on isoperimetric problem on non compact Riemannian manifolds
2009
In this text, we explain some known results about isoperimetric profile of complete smooth noncompact Riemannian manifolds of dimension 2, with one end, with two ends and with more than two ends.