Papers by Roberto Stifanese
Environmental Science and Pollution Research, Nov 16, 2022
Nantokite (CuCl) locked inside subsurface micro-pits has been recognised as the driving force to ... more Nantokite (CuCl) locked inside subsurface micro-pits has been recognised as the driving force to the form of corrosion called bronze disease. The use of the traditional corrosion inhibitor benzotriazole is questioned because of toxicity. So there is a need for alternative conservation treatments. This work is focused on the experimental design to test the effectiveness of sodium oxalate followed by treatment with limewater to face bronze disease on outdoor bronzes. A number of foundry bronze coupons were exposed to weathering at Genoa Experimental Marine Station (GEMS) exposure site and sprayed twice a week with a 5% NaCl solution for the first 124 days. After 562 days of natural weathering, the patinas on coupons were characterised with non-destructive techniques (NDT) and the presence of nantokite was verified. We designed a workflow, as similar as possible to conservation treatments on real artworks, to test a 3% w/v sodium oxalate treatment with two different application times, with or without limewater, on the coupons. The effectiveness of the treatments was analysed by comparison of surface properties by several NDT measurements. A statistical approach and XRD measurements directly on the corroded bronze surfaces are suggested as an effective way to characterise and compare the overall behaviour of bronze disease treatments for conservation.
Environmental Science and Pollution Research
Nantokite (CuCl) locked inside subsurface micro-pits has been recognised as the driving force to ... more Nantokite (CuCl) locked inside subsurface micro-pits has been recognised as the driving force to the form of corrosion called bronze disease. The use of the traditional corrosion inhibitor benzotriazole is questioned because of toxicity. So there is a need for alternative conservation treatments. This work is focused on the experimental design to test the effectiveness of sodium oxalate followed by treatment with limewater to face bronze disease on outdoor bronzes. A number of foundry bronze coupons were exposed to weathering at Genoa Experimental Marine Station (GEMS) exposure site and sprayed twice a week with a 5% NaCl solution for the first 124 days. After 562 days of natural weathering, the patinas on coupons were characterised with non-destructive techniques (NDT) and the presence of nantokite was verified. We designed a workflow, as similar as possible to conservation treatments on real artworks, to test a 3% w/v sodium oxalate treatment with two different application times, ...
Materials and Corrosion-werkstoffe Und Korrosion, Aug 3, 2022
Metallic structures in service in seawater are protected by coupling cathodic protection and pain... more Metallic structures in service in seawater are protected by coupling cathodic protection and paints, where the former may induce disbondment of the latter. A preliminary evaluation of the cathodic disbondment risk can be made by cathodic disbondment tests (CDTs). Many CDTs use cathodic potentials as large as E < −1400 mV versus saturated calomel electrode (SCE) applied up to 90 days. Only two CDT protocols require contemporary anode isolation, current and pH monitoring, without its correction. These three aspects were considered to develop a hybrid CDT; it consisted of polarizing steel panels at −1500 mV versus SCE for 12 weeks. The chemical effects related to the anodic processes were investigated. A pH acidic shift was observed and was justified by the increasing current demand due to paint damage and brucite precipitation on the panels. The necessity of anode isolating glass to prevent chlorine chemical attack against the paints, potentially affecting the disbondment result, was verified by estimating the virtual chemical attack induced by free chlorine. In conclusion, current monitoring, pH control and anode isolation are highly suggested to correctly conduct and interpret the cathodic disbondment results when CDTs requiring large electronegative potentials are applied for long periods.
Questa settima edizione di Biochimica rende conto dei pi\uf9 recenti progressi attraverso un ling... more Questa settima edizione di Biochimica rende conto dei pi\uf9 recenti progressi attraverso un linguaggio chiaro e accessibile anche per quegli studenti che si avvicinano per la prima volta allo studio della disciplina. Le caratteristiche che, fin dalla prima edizione, rendono la Biochimica di Stryer uno dei libri di testo pi\uf9 diffusi sono: l\u2019organizzazione del testo semplice e logica: guida il lettore attraverso i processi e lo aiuta a districarsi nella complessit\ue0 dei meccanismi e delle vie metaboliche; le illustrazioni dedicate a singoli concetti: ogni immagine riesce a descrivere e spiegare un meccanismo oppure a raccontare tutto ci\uf2 che accade in una determinata via metabolica o in un dato processo biochimico senza distrarre l\u2019attenzione con un eccesso di dettagli; la rilevanza fisiologica: il testo aiuta lo studente a collegare la biochimica alla propria vita; le vie metaboliche e i processi sono presentati sempre nel loro contesto fisiologico, in modo che si ...
Gli autori David L. Nelson e Michael M. Cox sono professori di Biochimica alla University of Wisc... more Gli autori David L. Nelson e Michael M. Cox sono professori di Biochimica alla University of Wisconsin-Madison. Il libro Il Lehninger \ue8 da oltre trent\u2019anni il manuale di biochimica per antonomasia e su di esso si sono formate generazioni di studenti in tutto il mondo. Nella sesta edizione \ue8 stata profondamente aggiornata la trattazione delle tecniche genomiche e delle loro applicazioni, che hanno trasformato la nostra comprensione della biochimica. Il Capitolo 9, Tecnologie basate sull\u2019informazione contenuta nel DNA, \ue8 stato completamente riscritto e ora incorpora i pi\uf9 recenti metodi genomici, tra i quali: il sequenziamento del DNA di nuova generazione, compresi i metodi Illumina e 454; le applicazioni della genomica, compresi l\u2019utilizzo degli aplotipi per tracciare le migrazioni degli esseri umani e la filogenetica per localizzare i geni umani associati alle patologie a carattere ereditario; la tipizzazione genica forense e l\u2019utilizzo della genomica personalizzata in medicina. Tra i molti nuovi argomenti della sesta edizione vi sono inoltre: l\u2019evoluzione prebiotica, i camini vulcanici e il mondo a RNA; le proteine intrinsecamente disordinate; gli analoghi dello stato di transizione e l\u2019inibizione irreversibile; le vie della coagulazione sanguigna nel contesto della regolazione enzimatica; la distribuzione asimmetrica dei lipidi all\u2019interno del doppio strato lipidico; il ruolo della superfamiglia delle proteine BAR nella curvatura della membrana; le proteine di supporto (scaffold) e i loro ruoli regolatori; le specie reattive dell\u2019ossigeno come prodotti biologici e come molecole di segnalazione; la struttura e la funzione dell\u2019aggregato metallico di produzione dell\u2019ossigeno del PSII; la formazione e il trasporto delle lipoproteine nei mammiferi la creatina fosfato e il ruolo della creatina chinasi nel trasferimento dell\u2019ATP al citosol; i simbionti microbici presenti nell\u2019intestino e la loro influenza sul metabolismo energetico e sull\u2019adipogenesi; i nucleosomi, le loro modificazioni e il loro posizionamento e la struttura altamente ordinata della cromatina; la DNA polimerasi e la ricombinazione omologa; il caricamento della RNA polimerasi II; la natura resistente alla mutazione del codice genetico; la regolazione dell\u2019espressione genica eucariotica da parte dei miRNA; la formazione delle anse del DNA, il controllo combinatorio, il rimodellamento della cromatina e la regolazione positiva negli eucarioti; la regolazione dell\u2019inizio della trascrizione negli eucarioti; i recettori nucleari degli steroidi. Sono state inserite nuove schede su metodiche sperimentali e applicazioni mediche e aggiunti nuovi esercizi di calcolo guidati. Sono presenti inoltre esercizi di interpretazione dei dati tratti dalla letteratura scientifica e oltre 600 problemi di fine capitolo. Le risorse multimediali All\u2019indirizzo online.universita.zanichelli.it/nelson-6e sono disponibili: i test interattivi, le tecniche animate, i videoesercizi, le animazioni 3D, i grafici attivi, i tutorial molecolari, la tavola periodica interattiva, la sitografia, il glossario e le soluzioni dei problemi. Alcune di queste risorse sono espressamente richiamate nel testo. Chi acquista il libro pu\uf2 scaricare l\u2019ebook multimediale, seguendo le istruzioni presenti nel sito. Per accedere alle risorse protette \ue8 necessario registrarsi su myzanichelli.it inserendo la chiave di attivazione personale contenuta nel libro
Journal of Architectural Engineering
Journal of Bio- and Tribo-Corrosion, 2022
Metallic materials have propelled human advancements for centuries. Nevertheless, the rapid degra... more Metallic materials have propelled human advancements for centuries. Nevertheless, the rapid degradation of metallic structures in corrosive environments is inevitable. To date, the demand for metal alloys in multiple sectors, including construction and transportation, continues to escalate, with the trend it is predicted to reach beyond 250% by 2050. Thus, the need for corrosion inhibitors (CI) with qualities of high efficiency, excellent solubility, low toxicity, and inexpensiveness drive researchers to examine various possibilities. Here, we review the novelty, methods, and outputs from the latest studies on organic CI with the primary purpose of protecting mild steel and stainless steel in salt and acidic solutions. We reviewed the effectiveness, synergism impacts, and technological availability of each inhibitor and also comprehensively discussed related mechanisms of metallic corrosion and inhibition of CI.
In the field of cultural heritage several constraints about coatings to be applied have gradually... more In the field of cultural heritage several constraints about coatings to be applied have gradually been better focused over the years. Along with the need to consider aesthetics and reversibility of the restoration treatments, it is nowadays well recognised that patinas<br> and/or original historical coatings and finishes should be considered and can play an important role in protective treatments<br> behaviour. Nonetheless no standard methods have been drafted to test new coatings which can be effectively matched with<br> application on artworks. We briefly review and compare choices for copper and copper alloys coupons which can be considered as similar as possible to the metal artifacts the treatment is tested for. Some case studies is be presented to summarise the state of the art of NdT testing in this field and suggest possible developments.
Annali italiani di chirurgia, 2015
Necrosis of the NAC is a condition that penalizes patients who underwent breast reduction surgery... more Necrosis of the NAC is a condition that penalizes patients who underwent breast reduction surgery or mastopexy. Breast reduction is a widely used technique for over-sized breasts. Breast hypertrophy, in fact, can cause the onset of many issues--both aesthetical and pathological--because of the excessive weight that the breasts exert on the patient's spine. Aim and objective of our study is to suggest a systematic use of diagnostic imaging composed of pre-operative and intraoperative ultrasound with color-Doppler and pre-operative MRI. Trying to solve this problem definitively, we relied on our notions of anatomy on ten fresh cadavers, on whose twenty breasts we could make very detailed dissections. The dissections led us to conclude that, albeit with their anatomic differences, each breast was characterized by a vascular-nervous pedicle coming out from the inter-costal spaces and aimed to the blood supply to the NAC. To overcome the anatomic variations between one subject and an...
Fate and Impact of Microplastics in Marine EcosystemsFrom the Coastline to the Open Sea, 2017
Coating systems protect metal substrates from environmental corrosion attack. However, although h... more Coating systems protect metal substrates from environmental corrosion attack. However, although having good performances, the presence of specific metal ions in their composition represents a potential source of environmental contamination. The necessity to conciliate corrosion protection with environmental impact is, thereby, primary. This work was designed to study the performance of low environmental impact conversion coatings (surface pre-treatment and high-solids epoxy primer), such as those free from hexavalent chromium (Cr VI), layered on different substrates of aluminium alloy [Al 7075 (T6) unclad and Al 2024 (T3) unclad] widely used in aerospace applications. Substrate surfaces were first treated by environmentally friendly Cr-free products. Successively, on pre-treated substrates, high-solids, chromate-free epoxy primer was applied. The capability to protect substrates from corrosion phenomena was evaluated following exposure of 4 groups of samples to in situ marine atmosp...
The work proposed here is devoted to the evaluation of cathodic protection effects on some commer... more The work proposed here is devoted to the evaluation of cathodic protection effects on some commercial coatings prepared with an artificial holiday drilled in the centre of each testing panel. A new method for the determination of the cathodic disbonding behaviour of hull coatings was determined; it draws inspiration from the following standards: BS EN 10289, UNI EN and NACE TG-470. The main parameters are: synthetic sea water, replaced once a week, Pt anode, room temperature, applied potential = -1500 mV vs SCE, duration time = 13 weeks. In the cathodic side, brucite grew in areas of the thinner coatings far away from the site where the artificial defect was produced, witnessing intense coating damage. This phenomenon induces the increase of cathodic current request to maintain the fixed potential and the related anodic processes. In the anodic side, a pH drop, below 6, in times shorter than that planned for the solution renewal, was evidenced, inversely correlated to the current en...
Coating systems protect metal substrates from environmental corrosion attack. However, although h... more Coating systems protect metal substrates from environmental corrosion attack. However, although having good performances, the presence of specific metal ions in their composition represents a potential source of environmental contamination. The necessity to conciliate corrosion protection with environmental impact is, thereby, primary. This work was designed to study the performance of low environmental impact coating systems (surface pre-treatment and primer), such as those free from hexavalent chromium (Cr VI), layered on different substrates of aluminium alloy [Al 7075 (T6) unclad and Al 2024 (T3) unclad] usually utilized in aerospace applications. Substrate surfaces were first treated by environmentally friendly Cr-free products. Successively, on pre-treated substrates, Cr-free epoxy primers were applied. The capability to protect substrates from corrosion phenomena was evaluated following exposure of 4 groups of samples to in situ marine atmosphere at the Experimental Marine St...
Marine Structures
Abstract The interest in deep-sea environment is increasing both in the scientific and business c... more Abstract The interest in deep-sea environment is increasing both in the scientific and business community. Nevertheless, in situ corrosion studies are difficult to be executed due to high experimental cost and technical problems, consequently they are quite uncommon. After a summary of the scarce available literature about deep-sea environment studies on corrosion of aluminium alloys, results of an in situ exposure of Al 5083 H111, Al 6082 T6, Al 7075 T651, Al 8090 T81 alloys are presented. Specimens were exposed for 6, 12, and 18 months in deep-sea, at a depth of approximately 3350 m , off the Capo Passero (Sicily, Italy) in the KM3NeT project framework. Corrosion attack was evaluated by gravimetric weight loss measurements. Localised corrosion was investigated by using a digital camera and ImageJ software in addition to different microscopic techniques to better identify morphological/chemical details. Al 7075 T651 and Al 8090 T81 alloys performed much worse than Al 5083 H111 and Al 6082 T6 alloys. Al 6082 T6 alloy was the most resistant to corrosion, while Al 8090 T81 suffered the most relevant damage. Both Al 5083 H111 and Al 6082 T6 did not show any significant visible corrosion attack, while both Al 7075 T651 and Al 8090 T81 suffered severe localised attack. Al 8090 T81 experienced mainly pitting corrosion, while Al 7075 T651 was seriously affected by pitting, crevice, and exfoliation. The microstructural heterogeneity of both Al 7075 T651 and Al 8090 T81 alloys increases susceptibility to localised corrosion attack thus discouraging any deep-sea use of these alloys.
Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale, 2011
Uploads
Papers by Roberto Stifanese