Green corrosion inhibitors for copper and copper alloys

LAUREA MAGISTRALELo scopo del lavoro era effettuare uno studio comparativo delle prestazioni di inibitori di corrosione "verdi" per le leghe di rame nel patrimonio culturale. Sono normalmente considerati inibitori della corrosione “verdi” composti organici che non hanno effetti negativi sull’ambiente o sulla salute umana. Negli ultimi anni si è cercato di trovare alternative al benzotriazolo (BTA), che è tradizionalmente utilizzato come inibitore per le leghe di rame, per via della sua sospetta tossicità. A questo scopo una serie di inibitori a basso impatto ambientale è stata testata sia su rame che su bronzo con diverse finiture superficiali. La composizione delle diverse patine è stata caratterizzata prima dell'applicazione degli inibitori. In particolare, gli inibitori sono stati testati su rame nudo e patinato artificialmente, bronzo con patina artificiale artistica e un manufatto in bronzo invecchiato naturalmente. Otto inibitori sono stati selezionati tra quelli proposti in letteratura per lo screening iniziale: acido glutammico, L-treonina, L-cisteina, L-serina, sodio oleato, opuntia ficus oil, olio di neem e olio di argan. Le prestazioni degli inibitori sono state valutate considerando l'efficienza di inibizione fornita e la loro compatibilità estetica. Queste caratteristiche sono state valutate mediante misure elettrochimiche - resistenza lineare di polarizzazione (LPR) e spettroscopia di impedenza elettrochimica (EIS) - e misurazioni spettrofotometriche in intervallo visibile rispettivamente. Dopo il primo screening, i 4 inibitori più promettenti (sodio oleato, L-serina, olio di opuntia ficus e olio di neem) sono stati testati su una patina artificiale artistica, scelta dopo la caratterizzazione di 6 patine prodotte presso la Fonderia Artistica Battaglia di Milano. I 3 inibitori più promettenti invece (olio di neem, olio di opuntia ficus e sodio oleato) sono stati applicati e testati insieme a un rivestimento di cera commerciale R21 sulla patina naturale di una lastra in bronzo del Cimitero Monumentale di Milano. In tutte le condizioni è sempre stato utilizzato anche il BTA come riferimento. Per gli inibitori più promettenti sono state effettuate anche curve di polarizzazione al fine di avere maggiori informazioni riguardo i processi di inibizione.A comparative study of the performances of “green” corrosion inhibitors for copper alloys in cultural heritage was performed. Green corrosion inhibitors are organic compounds which are eco-friendly decreasing the risk of environmental pollution. Due to toxicity issues related to the employment of benzotriazole (BTA), the traditionally used inhibitor for copper alloys artefacts, it is indeed necessary to find an environmentally friendly and non-toxic alternative. Both copper and bronze substrate with different surface finishing were investigated. The composition and adhesion to the substrate of the different patinas were investigated before the application of the inhibitors. In particular, the inhibitors were tested on bare and artificially patinated copper, bronze with artistic artificial patina and a naturally aged bronze artefact. An initial screening of 8 inhibitors selected among those proposed in literature was carried out on bare and artificially patinated copper: glutamic acid, L-threonine, L-cysteine, L-serine, sodium oleate, opuntia ficus oil, neem oil and argan oil. The performances of the inhibitors were evaluated considering the inhibition efficiency provided and their aesthetical compatibility. These features were evaluated by means of electrochemical measurements, Linear Polarization Resistance (LPR) and Electrochemical Impedance Spectroscopy (EIS) and spectrophotometric measurements in visible range respectively. After the first screening, the most 4 promising inhibitors (sodium oleate, L-serine, opuntia ficus oil and neem oil) were tested on an artistic artificial patina, chosen after a deep characterization of 6 patinas produced at Fonderia Artistica Battaglia in Milan. While the 3 promising inhibitors (neem oil, opuntia ficus oil and sodium oleate) along with a R21 commercial wax coating were tested on the natural patina on a real artwork. In all the cases the BTA inhibitor was also tested as a reference. The most promising inhibitors were also investigated by means of polarization curves. The effect of different concentration of the inhibitors was also studied

Architecture Stood Base to Execute an event of Historical and Religious in Relief Sculpture (A Rare Relief Sculpture of a Divinely Play by Saint Tirugnana Sambaá¹…dar on Ekambaresvara Temple’s Tower of

Abstract Some of the Relief sculptures are being as lithic documents on rare History. Evidence to this; we have series of huge base reliefs carved in VaikunthaPerumal Temple of Kanchipuram. Those are being very rare master pieces of art of India; themed on History of a Dynasty. Besides, some single or loose reliefs can found some temples, those figured on some events. Some of them depicted with couple of frames or more. Some has shrunken in one frame even it for on vast story. Many of those not identified even they situated in very main places of the temples. Simply those have sighted frequently by publics some time by scholars. Though the seeing eyes even belongs to Art Historians or Historians or self-interested Writers doesn’t catch the historic or aesthetic values of the art, even though they situated in visible area as said above. In fact the great scholars too failures to this; since, that the chance is being as a gift of God thus happened in rare. Why I am saying on this is the orientation of the researched sculpture that situated in the entrance jamb of the huge Raya Gopuram of Kanchipuram Ekambareswarar Temple is noteworthy. Though of its regular and direct visibility and orientation, no any articles came so far all I Know. Therefore this paper throwsa new light probably in first time on a sculpture whichholds an historical eventand too especially with divine miracle casted by SaintThirugnanaSambandhar

Study of "green" inhibitors on copper alloy artefacts

In order to preserve the surfaces of the metallic artworks from corrosion and degradation, protective systems containing corrosion inhibitors are often applied. These systems must fulfil strict requirements of non-invasiveness from the aesthetic point of view, and shouldn't be dangerous for humans and environment. Benzotriazole (BTA) is the inhibitor usually employed for copper alloys, however it is suspected to be harmful for humans and environment. For this reason, in the last years several "green" alternatives were proposed. In this work, the performances of a selection of green inhibitors have been evaluated. They were applied on polished and artificially patinated copper, an on bronze with natural and artistic artificial patinas, in consideration of the large variability of surface conditions that can be found in cultural heritage field. Their inhibition efficiency was evaluated with electrochemical techniques, while their influence on the surfaces appearance was assessed by means of spectrophotometry in visible light

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Bitter melon (Momordica charantia L.) also known as bitter gourd, balsam pear, bitter cucumber, and African cucumber is traditionally cultivated both for food vegetable and medicine in the tropical and subtropical areas of Asia, Amazon, East Africa, and the Caribbean. Albeit such importance, it still remains as an underutilized or orphan crop and no serious efforts have been made for elucidation of its genome or its genetic improvement. M. charantia is a diploid species (2n = 2x = 22) with a 1C DNA content of 2.05 pg and an estimated physical length of 2005 Mbp/1C [1]. The genome size is more than twice the genome size of other cucurbits (880 Mbp/1C for cucumis sativus, 440 Mbp/1C for Citrullus vulgaris, 929 Mbp/1C for cucumis melo, 538 Mbp/1C cucurbita pepo) and 6.8 times the size of the Arabidopsis thaliana (0.3 pg and 295.6 Mbp/1C) genome [2,3]. In contrast to popular cucurbits such as melon, watermelon and cucumber, there is no genetic linkage map for bitter melon and obviously no information on map positions of horticulturally desirable traits, particularly those related to fruit quality and yield. Nonetheless, reports are available on the use of molecular markers including random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), simple sequence repeat (SSR), and inter-simple sequence repeat (ISSR) for assessment of genetic diversity and population stratification (4-10). Earlier observations evidenced for limited variation with regard to several fruit traits inter se the genotypes belonging to each of the two botanical varieties M. charantia var. charantia and M. charantia var. muricata but highly contrasting variation between them [7,8,10]. These two botanical varieties differ contrastingly with regard to shape, size [11], and many other qualitative and quantitative traits [7,8,10]. However, there is a need to map these traits for their precise breeding using molecular markers. For this purpose, we used an F2 mapping population derived from a cross between two parents belonging to the two botanical varieties mentioned above and a set of AFLP markers to construct the first genetic linkage map for bitter melon. We localized the genetic loci controlling five qualitative and five quantitative traits, eight of which are economically important fruit traits.Albeit extensive cultivation of bitter melon both as vegetable and medicine in many countries of Asia, Africa, and South America, no serious efforts have been made for genetic and breeding studies on this 'orphan' crop. In contrast to popular cucurbits, it lacks a genetic linkage map as required for genomic depiction and precise breeding. We report here on the construction of the first genetic linkage map of bitter melon using a set of 146 F2 progenies derived from an inter-botanical variety cross between Taiwan White, Momordica charantia var. charantia, and CBM12, M. charantia var. muricata. This map consists of 108 AFLP markers and five qualitative trait loci dispersed over 11 linkage groups spanning a total distance of 3060.7 cM. The five qualitative traits mapped include fruit color, fruit luster, fruit surface structure, stigma color, and seed color; all of which exhibited monogenic segregation except seed color which showed digenic (9:7) mode of inheritance. Besides, twelve quantitative trait loci (QTL) controlling five polygenic fruit traits including length, diameter, weight, number, and yield were detected on five linkage groups that individually explained 11.1 to 39.7% of the corresponding total phenotypic variance. This map will be useful in marker-assisted breeding of these fruit traits and future mapping of genes/QTLs controlling phytomedicines content exhibiting contrasting variation between the parents

Delayed radionecrosis of rectum presenting as soft tissue inflammation of thigh – An unusual case

AbstractThis is a case report of a 53-yr-old gentleman with soft tissue inflammation of the thigh, secondary to delayed radionecrosis of rectum. He presented with this condition, one-and-half years after he had pre-operative radiotherapy and low anterior resection for Dukes'B adenocarcinoma of rectum. In this report we emphasise the need for the clinician to be alert of this delayed side-effect of pre-operative radiotherapy and also the need for patients receiving high-dose radiotherapy to be warned of this possible complication, although it is rare