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Povzetek: Bronze surfaces, whether bare or patinated, tend to change when exposed to an outdoor atmosphere. Art made of bronze which is exposed to the outdoors is usually artificially patinated. This patina changes when exposed to rain, especially in polluted rain, where sulphuric, nitric or carbonic acids are present. In order to gain optimal protection of different patinas and consequently reduce the patina changes over the time different protection systems were developed, tested and tailored. Three types of patina (brown, green sulphate, and green persulphate) were prepared, protected and subsequently studied. The protections were based on two coatings (i) fluoropolymer based coating (FA-MS) and (ii) newly developed fluoropolymer based coating with addition of mercaptopropyl groups, named as alternative fluoropolymer coating (FA-MS-SH). Both the pure patinas applied on bronze surfaces as well as the bare bronze were electrochemically tested, first unprotected and then following the application of two different types of protection. After the protection was applied to the pa- tinas, the change in colour was defined. Different techniques were utilised in order to define the morphology and structure of the patinas, as well as the change in colour following application of the coating. It was shown that a fluoropolymer coating (FA-MS) provided the most efficient protection to bare bronze and the sulphate patina, while a newly proposed alternative fluoropolymer coating (FA-MS-SH) offered good protection to bare and brown patinated bronze. A mechanism for the protection of bare and patinated bronze was suggested.
Ključne besede: bronze, patina, protection
Objavljeno v DiRROS: 17.07.2023; Ogledov: 325; Prenosov: 185
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Objavljeno v DiRROS: 23.06.2023; Ogledov: 486; Prenosov: 198
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Povzetek: The evolution of alluvial megafans has mainly been investigated in unconfined settings; however, at the boundary of these large depositional systems, the development of fluvial channels can be affected by structural constraints with regional extent. Here we present the study of the eastern sector of the megafan of Isonzo River, in the Gulf of Trieste, where this system fed through the southern Alps is constrained by the Karst and Istria cliffs. Although this area is now submerged under the northern Adriatic Sea, stratigraphy from seismo-acoustic profiles, drill cores and multi-beam bathymetry allows us to reconstruct the paleochannel system of the Isonzo River in detail, which was likely active within the period of 21–17.5 ka cal BP, at the end of LGM. This was reconstructed for over 50 km and currently represents the longest abandoned fluvial channel in the Mediterranean seabed. The occurrence of the mountain fringe and competition with nearby alluvial systems forced the paleochannel to follow the present coastline and conditioned the slope of its thalweg to decrease almost to null, resulting the transformation from the megafan to the undifferentiated alluvial plain.
Ključne besede: marine geology, CHIRP, stratigraphy, bathymetry, last glacial maximum, adriatic sea
Objavljeno v DiRROS: 31.05.2023; Ogledov: 313; Prenosov: 107
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Povzetek: When bronze or artificially patinated bronze is exposed to an outdoor environment that contains aggressive ions such as sulphates, nitrates, and carbonates, the surface of the bronze changes its appearance due to the formation of corrosion products on the surface. Research is being conducted on versatile protective measures that can be used to protect the surface from these changes. A recently synthesised fluoropolymer-based coating with mercaptopropyl groups, i.e. a 3-component fluoropolymer coating FA-MS-SH (silane-modified poly methylmethacrylate (MS) with added mercaptopropyltrimethoxy silane (SH) and a fluoroacrylate (FA)) was explored in detail in this work where its protective mechanism on sulphide patinated bronze was investigated. Electrochemical tests were conducted on the sulphide patinated bronze with and without the 3-component coating FA-MS-SH. Furthermore, FA, MS and SH alone and various combinations and concentrations of FA-MS were studied in order to determine the protective effect and properties of each component. Colour change and contact angle measurements were also defined. FIB-SEM measurements and GCIB-XPS depth profiles were carried out to study surface bonding with the sulphide patina in detail. A mechanism for the protection of sulphide patinated bronze was presented through the use of a multianalytical tool approach. It was shown that FA physisorbed on the patinated surface, while MS and blends of the components chemisorbed on the layer of sulphide patinated bronze, also resulting in the surface being efficiently protected from corrosion processes.
Ključne besede: bronze, protection, brown patina, fluoropolymer coating
Objavljeno v DiRROS: 31.05.2023; Ogledov: 372; Prenosov: 208
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Povzetek: Bolniki z napredovalim malignim melanomom s prisotno BRAF mutacijo tumorskih celic so kandidati za tarčno zdravljenje z BRAF in MEK zaviralci. Pričujoči klinični primer nam predstavi bolnico z napredovalim malignim melanomom s prisotno BRAF mutacijo, ki se je leta 2015 pričela zdraviti z BRAF zaviralcem (vemurafenibom), s katerim je bila dosežena nekajletna remisija bolezni. Ob napredovanju bolezni je bilo uvedeno zdravljenje z zaviralcem imunskih nadzornih točk (ZINT) s pembrolizumabom. Po dveh letih je bilo zdravljenje zaključeno, saj je bila dosežena popolna metabolična in klinična remisija bolezni. V fazi sledenja je bil na novo-ugotovljen solitaren zasevek v možganih, ki je bil odstranjen, ležišče zasevka je bilo obsevano. Uvedeno je bilo zdravljenje s kombinacijo nivolumaba ter ipilimumaba, ki je bilo predčasno ukinjeno zaradi imunsko pogojenih nezaželenih stranskih učinkov. Do sedaj ni dokazanega napredovanja bolezni, vendar je v prihodnosti pričakovati napredovanje v osnovi že napredovale bolezni. Pojavlja se vprašanje nadaljnjega zdravljenja.
Ključne besede: rak kože, melanom, sistemsko zdravljenje
Objavljeno v DiRROS: 17.05.2023; Ogledov: 355; Prenosov: 127
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