Fabrication and characterization of nanostructured Ni–IrO2 electrodes for water electrolysis

Nanostructured Ni–IrO₂ electrodes were fabricated by electrodeposition in a two-step procedure: first arrays of nickel nanowires (NWs) were electrodeposited within pores of polycarbonate (PC) membranes, then iridium oxide nanoparticles were deposited on the Ni metal after membrane dissolution, for improving the catalytic activity. The aim was to compare performance of these electrodes with traditional ones consisting of Ni film. Different methods of deposition of the IrO₂ electrocatalyst were investigated and the effect on electrodes stability and activity is discussed. Despite a low coverage of Ni NWs by the electrocatalyst, results indicate a faster kinetics of O₂ evolution in 1 M KOH solution and an improvement of performances for electrolysers having a nanostructured anode.     

Development of an accelerated aging method for Brandy

Brandy de Jerez plays a very important role in the economy of its production area. Currently, there are many wineries interested in innovating and diversifying their products, demanding a method which would allow them to age the spirits in a quick and simple way, enabling the testing of different variables in its elaboration.     

Impact of amplifier noise figure modeling in simulations of impairment-aware all-optical networks

In this article, we analyze and quantify the impact of the use of different amplifier noise figure models in impairment-aware optical network simulations. We compare network simulations that use three different models, two of them already known and largely employed in the literature, and a third one that we propose here, which is more appropriate to use for gain-clamped amplifiers. We present simulation results for the network blocking probability for each model, for different amplifier output saturation powers. And we also present simulation results for the distribution of optical powers at the input of each amplifier in the network. From our results we can conclude in which cases one can use a simpler model and in which other cases it is worth using a more elaborate model. We show that if the simplest and most common model is used for any network simulation, the obtained blocking probability is overestimated.     

Evolution of grape seed flavan‐3‐ols during ripening of different grape cultivars

Evolution of both catechin and epicatechin grape seed content was established for ten white and six red grape varieties during the ripening period. Chemometric techniques (cluster analysis and partial least squares analysis) were used for data analysis. An initial increasing stage and a final stabilisation step for both compounds have been observed for most varieties during ripening, including both red and white grape varieties. On the other hand, three red varieties (Tintilla de Rota, Tempranillo and Graciano) and two white varieties (Vijiriega and Muscat á Petit Grain) kept away from the rest showed particular trends. Graciano was the only cultivar that presented differences in catechin and epicatechin behaviour during its ripening period.     

Floating modular drug delivery systems with buoyancy independent of release mechanisms to sustain amoxicillin and clarithromycin intra-gastric concentrations

Release modules of amoxicillin and clarithromycin combined in a single dosage form designed to float in the gastric content and to sustain the intra-gastric concentrations of these two antibiotics used for the eradication of Helicobacter pylori have been studied. The modules having a disc shape with curved bases were formulated as hydrophilic matrices. Two modules of clarithromycin were assembled by sticking the concave base of one module to the concave base of the other, creating an internal void chamber. The final dosage form was a floating assembly of three modules of clarithromycin and two of amoxicillin in which the drug release mechanism did not interfere with the floatation mechanism. The assembled system showed immediate in vitro floatation at pH 1.2, lasting 5?h. The in vitro antibiotics release profiles from individual modules and assembled systems exhibited linear release rate during buoyancy for at least 8?h. The predicted antibiotic concentrations in the stomach maintained for long time levels significantly higher than the respective minimum inhibitory concentrations (MIC). In addition, an in vivo absorption study performed on beagle dogs confirmed the slow release of clarithromycin and amoxicillin from the assembled system during the assembly’s permanence in the stomach for at least 4?h.     

Defining amplifier’s gain to maximize the transmission rate in optical systems using evolutionary algorithms and swarm intelligence

Optical networks are currently the only technology capable of providing extremely high data transmission rates. Because of this, systems must be increasingly efficient and immune to failures. One way to improve network efficiency is to use dynamic approaches like Adaptive Control of Operating Point, which consists of autonomously choosing the best operating point for optical amplifiers on the link, thus providing the best configuration concerning Quality of transmission. Unlike the previous works that focused on optimizing Optical Signal-To-Noise Ratio, our proposal and analysis are focused on maximizing the transmission rate. In this paper, we compare the results obtained by five different and widely used evolutionary and swarm-based algorithms in the search for maximizing the transmission rate in optical links. We have observed that the differential evolution provided the best results in the analyzed scenarios.

     

Spatial dependence in the technical efficiency of local banks

Cooperative banks primarily compete with one another because they target niche markets that large banks typically ignore. The current study shows that in this competitive environment, the connection between financial intermediaries affects the operational efficiency of small banks. The findings indicate that the capitalization, diversification strategies, funding costs, liquidity, credit quality, and risk of bank neighbors have spillover effects on technical efficiency. Thus, bank networks trigger a cascading effect that demands the attention of bank stakeholders.     

OSNR model to consider physical layer impairments in transparent optical networks

We propose a model that considers several physical impairments in all-optical networks based on optical signal-to-noise degradation. Our model considers the gain saturation effect and amplified spontaneous emission depletion in optical amplifiers, coherent crosstalk in optical switches, and four-wave mixing in transmission fibers. We apply our model to investigate the impact of different physical impairments on the performance of all-optical networks. The simulation results show the impact of each impairment on network performance in terms of blocking probability as a function of device parameters. We also apply the model as a metric for impairment-constraint routing in all-optical networks. We show that our proposed routing and wavelength assignment algorithm outperforms two common approaches.