1,720,962 research outputs found
Life Cycle Assessment of an Innovative Process for PVC Cables Waste Recycling
No full textCable recycling is an important source of high-grade secondary copper. Unfortunately, for every kg of copper produced, the cable recycling process also creates some 2 kg of residue: a complex mixture of PVC insulation, ill-liberated cable parts, very fine copper wire and a minor amount of other materials. This paper investigates two scenarios for this residue in terms of Life Cycle Assessment: land filling versus an innovative process that recycles over 90 mass% of the residue by means of a precise separation on density into a clean PVC fraction and a fine copper product. In order to compare the two scenarios and account for the quality issue of recycled materials, the land filling option is extended with the production of copper and PVC from primary resources, in quantities that represent the same market value as the recycled materials in the recycling scenario. The result of the analysis indicates that, despite this conservative approach, the recycling scenario reduces the relevant impacts by a factor of ten with respect to land filling
Upgrading of PVC rich wastes by magnetic density separation and hyperspectral imaging quality control
No full textPolyvinylchloride (PVC) is one of the most produced polymers in Europe, with a share of 11% in terms of mass (8 million tons) of total polymer consumption, but in 2010 only 5% of the total PVC production came from recycled materials, where other polymer recycling achieves a level of 15% on average. In order to find an innovative process to extract PVC from window frames waste, a combination of two innovative technologies was tested: magnetic density separation (MDS) and hyperspectral imaging (HSI). By its nature, MDS is. a flexible high precision density separation technology that is applicable to any mixture of polymers and contaminants with non-overlapping densities. As PVC has a very distinctive high density, this technology was tested to obtain high-grade PVC pre-concentrates from window frame waste. HSI was used to perform a quality control of the products obtained by MDS showing that PVC was clearly discriminated from unwanted rubber particles of different colors. The results showed that the combined application of MDS and HSI techniques allowed to separate and to check the purity of PVC from window frame waste
Upgrading of PVC rich wastes with the combination of magnetic density separation and hyperspectral imaging analysis
No full textPolyvinylchloride (PVC) is one of the most produced polymers in Europe, with a share of 11% in terms of mass (8 Million tonnes) of total polymer consumption, but in 2010 only 5% of the total PVC production was from recycled materials, where other polymer recycling achieves a level of 15% on average. In order to find an innovative process to extract PVC from window frames waste, a combination of two recent technologies has been tested: magnetic density separation (MDS) and hyperspectral imaging (HSI) analysis. By its nature, MDS is a flexible high precision density separation that is applicable to any mixture of polymers and contaminants with non-overlapping densities. As PVC has a very distinctive high density, this technology can be used to make high-grade PVC pre-concentrates from many PVC-rich waste streams. Considering that PVC has a characteristic spectral signature in the NIR range, it can be clearly discriminated from other polymers and contaminants by HSI. The results showed that the combined application of MDS and HSI techniques allowed to separate and identify PVC from window frame waste
Quality control in the recycling stream of PVC cable waste by hyperspectral imaging analysis
No full textThe reduction of EOL concrete disposal in landfills, together with a lower exploitation of primary raw materials, generates a strong interest to develop, set-up and apply innovative technologies to maximize Construction and Demolition Waste (C&DW) conversion into useful secondary raw materials. Such a goal can be reached starting from a punctual in-situ efficient characterization of the objects to dismantle in order to develop demolition actions aimed to set up innovative mechanical-physical processes to recover the different materials and products to recycle. In this paper an innovative recycling-oriented characterization strategy based on HyperSpectral Imaging (HSI) is described in order to identify aggregates and mortar in drill core samples from end-of-life concrete. To reach this goal, concrete drill cores from a demolition site were systematically investigated by HSI in the short wave infrared field (1000-2500 nm). Results obtained by the adoption of the HSI approach showed as this technology can be successfully applied to analyze quality and characteristics of C& DW before dismantling and as final product to re-utilise after demolition-milling-classification actions. The proposed technique and the related recognition logics, through the spectral signature detection of finite physical domains (i.e. concrete slice and/or particle) of different nature and composition, allows; i) to develop characterization procedures able to quantitatively assess end-of-life concrete compositional/textural characteristics and ii) to set up innovative sorting strategies to qualify the different materials constituting drill core samples
Standardization of solid recovered fuels through gravity separation and chemical based imaging techniques
Get PDFThe European politics is addressed, in their last years, more and more towards the abolition of landfills and oriented to verify the possibility to improve their recovery through actions of recycling, composting and energy production. Currently the European Directive 2008/98/EC, through the principle of End of Waste (EoW), is driving the utilization of new methods of waste processing in order to transform them it into a new "renewable" product. The post-consumer plastics resulting from packaging account for about 60% of total plastics waste (i.e. 23 million tons) produced in Europe. The high quality Solid Recovered Fuel (SRF) is a partial solution to the problem of waste and landfill management, becoming integral and essential in the closure of the waste cycle, representing one of virtuous processes for the treatment and recovery of waste. The application of recycling strategies, finalised to polymers recovery, can thus represent an important opportunity to reduce: i) not renewable raw materials utilization (i.e. oil), ii) carbon dioxide emissions and iii) the amount of plastic waste disposed-off. Aim of this work is to study the possibility offered by the integrated utilization of Chemical Imaging (CI) based techniques in order to obtain a good quality SRF characterized by a low content of PVC derived packaging to be used for the production of thermal energy. Packaging "final waste", in fact, is usually characterized by the presence of PolyVinyl Chloride (PVC). Therefore the association of a specific gravity separation architecture with the CI based sensing units, could strongly improve the quality of "final waste" fraction as resulting from classical recycling processes based on milling, classification and density separation. The presence of PVC, in fact, has a negative influence on the combustion and heat recovery of these products due to the production of dioxins and furans. The utilization of the proposed combined approach (i.e. gravity and CI based) could contribute to obtain a SRF characterized by a very low PVC content, thus allowing to certify SRF according to UNI EN 15359:2011 and to correctly utilise it for thermal energy production
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Gravity separation and chemical imaging based tecniques for plastic packaging final waste recovery
No full textPlastic polymers are characterized by a high calorific value and the post-consumer plastic waste can be considered, in many cases, as a typical secondary solid fuels according to the European Commission directive on End of Waste (EoW). In Europe the practice of incineration is considered one of the solutions for the disposal of waste, for the recovery of energy and, as a consequence, for the reduction of waste sent to landfill. A full characterization of these products represents the first step to profitably and correctly utilize them. Several techniques have been thus investigated to characterize and separate post-consumer plastic packaging waste in order to reach the previous mentioned goal, that is: gravity separation (i.e. Reflux Classifier), FT-IR spectroscopy, HyperSpectral NIR Imaging based techniques and calorimetric test. The study demonstrated as the proposed separation technique and the HyperSpectral NIR Imaging approach applied for the removal of the PVC fraction from plastic waste and the further quality control of the resulting products, can be profitably utilised to set up analytical/control strategies finalized to obtain a low content of PVC in the final Solid Recovered Fuel (SRF)
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