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Strumenti e Metodologie per la Valutazione della Compatibilità Ambientale di materiali prodotti da Rifiuti Industriali per Utilizzi nel Settore delle Costruzioni
Full text linkL’attenzione verso la sostenibilità ambientale ha assunto un ruolo centrale nella definizione delle politiche industriali e delle strategie di sviluppo a livello globale. In tale contesto, l’economia circolare rappresenta un modello di riferimento capace di promuovere la riduzione degli sprechi, il recupero delle risorse e la valorizzazione di materiali derivanti da processi produttivi.
Nel contesto della transizione ecologica, il riutilizzo di materiali industriali si configura come una soluzione chiave per ridurre l’impatto ambientale delle attività edilizie. Tuttavia, la compatibilità ambientale di questi materiali deve essere rigorosamente valutata al fine di prevenire possibili effetti negativi sul suolo, sulle acque sotterranee e sull’ambiente circostante.
L’introduzione del concetto di End of Waste, introdotto dalla Direttiva Europea 2008/98/CE, rappresenta un punto di svolta nell’approccio alla gestione dei materiali di scarto, permettendo a determinati rifiuti di cessare tale qualifica e acquisire lo status di prodotto, purché siano rispettati precisi criteri di qualità e sicurezza. Allo stesso tempo, la qualificazione di materiali come sottoprodotti, conformemente all’articolo 184-bis del D.Lgs. 152/2006, offre un ulteriore strumento per favorire l’utilizzo responsabile di risorse derivanti da processi produttivi. La gestione di tali materiali nel settore delle costruzioni, tuttavia, richiede un approccio sistematico che integri valutazioni ambientali, tecniche ed economiche. Dal punto di vista della compatibilità ambientale questi requisiti non sono delineati in maniera chiara; infatti viene richiesto che “l’utilizzo della sostanza o dell’oggetto non porterà a impatti complessivi negativi sull’ambiente o sulla salute umana” nei requisiti degli EoW o che “l’ulteriore utilizzo è legale, ossia la sostanza o l’oggetto soddisfa, per l’utilizzo specifico, tutti i requisiti pertinenti riguardanti i prodotti e la protezione della salute e dell’ambiente e non porterà a impatti complessivi negativi sull’ambiente o la salute umana” in quelli dei sottoprodotti.
La presente tesi di dottorato analizza le caratteristiche di tre tipologie di materiali:
• Aggregati Riciclati (AR) da rifiuti da costruzione e demolizione (CDW): materiali inerti derivati dal trattamento e dal recupero di scarti generati durante le attività di costruzione, ristrutturazione e demolizione di edifici, infrastrutture e altre opere. Questi materiali includono principalmente calcestruzzo, mattoni, ceramiche, malte, pietre e asfalti, i quali vengono sottoposti a processi di frantumazione, vagliatura e separazione per rimuovere impurità e ottenere prodotti riutilizzabili.
• Scorie di acciaieria con forni ad arco elettrico (EAFS): Attualmente, le acciaierie impiegano procedure consolidate e standardizzate per la produzione di ghisa e acciaio. Questi processi variano in termini di materie prime utilizzate, dimensioni del forno, tempi e gestione del processo, nonché prodotti in uscita risultanti. In particolare, accanto alle materie prime (ghisa o acciaio), da questi metodi di produzione si generano sottoprodotti come le scorie siderurgiche.
• Sabbie esauste di fonderia (WFS): Le fonderie acquistano ogni anno centinaia di milioni di sabbie silicee per creare stampi e anime che conferiscono forma ai getti. Queste sabbie, dopo diversi utilizzi, diventano rifiuti che devono essere adeguatamente recuperati o smaltiti.
Il presente elaborato si propone quindi di analizzare strumenti e metodologie finalizzati alla valutazione della compatibilità ambientale di materiali derivati da processi di recupero e riutilizzo, con l’obiettivo di consentirne l’impiego sicuro ed efficace nel settore delle costruzioni, con particolare attenzione alle applicazioni non legate (in cui non è presente legante, come cemento o bitume).The growing focus on environmental sustainability has assumed a central role in the definition of industrial policies and development strategies at the global level. In this context, the circular economy serves as a reference model capable of promoting waste reduction, resource recovery, and the valorization of materials originating from production processes.
Within the framework of ecological transition, the reuse of industrial materials emerges as a key strategy to reduce the environmental impact of construction activities. However, the environmental compatibility of these materials must be rigorously evaluated in order to prevent potential negative effects on soil, groundwater, and the surrounding environment.
The introduction of the End of Waste concept (European Directive 2008/98/EC) marks a turning point in the approach to waste management, allowing certain waste streams to cease being classified as waste and instead be recognized as products, provided that they meet specific quality and safety criteria. Simultaneously, the classification of materials as by-products, under Article 184-bis of Legislative Decree 152/2006, offers an additional instrument for fostering the responsible use of resources generated by production processes. Nevertheless, the management of such materials in the construction sector requires a systematic approach integrating environmental, technical, and economic assessments. From the perspective of environmental compatibility, the requirements are not clearly delineated; in fact, the EoW criteria specify that “the use of the substance or object will not lead to overall negative impacts on the environment or human health,” while by-product regulations require that “its further use is lawful, meaning that the substance or object meets, for the specific use, all pertinent product, health, and environmental protection requirements and will not lead to overall negative impacts on the environment or human health.”
This doctoral thesis examines the characteristics of three types of materials:
Recycled Aggregates (RA) from Construction and Demolition Waste (CDW): These are inert materials obtained through the treatment and recovery of debris generated from construction, renovation, and demolition activities involving buildings, infrastructure, and other works. They primarily include concrete, bricks, ceramics, mortars, stones, and asphalt, which undergo crushing, screening, and separation processes to remove impurities and produce reusable materials.
Electric Arc Furnace Steel Slag (EAFS): Steel mills currently employ standardized and consolidated procedures for producing pig iron and steel. These processes differ with respect to raw materials used, furnace size, processing duration, and process management, as well as the resulting outputs. In particular, alongside primary raw materials (pig iron or steel), these methods generate by-products such as steelmaking slag.
Waste Foundry Sand (WFS): Each year, foundries purchase hundreds of millions of tons of silica sand to form molds and cores that give shape to cast components. After multiple uses, these sands become waste and must be appropriately recovered or disposed of.
This dissertation therefore aims to analyze the tools and methodologies employed for assessing the environmental compatibility of materials derived from recovery and reuse processes, with the goal of enabling their safe and effective utilization in the construction sector, especially in unbound applications (i.e., those that do not incorporate binders such as cement or bitumen)
Ecotoxicological assessment of waste foundry sands and the application of different classification systems
Full text linkThe application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty-five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457-2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348-3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single-organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost-effective and time-efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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