Search results for " recycling"
showing 10 items of 131 documents
Layered lower crust and mantle reflectivity as imaged by a re-processed crustal seismic profile from Sicily in the central Mediterranean
2015
Abstract Though Sicily is a key area for understanding the central Mediterranean tectonics, a number of questions on its dynamics remains open due to the lack of detailed data on the lithospheric structure. Deep reflectivity images of the African lithosphere, beneath Sicily, have been derived from the re-processing of the crustal seismic reflection stack (SI.RI.PRO. Project). Of specific interest was the imaging, beneath central-southern Sicily, of a thinned crust with a reflective, “layered” pattern for the lower crust that differs from the one, thicker and sub-transparent, of the northern-central sector. Brittle deformation in the upper crystalline crust along a low-angle normal fault and…
Architectural technologies for life environment: Spent coffee ground reuse in lime-based mortars. A preliminary assessment for innovative green therm…
2022
Spent coffee ground, the residue obtained from the brewing process, is the primary unavoidable (inedible) waste from the coffee consumption. As coffee production and beverage consumption are increasing worldwide, a more sustainable waste management is required since the usual disposal in landfill is a liability to both humans and the environment. This paper is aimed at showing a possible alternative reuse of coffee ground wastes in novel green building materials intended for thermo-plastering applications in construction, in a circular economy context. Coffee waste was used in various percentages (up to 17.5%) to assess the engineering performance of the produced bio-composite mortars. The …
Application of textile fibres from tire recycling in asphalt mixtures
2022
The tire rubber obtained from end-of-life car and truck tires has been successfully recycled, among other applications, in the asphalt industry by providing a mean to get asphalt mixtures with superior performance. Textile fibres are another component derived from tire recycling typically disposed of in landfills or used in energetic valorisation. This paper wants to re-ignite interest in this secondary product by evaluating its use as a valuable resource in asphalt mixtures. Indirect tensile tests, dynamic modulus, fatigue resistance, and permanent deformation tests were performed on a series of AC14 asphalt mixtures manufactured with two binders, namely 50/70 and 35/50 pen, using several …
Slow pyrolysis of an LDPE/PP mixture: Kinetics and process performance
2021
Abstract High- and low-density polyethylene (HDPE and LDPE) and polypropylene (PP) are the most common polymers among plastic waste as they have multiple commercial applications. This study focused on thermal degradation characteristics and kinetic of a plastic mixture with a composition of 92.5 wt% LDPE and 7.5% PP. Thermal decomposition characteristics of the plastic mixture was analysed through thermo-gravimetric analysis (TGA). The overall kinetic of the process was studied using the modified Coats−Redfern method and the Ozawa-Flynn-Wall (OFW) method. The apparent activation energy (E) and pre-exponential factor (A) obtained were 316.0 kJ/mol; 8.09E+21 min−1 and 311.5 kJ/mol; 4.35E+21 m…
On the projected increase of Sahel rainfall during the late rainy season
2016
Thirteen CMIP5 models are used to analyse changes in climate over the West African monsoon region between the near future (2031–2070 under the RCP4.5 emission scenario), and a control period (1960–1999 under the historical emission scenario), with a focus on the late rainy season. The monsoon circulation is projected to strengthen and to shift northward leading to more rainfall during the Sahelian season. The results show an increase of the Rainfall amounts in September–October and a delay in the monsoon withdrawal. The increased moisture that fuels the rainfall anomalies is associated with an increase in moisture flux convergence and with local moisture recycling. The moisture transport do…
Toward the Decarbonization of Plastic: Monopolymer Blend of Virgin and Recycled Bio-Based, Biodegradable Polymer.
2022
Decarbonization of plastics is based on two main pillars: bio-based polymers and recycling. Mechanical recycling of biodegradable polymers could improve the social, economic and environmental impact of the use of these materials. In this regard, the aim of this study was to investigate whether concentrations of the same recycled biopolymer could significantly affect the rheological and mechanical properties of biodegradable monopolymer blends. Monopolymer blends are blends made of the same polymers, virgin and recycled. A sample of commercially available biodegradable blend was reprocessed in a single-screw extruder until two extrusion cycles were completed. These samples were exposed to gr…
Multi-layered, covalently supported ionic liquid phase (mlc-SILP) as highly cross-linked support for recyclable palladium catalysts for the suzuki re…
2011
The reaction between an excess of 1,4-bis(3-vinylimidazolium-1-yl) bromide and a mercaptopropyl-modified amorphous silica gel or ordered mesoporous silica SBA-15 in the presence of azobisisobutyronitrile (AIBN) afforded new materials, which have a high loading of imidazolium moieties. These materials, which contain a highly cross-linked polymeric network, have been denoted as multi-layered, covalently supported ionic liquid phase (mlc-SILP) and have been used as support for palladium catalysts containing a high loading of the metal (10 wt%). Such materials were characterized by several techniques (13C magic angle spinning nuclear magnetic resonance, the Brunauer–Emmett–Teller technique, sma…
Recycling of dry and wet polyamide 6
2002
Recycling of polycondensation polymers can give rise to secondary materials with good mechanical properties only if a careful drying is carried out before the melt reprocessing operations. The presence of humidity provokes the hydrolytic chain scission of the macromolecules and the consequent decrease of molecular weight and properties. In this work, the drying step was substituted by the addition of an antioxidant that is able to protect the macromolecules because it is the autioxidant is more prone to hydrolysis, thus removing the water from the melt. The mechanical properties of polyamide 6 reprocessed more times in wet conditions and in the presence of this stabilizer are even better th…
Characterization of monopolymer blend of virgin and recycled polyamide 6
2002
It is a common industrial practice to blend virgin polymer with the same recycled polymer coming from plastic scraps that, in general, has not undergone relevant degradation. In this work, the characteristics of blends of virgin and recycled polyamide have been considered by changing the amount of recycled polymer and the presence of humidity and a stabilizer. Neither dry nor wet stabilized recycled polyamide samples show significant variations of the molecular weight, but the melt Newtonian viscosity of the blends are slightly different from that predicted by an additive rule, despite the same chemical nature of the two components. This holds true even more for the humid unstabilized sampl…
Melt stabilization of wet polyamide 6
2002
Abstract Melt processing of polycondensate polymers must be carried out after careful drying in order to avoid any hydrolytic chain scission caused by the presence of water or other small molecules. In this work, the effect of two different antioxidants on the processing and flow properties of a polyamide 6 sample not dried before processing operations has been studied. One of these stabilizers seems to protect the wet polymer from hydrolytic chain scission. This action has been interpreted considering that the stabilizer hydrolyses instead of the polyamide macromolecules.