This study evaluated the behavior of three paint systems exposed to the Antarctic marine environment for 45 months compared to a control of uncoated carbon steel with a determined corrosion rate. At the study site, all environmental conditions, solar radiation, and the concentration of environmental pollutants (Cl- and SO) were evaluated. The paint systems differed in terms of the primer and top coat. Coated samples were studied before and after exposure. They were evaluated visually and using SEM to determine adhesion, abrasion, and contact angle; using the Evans X-Cut Tape Test; using ATR-FTIR spectroscopy to analyze the state of aging of the top layer; and using electrochemical impedance spectroscopy (EIS) for coat protection characterization. The corrosion rate obtained for steel was 85.64 µm year, which aligned with a C5 environmental corrosivity category. In general, the evaluation in the period studied showed the paint systems had good adhesion and resistance to delamination, without the presence of surface rust, and exhibited some loss of brightness, an increase in the abrasion index, and a decrease in the percentage of reflectance due to aging. EIS showed good protection capability of the three coating schemes. In general, this type of paint system has not previously been evaluated in an extreme environment after 45 months of exposure to the environment. The results showed that the best behavior was found for the system whose top layer was acrylic-aliphatic polyurethane.
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http://dx.doi.org/10.3390/ma16165713 | DOI Listing |
Int J Mol Sci
December 2024
Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Mammalian blood cells originate from specialized 'hemogenic' endothelial (HE) cells in major arteries. During the endothelial-to-hematopoietic transition (EHT), nascent hematopoietic stem cells (HSCs) bud from the arterial endothelial wall and enter circulation, destined to colonize the fetal liver before ultimately migrating to the bone marrow. Mechanisms and processes that facilitate EHT and the release of nascent HSCs are incompletely understood, but may involve signaling from neighboring vascular endothelial cells, stromal support cells, circulating pre-formed hematopoietic cells, and/or systemic factors secreted by distal organs.
View Article and Find Full Text PDFNature
January 2025
Laboratory for Immune Cell Systems, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan.
Our understanding of type 2 immunity has undergone a substantial transformation in recent years, revealing previously unknown functions. Beyond its canonical role in defence against parasitic helminth infections, type 2 immunity safeguards the host through additional mechanisms, including the suppression of excessive type 1 immune responses, regulation of tissue repair and maintenance of adipose tissue homeostasis. However, unlike type 1 immune responses, type 2 immunity is perceived as a potential promoter of tumorigenesis.
View Article and Find Full Text PDFNaturwissenschaften
January 2025
Institute for Animal Cell and Systems Biology, University of Hamburg, Martin-Luther-King Platz 3, Hamburg, 20146, Germany.
Physiological or genetic assays and computational modeling are valuable tools for understanding animals' visual discrimination capabilities. Yet sometimes, the results generated by these methods appear not to jive with other aspects of an animal's appearance or natural history, and behavioral confirmatory tests are warranted. Here we examine the peculiar case of a male jumping spider that displays red, black, white, and UV color patches during courtship despite the fact that, according to microspectrophotometry and color vision modeling, they are unlikely able to discriminate red from black.
View Article and Find Full Text PDFMolecules
December 2024
Centro per la Conservazione ed il Restauro dei Beni Culturali "La Venaria Reale", Via XX Settembre 18, 10078 Venaria Reale, Turin, Italy.
The formation of metal soaps or carboxylates in oil paintings is a widely studied topic. Expanding upon the extant research on the subject, this work investigates the formation of metal soaps as pertaining to alkyd-based media. Especially popular in modern and contemporary art, alkyd paints are complex commercial formulations mainly containing a polyester backbone obtained by the condensation of glycerol and phthalic acids, where the third free alcoholic function is esterified with a blend of saturated and unsaturated fatty acids.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Mechanical Engineering and Computer Science, University of Bielsko-Biala, Willowa 2, 43-309 Bielsko-Biala, Poland.
The article compares the properties of coatings (cataphoretic, hot-dip zinc, and thermo-diffusion zinc) applied to steel components used in the automotive industry. The research focused on the analysis of corrosion resistance, hardness measurements, and tribological properties conducted on steel guides used in trailer and truck body structures as well as fasteners (M12 × 40 bolts). The base surfaces were cleaned chemically.
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