The obtained Q0 value of a superconducting niobium cavity is known to depend on various factors like the RRR of the Niobium material, crystallinity, chemical treatment history, the high-pressure rinsing process, or effectiveness of the magnetic shielding. We have observed that spatial thermal gradients over the cavity length during cool-down appear to contribute to a degradation of Q0. Measurem...

The molecular structures and reactivity of surface modified niobium oxide catalysts were determined by Raman spectroscopy, pyridine adsorption as well as the methanol oxidation reaction. Metal oxides (RexO,, CrOx, WOs, Moos, and V206) and acids (phosphate and sulfate) form a surface overlayer on the niobia support, and possess a structure similar to the metal oxide ionic species present in acid...

the purpose of this study was to compare shear bond strength (sbs) of orthodontic brackets bonded to enamel prepared by er:yag laser with two different powers and conventional acid-etching.forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: group 1- conventional etching with 37% phosphoric acid; group 2- irradiation ...

In this work, Nb5+ and In3+ ions were used as dopants in titanium/tungsten oxide nanostructures that are produced by the electrospinning sintering process, for relative humidity (RH) detection. The microstructural properties investigated SEM, EDS, XRD, Raman FTIR techniques. electrical response characterization of samples was performed impedance spectroscopy range 400 Hz to 40 MHz, at 20 °C. se...

Accelerator driven transmutation of waste is one complementary approach to deal with spentnuclear fuel as compared to permanent storage. High-energy protons generated by a particleaccelerator collide with a heavy metal target producing neutrons. Long-lived radioactive isotopesinteracting with the neutrons transmute into shorter-lived isotopes. To generate the high-energyprotons ...

Isostructural vanadium, niobium and tantalum complexes of bis(3,5-di-tert-butyl-2-phenol)amine ([ONO]H3), were prepared and characterized to evaluate the impact of the metal ion on redox-activity of the ligand platform. New vanadium and niobium complexes with the general formula, [ONO]MCl2L (M = V, L = THF, 1-V; M = Nb, L = Et2O, 1-Nb) were prepared and structurally analysed by X-ray crystallog...

The size of photochemically-prepared niobium nanoparticles (NbNP) can be controlled by varying the concentration of the photoinitiator in the reaction mixture. The particles, which may be metallic in nature, are readily oxidized upon air exposure to form stable niobium(v) oxide nanoparticles (NbONP) that act as strong Brønsted acids.

This study utilized solid-state lasers with a 50 ns pulse duration in Q-switched mode of operation at wavelengths 1.06 µm and 0.69 to investigate the hemispherical reflectivity niobium. Our experimental results show that niobium decreases notably as laser fluence increases towards plasma formation threshold for ablation both studied wavelengths, which we attribute changes absorptivity surface r...