Mar Drugs
December 2024
Five new non-holostane di- and trisulfated triterpene pentaosides, conicospermiumosides A-1 (), A-2 (), A-3 (), A-1 (), and A-2 () were isolated from the Far Eastern sea cucumber Levin et Stepanov (Cucumariidae, Dendrochirotida). Twelve known glycosides found earlier in other species were also obtained and identified. The structures of new compounds were established on the basis of extensive analysis of the 1D and 2D NMR spectra, as well as by the HR-ESI-MS data.
View Article and Find Full Text PDFThree new bibenzochromenones named phanogracilins A-C (-) were isolated from the crinoid . The structure of was established using X-ray crystallography as 5,5',6,6',8,8'-hexahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4'-dione. This allowed us to assign reliably 2D NMR signals for compound and subsequently for its isomer that differed in the connecting position of two benzochromenone moieties (7,10' instead of 7,9'), and compound for that differed in the length of the aliphatic chain of one of the fragments.
View Article and Find Full Text PDFMicron
March 2023
High-entropy alloys (HEAs) are promoted as promising materials for various applications, including those dealing with high-temperatures. It requires understanding of the oxidation at different temperatures, especially for such a technological process as additive manufacturing (AM), which is able to produce unique structure. The present work evaluates the oxidation resistance of the CrFeCoNiAl HEAs produced by AM of the blends of CrFeCoNi and Al powders at temperatures of 800 and 1000 ℃.
View Article and Find Full Text PDFJ Therm Spray Technol
January 2022
The abradable coatings had significantly enhanced turbomachinery performance by acting as a sacrificial seal between rotating blades and stationary casing. Further improvement in seal design to meet the higher energy demand and increase the service time has been the key challenge to solve in the gas turbine industry. Honeycomb seals have become the industry standard clearance seal technique due to their unique design and high structural strength with minimum weight.
View Article and Find Full Text PDF