12064 research outputs found
Sort by
Black Plastic Waste Classification by Laser-Induced Fluorescence Technique Combined with Machine Learning Approaches
Get PDFSensor-based sorting devices commonly used in plastic recycling plants, mainly working in the near infrared range (NIR), are unable to identify black plastics, due to their low spectral reflectance. The aim of this work was to investigate the potentialities offered by laser-induced fluorescence (LIF) technique (spectral range 270–750 nm) for the identification of black polymers inside a plastic waste stream, thus allowing the possibility to build efficient sorting strategies to be applied in recycling plants. Representative samples of black plastics collected among the most utilized in household packaging were selected, constituted by four different types of polymers, i.e., expanded polystyrene (EPS), polystyrene (PS), polypropylene (PP) and high-density polyethylene (HDPE). The acquired LIF spectra were processed using multivariate approaches in order to optimize polymer classification. The developed hierarchical—partial least square-discriminant analysis (Hi-PLS-DA) classification model, showed excellent performances, confirmed by the values of sensitivity and specificity values in prediction, being equal to 1. The correctness of classification obtained by LIF was confirmed by the application of Fourier Transform Infrared spectroscopy (FTIR) on the same samples. The achieved results demonstrated the potential of LIF technique combined with a machine learning approach as sorting/quality control tool of black polymers in recycling plants. Graphical Abstract: (Figure presented.
A bacterial formula with native strains as alternative to chemical fertiliser for tomato crop
No full textGlobal tomato productivity is threatened by biotic and abiotic stressors. To support and guarantee an adequate yield of tomato crops, agricultural practices have been based on the intensive use of fertilisers with negative impacts on the environment. This study presents a simple and effective strategy of functional bioaugmentation, suitable for different varieties, to replace chemical fertilisation. A tailored microbial formula composed by eight indigenous strains (including the genera Delftia, Pseudomonas, Paenarthrobacter, Phyllobacterium, Bacillus, and Acinetobacter) was developed as biofertilizer. Strains were selected from native soil for their plant growth-promoting (PGP) functions, and combined respecting the taxonomic composition of the original PGP heterotrophic community structure. The effect of the bio-fertilisation vs chemical fertilisation was tested in three successive field trials in the company greenhouse, with different tomato varieties (Camone, Oblungo, Cherry). When bio-fertilisation was applied only twice during the Camone’s life cycle, tomato yield was significantly reduced (0.8 vs 2.1 kg per plant, p = 0.0003). However, monthly inoculation during plant growth led to a fruit yield comparable to that obtained with chemical fertilisers (about 1.5 kg per plant for Oblungo, and about 2 kg per plant for Cherry variety, p = 0.9999). Bio-fertilization did not significantly affect plant height; only during the last growing period of the Cherry variety, a significantly higher average plant height (p < 0.0001) was observed with chemical fertiliser. The results indicate that a knowledge-based bacterial formula and monthly inoculation during the plant growth can be a successful bio-fertilisation strategy. These findings may pave the way towards more sustainable tomato production, since farming practices are becoming increasingly crucial, in accordance with Agenda 2030 and the UE “Farm to Fork” strategy
Structural, Electronic and Vibrational Properties of B24N24 Nanocapsules: Novel Anodes for Magnesium Batteries
Get PDFWe report on DFT-TDDFT studies of the structural, electronic and vibrational properties of (Formula presented.) nanocapsules and the effect of encapsulation of homonuclear diatomic halogens ((Formula presented.), (Formula presented.) and (Formula presented.)) and chalcogens ((Formula presented.) and (Formula presented.)) on the interaction of the (Formula presented.) nanocapsules with the divalent magnesium cation. In particular, to foretell whether these BN nanostructures could be proper negative electrodes for magnesium-ion batteries, the structural, vibrational and electronic properties, as well as the interaction energy and the cell voltage, which is important for applications, have been computed for each system, highlighting their differences and similarities. The encapsulation of halogen and chalcogen diatomic molecules increases the cell voltage, with an effect enhanced down groups 16 and 17 of the periodic table, leading to better performing anodes and fulfilling a remarkable cell voltage of 3.61 V for the iodine-encapsulated system
Assessment of the Electrostatic Field Uniformity Within an Electrospinning Device
No full textThe analysis carried out made it possible to evaluate the electrostatic field in an electrospinning device by means of a Comsol finite element model. The study focuses on the main factors affecting the generation of nanofibers and on the uniformity of the electrostatic field over the collector. In particular, the behaviour of the electrostatic field vector close to the needle and along the edges of the collector was assessed. Finally, the electric field at several points on the collector surface was computed in Comsol. The obtained data were processed in Matlab to assess the variation of the electric field along the x; -and y -directions. The model results allow to explain interesting aspects arising from the use of the machine
Problems and Requirements for the Robotic Disassembly of Lithium-Ion Batteries in the Automotive Industry
No full textThis paper discusses challenges behind automation and human-robot cooperation in industrial disassembly tasks with a case study on lithium-ion car batteries. To numerically characterize this application, the performance of a robot and a human on an unscrewing task are reported and compared. The advantages and disadvantages of both options are discussed by proposing and analyzing a new performance criterion that successfully gives indications on human-robot task distribution
Towards a Service Marketplace to Empower Circular Economy Transition: An Example Application in the Supply Chain of Textile Industry
No full textThe environmental impact of the textile industry is driving a shift towards circular economy (CE) practices. The EU’s 2022 strategy mandates the Digital Product Passport (DPP) for textiles, which requires environmental and circularity data along the value chain. To comply with DPP, it is necessary to use digital services for CE in supply chains to assess the environmental impact of textile products. CE services require addressing interoperability issues and facilitating data exchange between these CE services used by different companies for their individual products. Although various CE services are available as commercial off-the-shelf products, they are often provided with a generic data model for a specific product and significant effort is required by SMEs to address customisation. Existing service marketplaces are either not domain specific or do not facilitate easy (re-)use and adoption of these CE services. This paper proposes a marketplace to address this challenge. It connects solution providers offering CE services with SMEs seeking solutions. The marketplace implements Software as a Service (SaaS) and provides public APIs and domain & product specific data connectors to facilitate data exchange and interoperability between individual services from companies and CE services in the marketplace. This will minimise the effort required to discover, deploy and use CE services within SMEs, and facilitate the (re)use of CE services across different products. With this, the marketplace aims to promote sustainability and traceability in the circular economy of the textile sector, which is shown for the Preferential Certificate of Origin
First Phase Passive Heat Removal Facility (PHRF) Experiments for Westinghouse LFR
No full textThe Westinghouse Lead Fast Reactor (LFR) is a 450 MWe class, lead-cooled, fast neutron spectrum, pool-type reactor with passive safety systems. Its mission is to best complement Light Water Reactors (LWR) in the mid- to long-term by providing enhanced application versatility for global markets while targeting cost-effective deployment. The passive heat removal system (PHRS) is the emergency decay heat removal system of this advanced plant. A distinctive feature of the PHRS that it is always on, and does not require any operator intervention, signals of intelligence or moving is parts for the actuation and operation, consistent with the IAEA passive safety category B. The system initially removes heat through water boiling and subsequently transitions to (indefinite) air cooling. To assess the performance of the PHRS and provide experimental data for the verification and validation of modeling and simulation tools, the passive heat removal facility (PHRF) has been built at the Ansaldo Nuclear’s site in Wolverhampton, UK, with the support from the United Kingdom Government and international partners. The PHRF is a full-height separate effects test facility that follows the power-to-volume scaling rule to maximize its prototypicality. The test matrix of the first phase of testing included both air cooling tests and transition tests from water cooling to air cooling. A significant amount of experimental data has been generated in the first phase of testing, confirming the performance of the PHRS both in air cooling mode and during the transition from water cooling to air cooling
Energy Communities as Enablers of Local Token Economies: An Exploratory Analysis in Italy
No full textIn the dynamic landscape of Local Energy Communities (LECs), blockchain technologies emerge as valuable tools for tracking and managing integrated energy flows. Simultaneously, blockchain facilitates the establishment of Token Economies (TEs), fostering the growth of local economies and facilitating the management of local exchanges of products and services. The potential benefits of using blockchain in both LECs and TEs applications underscores the importance of exploring their collaborative development. This study pioneers the examination of an LEC supported by a TE within the Italian context. The study models the operations of an LTE and conducts economic sustainability analyses using a bespoke mathematical model; this research offers valuable insights into the determinants of the project's success. Moreover, it quantifies the financial backing required by an LTE to nurture the project's development
Cluster Analysis of Masonry Types to Analyze the Energy Performance of Historic Buildings: Preliminary Results
No full textThe study discussed in this paper is part of a research, which applies the method of masonry typology to the historic building stock of Sicily. The research is being carried out on a set of local contexts, currently 14 villages and small towns. The general aim is building a database of mechanical and thermal data specific to historic masonry and verifying if correction factors, based on the construction features of local masonry types, may improve the reliability of calculated U-value. The cluster analysis described in this paper was performed to examine the technical data collected for each type, in relation to the thermal modeling of historic stonewalls. In this cluster analysis, each masonry type was treated as an observation, whose quantitative and qualitative variables are the construction details of the local masonry types. A non-hierarchical method was applied through the functions Daisy and PAM in software R. The clustering structure is made of two clusters, and though featured by the rate of reliability SC = 0.33, it provides relevant indications about the construction characteristics to select as parameters in the thermal models of local masonry types. The paper discusses these preliminary findings and their further development
SIMMER-III CODE SIMULATION OF HIGH-PRESSURE WATER-LEAD INTERACTION IN WESTINGHOUSE'S LEWIN TEST FACILITY
No full textThe Lead-cooled Fast Reactor (LFR) is one of the six advanced reactor system types selected in the Generation-IV (Gen IV) program. Westinghouse (WEC) is developing a highly simplified, passively safe, medium-size, economic Gen-IV LFR as its next-generation utility-scale nuclear power plant. Designed as a pool-type reactor, the Westinghouse LFR has all primary components located inside the reactor vessel (RV). The heat transfer from the primary coolant to the secondary side is accomplished through three primary heat exchangers (PHEs). The PHE failure is one of the safety events considered in designing the Westinghouse LFR. Therefore, the transient behavior of the molten lead pool following PHE failure should be investigated to evaluate its consequences and to adopt effective mitigation measures. Based on the secondary system considered in the WEC LFR conceptual design, a high-pressure water injection into molten lead is considered for the characterization of coolant-coolant interaction (CCI) during a postulated PHE failure accident scenario. In the framework of the collaboration between Westinghouse and ENEA, a separate effect testing (SET) facility named LEWIN (LEad-to-Water INteraction) was designed and built, with the aim of identifying and quantifying the main phenomena that occur during the high-pressure water injection into molten lead. To support the conceptual design and experimental pre-test phase, the SIMMER-III (S-III) computer code was used to model the interaction vessel, the injection line, and the dump line. The choice of this code is justified by its distinctive fluid-dynamics features: it uses two-dimensional meshes to simulate a multivelocity field with multiphase and multicomponent materials. However, since the original version of the S-III code cannot simulate two different types of coolant at the same time, code modifications have been introduced to enable modeling of the lead-water interaction. This paper aims to assess the capability of SIMMER in simulating the main phenomena expected to take place during the experimental transients in LEWIN, and hence to illustrate the pioneering role the code can play, especially in studying the phase change phenomenology in lead-water thermal-hydraulics systems. The simulation results show the flashing of the water injected into the molten lead, the growth of water vapor bubbles in the lead pool, the lead pool swelling, and the lead sloshing motion. The pressure peak, onset of a choked flow, and pressurization of the cover gas region can be observed as well. This activity has also the objective of supporting a systematic validation and verification (V&V) program for the SIMMER code assessment based on test problems involving lead, lead-bismuth eutectic alloy, and water systems, to advance the code as a next-generation standard tool for LFR safety analysis