343 research outputs found
Il futuro delle ex-caserme? Non case ma servizi alla città
No full textL'articolo, a firma di Federica Cravero, recensisce la seconda giornata degli incontri "Torino. Argomenti per un futuro possibile" organizzati dal DAD sul tema delle "Caserme dismesse e non: aree di potenziale sperimentazione e sviluppo del territorio". Nell'articolo sono riportate, in forma di intervista, alcune frasi di Paolo Mellano, estratte dalla relazione introduttiva all'incontro
Improving fire performances of PEAL: More second-life options for recycled Tetra Pak®
No full textThe purpose of this work was to evaluate and improve the flammability and combustion behavior of the polyethylene-based material obtained from the recycling of Tetra Pak® (PEAL) to widen its use to applications where these properties are required. Firstly, its thermal stability was investigated with thermogravimetric analysis, resulting in an enhancement in the main degradation step temperature (from 385◦C to 421◦C) due to the presence of the aluminum-flakes. Then, to improve the poor flammability (HB in UL-94 test) and combustion behavior (Fire Performance Index of 0.07) of the raw material, two flame retardant approaches were tested: an intumescent system made of ammonium polyphosphate and pentaerythritol, and magnesium hydroxide. In addition, the effectiveness of polyethylene as a charring agent was evaluated. Characterization was made with UL-94, cone calorimeter, and morphologic analysis. For all the materials tested, the temperature of the main weight loss step increased and the flammability rating improved (V2 for intumescent and V0 for magnesium hydroxide reached). Moreover, fire hazard decreased (Fire Performance Index of 0.15 and 0.55; Flame Retardancy Index of 2.6 and 10.0). Referring to the morphology, full compatibility was found in the PEAL–magnesium hydroxide compound, while PEAL-intumescent appeared as a heterogeneous system
A design methodology for radial turbomachinery. Application to turbines and compressors
No full textSviluppo di una procedura per il progetto e la verifica di turbomacchine radialiDifferent design/analysis tools are combined in an automatic procedure for the design of radial turbomachinery. The algorithms developed have different complexity levels ranging from the meanline one-dimensional design tool to the fully three-dimensional Navier-Stokes based analysis. Each code gives complementary information to the designer. The codes have been written and developed by the author at DIMSET. The design procedure is developed for both radial compressors and turbines and it is proposed for the dimensioning of rotating machinery for microgasturbine power plants
Is it possible to mechanical recycle the materials of the disposable filtering masks?
No full textIn a singular period, such as during a pandemic, the use of personal protective masks can become mandatory for all citizens in many places worldwide. The most used device is the disposable mask that, inevitably, generates a substantial waste flow to send to incineration or landfill. The article examines the most diffused type of disposable face mask and identifies the characteristic of the constituent materials through morphological, chemical, physical, and thermal analyses. Based on these investigations, a mechanical recycling protocol with different approaches is proposed. Advantages and disadvantages of the different recycling solutions are discussed with considerations on necessary separation processes and other treatments. The four solutions investigated lead to a recycling index from 78 to 91% of the starting disposable mask weight. The rheological, mechanical, and thermo-mechanical properties of the final materials obtained from the different recycling approaches are compared with each other and with solutions present on the market resulting in materials potentially industrially exploitable
An Innovative Technique for the Aerodynamic Design of Turbine Profiles Using Artificial Intelligence (Invited)
No full textSviluppo di una procedura di progetto di profili aerodinamici di turbina assiale basato sull'uso di tecniche statistiche e support vector machine
Fracture Mechanics characterization of an anisotropic geomaterial
No full textArgillites are considered worldwide as potential host rock for high level radioactive waste given the low permeability and strong adsorption potential. However, the excavation of the galleries of a repository would produce a disturbed zone around the boundaries rich of new fractures which may enhance the conductivity of the rock along the gallery axis.
Several mine-by experiments have been performed in underground rock labs to investigate the features of the disturbed zone. In Mont Terri URL (Kanton Jura, Switzerland) the EZ-B experiment was specifically conceived for the measurement of excavation induced fractures around a small chamber. The host rock of the URL is a particularly compact and resistant argillite, known as the Opalinus Clay (OPA) excavated and OPA samples were subjected to fracture mechanics tests at the rock mechanics lab of IGAG-CNR in Torino, Italy. The tests aimed at the understanding aspects of the fracturing process occurring in OPA of Mont Terri, which may be considered a transversely isotropic geomaterial, whose planes of isotropy coincide with the bedding
Designing a 3D printable polypropylene-based material from after use recycled disposable masks
No full textDifferent percentages of talc were added to polypropylene deriving from pristine surgical masks in a small scale extrusion equipment to confer specific rheological and thermal properties to the resulting materials. This is not a fully satisfactory solution, thus the quantity of masks has been partially replaced by a first-use polypropylene copolymer. Two selected formulations with 35 and 50 wt.% of material deriving from pristine masks and 30 wt.% of talc have been identified as suitable for the 3D printing process.
Finally, the formulations were scaled up with a lab twin-screw extruder and by recycling sanitized after use masks to be as close as possible to field recycling conditions. The extruded pellets were processed to produce printing filament and finally validated as extrusion material for 3D printing. 3D printed tensile specimens were characterized for the mechanical properties and observed for their microstructure even comparing them with a commercial 3D printable material. For the first time is verified that a 3D printable extrusion material recycled from the disposable face masks can be obtained and shows comparable stiffness and strength to a commercial one
Analisi delle prestazioni fluidodinamiche di un compressore assiale pluristadio per impianti turbogas industriali
No full textAn assessment of the current and historical distribution of the Corncrake Crex crex in the Western Italian Alps
No full textAgricultural intensification and mechanization are major threats to farmland birds in Europe. The Corncrake Crex crex was a common and widespread species in rural landscapes in Italy, but its numbers strongly declined in most of its former range in the last half of the 20th century. Although it is a well-studied species in the Eastern Italian Alps, where most of the Italian population now occurs, there is no published information from the Western part of the range. This study aimed to describe the distribution of the Corncrake in the regions of Piedmont and Aosta Valley, taking into account both historical and recent records. Additionally, we assessed the habitat in which apparently breeding individuals were found. Overall, 78 occurrences of this species were recorded in the study region. Migrating individuals occurred at lower elevations, whilst possible breeding records were located at higher elevations in meadow-pastures and secondary grasslands. Two main current hotspots were identified in the Chisone Valley and in the valleys in the province of Cuneo, which represent the core areas for the species in Piedmont and Aosta Valley. The observation trend shows a possible recovery of the population at the regional scale, although a large-scale dedicated survey is needed to estimate population size. In 2020, the highest number of singing males in one site (5) was recorded with individuals observed above 1800 m. Conservation measures at a regional scale addressing grassland management (including mowing and grazing) might benefit the species and promote a wider recolonization of the area
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