Tailoring of surface topography of carbon electrodes for supercapacitors using plasma technologies

In this work, we address the issue of controlled modification of the surface topography of carbon materials when subjected to oxygen-based plasma treatment, and we investigate the resulting enhanced surface area as a mean of controlling the capacitance of supercapacitors. It is shown that carbon layers with porous of controllable nanoscale size can be tuned from nanoporous to mesh-like employing atmospheric plasma torch deposition technology and following appropriate plasma processing. The nanoscale carbon processing is optimized to form surface topographies that promote carbon wettability with electrolyte. Three dimensional structures fabricated on carbon are chosen as appropriate surfaces for the enhancement of the capacitance of supercapacitors. This fact underlines the potential application of the proposed technique for fabricating electrolyte-wetted carbon electrodes for supercapacitors. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2086

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

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

Surface topography analysis of water vapor plasma irradiation induced effects in Ті films

In the present work, the changes of surface topography driven by interaction of ions extracted from low-pressure water vapor plasma are studied. Titanium 0.5-1 um thickness films were deposited on silicon wafer substrates using magnetron sputtering technique and immersed in water vapor plasma at pressure 1-10 Pa. The samples were located on the cathode of magnetron and affected by high-flux, low-energy ions extracted by 250-300V bias negative voltage. The used Ti and W cathodes were water cooled. It is shown that the surface roughness of irradiated films changes in dependence of irradiation fluence and intensity. The experimental results are explained on the basis of the analysis of the selective erosion of oxide phases synthesized in the near-surface region. Three sputtering modes are distinguished: (i) metallic, (ii) oxide and (iii) composite: metallic with clusters of oxide. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2084

Integrated analysis of communication protocols by means of PLA formalism, Journal of Telecommunications and Information Technology, 2004, nr 4

Aggregate approach and its possibilities for specification and analysis of computer network protocols are presented. The theoretical basis of the aggregate approach is a piece-linear aggregate (PLA) for formal specification of systems. The advantage of that approach is that it permits to create models both for analysis correctness of specifications and simulation. Some methods that can be used for validation and verification of aggregate specifications are presented also

Scenario Tree Generation By Clustering The Simulated Data Paths

Multistage stochastic programs are effective for solving long-term planning problems under uncertainty. Such programs are usually based on a scenario model of future environment developments. A good approximation of the underlying stochastic process may involve a very large number of scenarios and their probabilities. We discuss the case when enough data paths can be generated, but due to solvability of stochastic program the scenario tree has to be constructed. The proposed strategy is to generate the multistage scenario tree from the set of individual scenarios by bundling scenarios based on cluster analysis. The K-means clustering approach is modified to capture the interstage dependencies in order to model the sequential decisions. The described scenario tree generation method is implemented on sampled data of nominal interest rate

Transesophageal echocardiography-guided versus fluoroscopy-guided patent foramen ovale closure : A single center registry

Percutaneous closure of patent foramen ovale (PFO) is conventionally performed under continuous transesophageal echocardiographic (TEE) guidance. We aimed to evaluate whether a simplified procedural approach, including pure fluoroscopy-guidance and final TEE control, as well as an aimed 'next-day-discharge' is comparable with the conventional TEE-guided procedure in terms of periprocedural and intermediate-term outcomes.All patients who underwent a PFO closure at our center between 2010 and 2022 were retrospectively included. Prior to June 2019 cases were performed with continuous TEE guidance (TEE-guided group). Since June 2019, only pure fluoroscopy-guided PFO closures have been performed with TEE insertion and control just prior to device release (fluoroscopy-guided group). We analyzed procedural aspects, as well as long term clinical and echocardiographic outcomes.In total 291 patients were included in the analysis: 197 in the TEE-guided group and 94 in the fluoroscopy-guided group. Fluoroscopy-guided procedures were markedly shorter (48 ± 20 min vs. 25 ± 9 min; p < .01). There was no difference in procedural complications, including death, major bleeding, device dislodgement, stroke or clinically relevant peripheral embolization between the two groups (.5% vs. 0%; p = .99). Hospital stay was also shorter with the simplified approach (2.5 ± 1.6 vs. 3.5 ± 1.2 days; p < .01), allowing 85% same-day discharges during the last 12 months of observation period. At 6 ± 3 months echocardiographic follow-up a residual leakage was described in 8% of the TEE-guided cases and 2% of the fluoroscopy-guided cases (p = .08).While a complete TEE-free PFO closure might have potential procedural risks, our approach of pure fluoroscopy-guided with a brisk final TEE check seems to be advantageous in terms of procedural aspects with no sign of any acute or intermediate-term hazard and it could offer an equitable compromise between the two worlds: a complete TEE procedure and a procedure without any TEE

Open-source computational framework for studying Drosophila behavioral phase

This protocol describes a standardized method for analyzing Drosophila behavioral rhythmicity under light dark cycles, temperature ramps, and free running conditions. The protocol constitutes a step-by-step guide from generation of appropriate Drosophila genetic crosses to behavioral experiments. We also provide an opensource computational framework using R for the analysis of the phase of behavior using circular statistics. An extended method for complete use is also provided. For complete details on the use and execution of this protocol, please refer to Fernandez et al. (2020)

Sites of Circadian Clock Neuron Plasticity Mediate Sensory Integration and Entrainment

Networks of circadian timekeeping in the brain display marked daily changes in neuronal morphology. In Drosophila melanogaster, the striking daily structural remodeling of the dorsal medial termini of the small ventral lateral neurons has long been hypothesized to mediate endogenous circadian timekeeping. To test this model, we have specifically abrogated these sites of daily neuronal remodeling through the reprogramming of neural development and assessed the effects on circadian timekeeping and clock outputs. Remarkably, the loss of these sites has no measurable effects on endogenous circadian timekeeping or on any of the major output functions of the small ventral lateral neurons. Rather, their loss reduces sites of glutamatergic sensory neurotransmission that normally encodes naturalistic time cues from the environment. These results support an alternative model: structural plasticity in critical clock neurons is the basis for proper integration of light and temperature and gates sensory inputs into circadian clock neuron networks

Effect of hydrocephalus on rat brain extracellular compartment

<p>Abstract</p> <p>Background</p> <p>The cerebral cortex may be compressed in hydrocephalus and some experiments suggest that movement of extracellular substances through the cortex is impaired. We hypothesized that the extracellular compartment is reduced in size and that the composition of the extracellular compartment changes in rat brains with kaolin-induced hydrocephalus.</p> <p>Methods</p> <p>We studied neonatal (newborn) onset hydrocephalus for 1 or 3 weeks, juvenile (3 weeks) onset hydrocephalus for 3–4 weeks or 9 months, and young adult (10 weeks) onset hydrocephalus for 2 weeks, after kaolin injection. Freeze substitution electron microscopy was used to measure the size of the extracellular compartment. Western blotting and immunohistochemistry with quantitative image densitometry was used to study the extracellular matrix constituents, phosphacan, neurocan, NG2, decorin, biglycan, and laminin.</p> <p>Results</p> <p>The extracellular space in cortical layer 1 was reduced significantly from 16.5 to 9.6% in adult rats with 2 weeks duration hydrocephalus. Western blot and immunohistochemistry showed that neurocan increased only in the periventricular white matter following neonatal induction and 3 weeks duration hydrocephalus. The same rats showed mild decorin increases in white matter and around cortical neurons. Juvenile and adult onset hydrocephalus was associated with no significant changes.</p> <p>Conclusion</p> <p>We conclude that compositional changes in the extracellular compartment are negligible in cerebral cortex of hydrocephalic rats at various ages. Therefore, the functional change related to extracellular fluid flow should be reversible.</p