Separation of Hydrogen from Water Molecules by Ion Implantation into Thin Ti Films

The potential of hydrogen as primary gas source has generated considerable interest in hydrogen separation technologies. In the present work, the method of ion implantation has been used to separate hydrogen from energetic water molecules penetrating into Ti films. According to the results of the present study, the technique and method of implantation are capable of splitting water molecular ions into their constituent atoms with accommodation of oxygen and hydrogen atoms in interstitials of Ti film. The experimental distribution profiles are fitted with the simulated results based on the analysis of solutions of rate equations including processes of molecular ion implantation and diffusion. The dominant mechanisms transporting incident particles from the surface into the bulk are discussed. The obtained results are compared to literature data on the widely studied titanium–hydrogen bulk system. The experimental and simulation results are in consistency that molecular ions upon entering the substrate break up into constituent atoms and separation of hydrogen occurs. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3541

Oxygen implantation and behaviour into Ті thin films from water vapour plasma

The behavior of O atoms in Ti film is investigated under high-flux, low-energy molecular water ion implantation. After 10 min of irradiation at room temperature, the anomalously deep penetration of oxygen without formation of new chemical compounds observable by XRD has been registered in Ti films using Auger spectroscopy analysis. It is shown that the surface energy increases under ion irradiation, and the relaxation processes minimizing the surface energy initiate the redistribution of atoms. Two surface energy relaxation processes are considered: (i) the mixing of atoms on the surface resulting in annihilation of surface vacancies; and (ii) the annihilation of surface vacancies by atoms transported from the bulk. The theoretical considerations are in agreement with the experimental results if to assume that the mass-transport in the bulk is controlled by the processes on the surface and the adsorption of reactive atoms or molecules leads to local and long-range restructuring and adatom relocation at the surface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2081

Water Vapor-Plasma-Enhanced Oxidation of Thin Titanium Films

It is shown that the water vapor plasma processing offers modified Ti oxidation thermodynamics and kinetics over conventional, thermal oxidation. The 0.3-0.6 μm thick Ti films were sputter-deposited on silicon substrates and subsequently treated with low-pressure water vapor plasma at room temperature under continuous injection of water cloud vapor into the vacuum chamber from the heated water container. The changes of microstructure, phase composition, elemental composition and surface morphology upon the RF-power dissipated in plasma and treatment duration were investigated. We conclude that oxygen diffusion is enhanced in the presence of water vapor plasma, and deduce that fast $H^+$ transients because of their high mobility may be responsible for oxygen diffusion enhancement. This phenomenon can be explained as the result of two coexisting and competing reactions of oxidation and reduction on the surface. The different plasma reduction/oxidation state on the surface can be maintained by coordinated adjustment of an intensity of plasma radiation. Analysis of the experimental results is used to obtain important insights into the behavior of water molecules adsorbed on the oxidized titanium surfaces exposed to water vapor plasma at room temperature

Structural and Phase Transformations in Water-Vapour-Plasma-Treated Hydrophilic TiO 2

We have investigated structural and phase transformations in water-vapor-plasma-treated 200–300 nm thick Ti films, maintained at room temperature, by injecting water vapor into radio frequency (RF) plasma at different processing powers. Scanning electron microscopy (SEM) combined with optical microscopy and surface nanotopography analysis were used to view tracks of adsorbed water layers and to detect bulges or blisters appeared on the surface of treated samples. Rough surfaces with different size of holes (5–20 μm) through the entire film thickness have been observed. X-ray diffraction results show that the oxidation rate of Ti film drastically increases in the presence of an adsorbed water on the hydrophilic layer. It is assumed that the defining factor which controls oxidation kinetics is the hydroxyl radicals formation

Agonist-antagonist myoneural interface amputation preserves proprioceptive sensorimotor neurophysiology in lower limbs

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works The brain undergoes marked changes in function and functional connectivity after limb amputation. The agonist-antagonist myoneural interface (AMI) amputation is a procedure that restores physiological agonist-antagonist muscle relationships responsible for proprioceptive sensory feedback to enable greater motor control. We compared results from the functional neuroimaging of individuals (n = 29) with AMI amputation, traditional amputation, and no amputation. Individuals with traditional amputation demonstrated a significant decrease in proprioceptive activity, measured by activation of Brodmann area 3a, whereas functional activation in individuals with AMIs was not significantly different from controls with no amputation (P< 0.05). The degree of proprioceptive activity in the brain strongly correlated with fascicle activity in the peripheral muscles and performance on motor tasks (P < 0.05), supporting the mechanistic basis of the AMI procedure. These results suggest that surgical techniques designed to restore proprioceptive peripheral neuromuscular constructs result in desirable central sensorimotor plasticity