1. Activation and repassivation of stainless steels in artificial brines as a function of pHEmir Mujanović, Bojan Zajec, Tadeja Kosec, Andraž Legat, Stefan Hönig, Gerald Zehethofer, Gregor Mori, 2019, izvirni znanstveni članek Povzetek: When planning oil wells with stainless steel components, two possible reasons for depassivation have to be considered-chemical depassivation caused by acidizing jobs and mechanical depassivation caused by various tools and hard particles. The study explores conditions causing chemical activation of investigated steels and circumstances under which repassivation occurs after activation. The main focus of the study is to determine, how quickly various steels can repassivate under different conditions and to find pH values where repassivation will occur after depassivation. The investigated steels were ferritic (martensitic or bainitic) in the cases of 13Cr, 13Cr6Ni2Mo, and 17Cr4Ni2Mo, austenitic in the case of 17Cr12Ni2Mo, and duplex (austenitic and ferritic) in the case of 22Cr5Ni3Mo. Potentiodynamic experiments were employed to obtain electrochemical properties of investigated steels, followed by immersion tests to find ultimate conditions, where the steels still retain their passivity. After obtaining this information, scratch tests were performed to study the repassivation kinetics. It was found that repassivation times are similar for nearly all investigated steels independent of their chemical composition and microstructure. Ključne besede: stainless steels, activation, repassivation Objavljeno v DiRROS: 21.11.2023; Ogledov: 231; Prenosov: 108 Celotno besedilo (4,47 MB) Gradivo ima več datotek! Več... |
2. Depassivation and repassivation of stainless steels by stepwise pH changeEmir Mujanović, Bojan Zajec, Andraž Legat, Tadeja Kosec, Janez Kovač, Gregor Mori, Stefan Hönig, Gerald Zehethofer, 2020, izvirni znanstveni članek Povzetek: Immersion tests with different stainless steels have been performed, while the pH was stepwise decreased and then increased again. During 8.5-day exposure, the depassivation and repassivation pH values as a function of pitting resistance equivalent number were determined. There is always a gap between both pH values (depassivation and repassivation), indicating that for every steel, there are conditions where an existing passive layer can be maintained but cannot be rebuilt after depassivation. In such environments, the passive layer is thicker, consisting mainly of molybdenum and iron rich oxides, while chromium is dissolved. Usually, depending on conditions, the passive layer is more chromium-rich, especially the inner layer. This is relevant, for example, for acidizing jobs in oil and gas industry, proving that repassivation after acidizing will happen promptly, when the pH is increased again. Ključne besede: stress corrosion cracking, surface finish impact, tapered tensile specimen, autoclave, accelerated testing, light water nuclear reactor, critical threshold stress Objavljeno v DiRROS: 30.08.2023; Ogledov: 294; Prenosov: 151 Celotno besedilo (4,01 MB) Gradivo ima več datotek! Več... |
3. Podobe gozdnega revirjaAnton Lesnik, Gal Fidej, Jože Prah, Jože Mori, Jože Kos, Jurij Diaci, Kristina Sever, Marija Imperl, 2022, poljudni članek Ključne besede: revirni gozdar Objavljeno v DiRROS: 08.03.2022; Ogledov: 849; Prenosov: 208 Celotno besedilo (522,26 KB) |
4. Allergies and COVID-19 vaccines : an ENDA/EAACI position paperAnnick Barbaud, Lene Heise Garvey, Alessandra Arcolaci, Knut Brockow, Francesca Mori, Cristobalina Mayorga, Maja Jošt, Mitja Košnik, Mihaela Zidarn, Maria J Torres, 2022, izvirni znanstveni članek Povzetek: Anaphylaxis, which is rare, has been reported after COVID 19 vaccination, but its management is not standardized. Method. Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed. Results. No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine, are excipients. The authors propose allergy evaluation of persons with the following histories: 1- anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2- anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine, 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable. Conclusions. These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated. Ključne besede: SARS-CoV-2, COVID-19, COVID-19 vaccines, allergens, anapylaxis, drug hypersensitivity Objavljeno v DiRROS: 07.02.2022; Ogledov: 804; Prenosov: 248 Povezava na datoteko |
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