Search results for "vanA"
showing 5 items of 345 documents
Polymorphism of rare-earth orthovanadates under high pressure
2022
Los ortovanadatos de tierras raras constituyen una familia paradigmática de óxidos ternarios, debido a sus llamativas propiedades y sus diferentes polimorfos. Una gran cantidad de sus diferentes fases pueden obtenerse sometiendo a estas estructuras cristalinas a condiciones de presión y temperatura extremas. En esta tesis se estudia el comportamiento de diferentes ortovanadatos (NdVO4, GdVO4, PrVO4 y TbVO4) bajo altas presiones y diferentes condiciones de temperatura. Varias muestras de estos compuestos han sido caracterizadas a través de diversas técnicas experimentales, entre las cuales se incluyen la difracción de rayos X (DRX), la dispersión Raman y la absorción óptica. Además de esto, …
Silica powder obtained by sol-gel method as a support of organometallic vanadium catalyst for ethylene polymerization
2004
Sol-gel technique was employed to obtain the silica-type powder, which after modification procedure was applied as asupport of organometallic catalytic system for ethylene polymerization. The powder product was synthesized using hydrolysis and condensation of TEOS, catalyzed by ammonia. Obtained material and a reference support (commercial silica Davisil) were characterized to determine their particle size distributions, BET surface area, pore volume and diameter. Gas-phase adsorption of vanadium catalyst on analyzed support materials as well as adsorption from the solution in hexane were carried out. Both carrier materials were thermally pretreated prior catalytic systems syntheses and the…
An Atypical Case of Taravana Syndrome in a Breath-Hold Underwater Fishing Champion: A Case Report
2013
Dysbaric accidents are usually referred to compressed air-supplied diving. Nonetheless, some cases of decompression illness are known to have occurred among breath-hold (BH) divers also, and they are reported in the medical literature. A male BH diver (57 years old), underwater fishing champion, presented neurological disorders as dizziness, sensory numbness, blurred vision, and left frontoparietal pain after many dives to a 30–35 meters sea water depth with short surface intervals. Symptoms spontaneously regressed and the patient came back home. The following morning, pain and neurological impairment occurred again and the diver went by himself to the hospital where he had a generalized to…
Enterococcus ģints baktēriju identifikācija un vankomicīna rezistences gēnu noteikšana
2018
Pēdējo gadu laikā pasaulē strauji pieaug enterokoku rezistence pret dažādu grupu antimikrobajiem līdzekļiem un to izraisītas infekciju slimības, īpaši, nozokomiālas. Pētījuma mērķis bija noteikt no klīniskā materiāla izolēto enterokoku antibakteriālo jutību, kā arī noteikt vankomicīna rezistences gēnus. Enterococcus sp. celmu antimikrobiālā jutība tika noteikta izmantojot Kirby-Bauer disku difūzijas metodi, savukārt vankomicīna rezistences gēni enterokokos tika identificēti izmantojot Genotype Enterococcus testu. Rezumējot pētījuma datus visvairāk tika identificētas divas enterokoku sugas – E.faecalis (81 %) un E.faecium (19 %). E. faecium bija rezistentāks pret pētījumā izmantotajiem antim…
Optical limiters relying on VO2 phase transition in thin multilayer films
2022
We propose a self-activating optical limiter device based on phase transition of vanadium dioxide in thin multilayer films. The optimal geometry reduces the transmitted power by ~ 70% and shows a recovery time of 10 ns.