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The authors aimed to impart hydroxyapatite formation ability to ultra-high molecular weight polyethylene (UHMWPE) by deposition of apatite nuclei (ApN) by the following two methods. The first method was electrophoretic deposition (EPD). A porous UHMWPE was placed between electrodes in the ApN-dispersed ethanol and constant voltage was applied. By this treatment, the ApN were migrated from anode-side surface to the cathode one through the pores by an electric field in the pores of the UHMWPE and deposited inside the pores. The second method was direct precipitation (DP) of the ApN. A porous UHMWPE was soaked in a simulated body fluid (1.0SBF) with higher pH than the physiological one and subsequently, its temperature was raised. By this treatment, the ApN were precipitated in the pores of the UHMWPE directly in the reaction solution. For both methods, the ApN-deposited UHMWPE showed HAp formation ability not only on the top surface but also inside the pores near the surface of the porous UHMWPE in 1.0SBF although the adhesion strength of thus-formed HAp layer was higher in the case of the EPD in comparison with the DP, oxygen plasma treatment before the DP enabled to achieve a similar level of the HAp layer adhesion to the EPD., Special Section: Selected Extended Papers from the International Conference of the 19th Asian BioCeramic Symposium

This paper presents, for the first time, the results of studies of the electrochemical reaction of oxygen reduction on Sr2Fe1.5Mo0.5O6-δ and Sr-deficient Sr1.95Fe1.5Mo0.5O6-δ, as promising electrodes for solid state electrochemical devices, by the electrochemical impedance method with the subsequent interpretation of the data using the concepts outlined in the Adler et al. model. It was established that the oxygen reduction reaction for both electrodes is determined by two relaxation processes associated with oxygen diffusion, oxygen surface exchange, and Knudsen diffusion in the pores of the electrode. Strontium deficiency was found to have a positive effect on the electrochemical activity of the electrodes, enhancing the stage related to oxygen diffusion and surface exchange. Also, for the first time, for Sr2Fe1.5Mo0.5O6-δ, a quantitative correlation for the surface oxygen exchange and diffusion coefficients obtained from the impedance data and by the isotopic exchange method is demonstrated. © 2021 Elsevier B.V. The authors are grateful to A.S. Farlenkov for the SEM images and A.V. Khrustov for the calculation of the microstructure parameters. The facilities of shared access center "Composition of Compounds" of IHTE UB RAS were used.

Thin-film Solid-State Batteries (TFSSB) is one of most promising and quickly developing fields in modern electrochemical energy storage. Modeling these devices is interesting from theoretical and practical point of view. This paper represents a simulation approach for TFSSB which overcome a major drawback of available mathematical models, i.e. decline in accuracy of the models at high current rates. A one-dimensional electrochemical model, including charge transfer kinetics on the electrolyte-electrode interface, diffusion and migration in electrolyte as well as diffusion in intercalation electrode has been developed and the simulation results are compared to experimental voltage-capacity measurements. A new definition of diffusion coefficient as a function of concentration, based on the experimental measurements, is used to improve the performance of the model. The simulation results fit the available experimental data at low and high discharge currents up to 5 mAh cm −2 . The models show that the cathode diffusion constant is a prime factor limiting the rate capability for TFSSB in particular for ultrafast charging applications. A© 2019 Elsevier B.V.

In the past, the diffusion of electric vehicles (EVs) has been hindered by energy storage limits. In fact, these are the reason for the limited EV range and the consequent range anxiety of their drivers. Thanks to constant improvements in storage system technologies over the years, in terms of both energy and power density, lithium-ion batteries (LiBs) now guarantee vehicle ranges higher than 150 km for small vehicles. Another important improvement has been achieved by the hybridisation of LiBs with other storage technologies such as electric double-layer capacitors or lithium-ion capacitors. By adding an additional storage unit (ASU) to the EV battery system, the overall efficiency increases, with a consequent gain in the vehicle's expected range. In a previous paper, an optimal sizing procedure was proposed, through which it is possible to calculate the optimal ASU mass that maximises the EV range for a given vehicle, ambient conditions, and driving cycle, which was considered to be known a priori. In the present work, a real-time implementation of the control strategy on which the optimal sizing procedure was based is proposed and analysed using the results of simulation tests.

In this paper, the influence mechanisms of the solution acidity and the auxiliary electrode reaction on the oxidation peak current of epinephrine (EP) were researched on a pre-anodized carbon paste electrode in a “U” shape electrolytic cell. By changing the solution acidity in the auxiliary electrode electrolytic cell (AEEC) or the working electrode electrolytic cell (WREEC), the electrochemical behaviors of EP in the WREEC was investigated by cyclic voltammetry. It is found that the magnitude of the oxidation peak current of EP is closely related to the solution acidity for both WREEC and AEEC. The effects of the supporting electrolyte, the reduction reaction at the auxiliary electrode, distribution of the EP species and the molecular configuration of EP on the oxidation peak current of EP were also explored. Furthermore, the reaction mechanisms for both cathode and anode were proposed and interpreted. With the provided electrode reaction mechanisms, optimized pH value can be chosen based on the distribution coefficients for future related researches. Satisfactory results have been achieved for the determination of EP in injection using these mechanisms.

The paper presents the results of an investigation into thin single- and triple-layer ZrO2-Sc2O3-based electrolytes prepared using the tape-casting technique in combination with promising electrodes based on La2NiO4+&delta, and Ni-Ce0.8Sm0.2O2-&delta, materials. It is shown that pressing and joint sintering of single electrolyte layers allows multilayer structures to be obtained that are free of defects at the layer interface. Electrical conductivity measurements of a triple-layer electrolyte carried out in longitudinal and transverse directions with both direct and alternating current showed resistance of the interface between the layers on the total resistance of the electrolyte to be minimal. Long-term tests have shown that the greatest degradation in resistance over time occurs in the case of an electrolyte with a tetragonal structure. Symmetrical electrochemical cells with electrodes fabricated using a screen-printing method were examined by means of electrochemical impedance spectroscopy. The polarization resistance of the electrodes was 0.45 and 0.16 Ohm∙cm2 at 800 &deg, C for the fuel and oxygen electrodes, respectively. The distribution of relaxation times method was applied for impedance data analysis. During tests of a single solid oxide fuel cell comprising a supporting triple-layer electrolyte having a thickness of 300 microns, a power density of about 160 mW/cm2 at 850 &deg, C was obtained using wet hydrogen as fuel and air as an oxidizing gas.

This paper describes a low cost portable point of test data acquisition system, made of commercial components, that was developed to interface to electrochemical sensors. The proposed system has demonstrated that it can support cyclic voltammetry, square wave voltammetry and collector generator voltammetry, with dual electrode control. The system has demonstrated its capability to detect a range of ferrocene monocarboxylic acid concentrations using nanowire electrochemical sensors, while benchmarking the results against dedicated laboratory based equipment. This work has identified and highlighted the unique challenges of interfacing to electrochemical sensors.

Caffeine is a natural alkaloid exerting many physiological effects, such as stimulation of the central nervous system, diuresis and gastric acid secretion. It is widely distributed in plant products and beverages and its quantification is mainly of pharmaceutical and alimentary concern. In this paper, we describe an electrochemical study based on the modification of a gold electrode (Au) surface by deposition of functionalized gold nanoparticles by Cyclic Voltammetry (CV). The oxidation system is characterized by an anodic peak in the positive-going step and by the absence of any cathodic peak on the reverse scan, indicating that the oxidation is irreversible. At the modified electrode, the voltammetric peak height increases vs. that @ the bare one, depending on the nanoparticles functionalization. The best performances were observed @ Au electrode modified with colloidal gold nanoparticles (AuNPs) stabilized into a chitosan matrix. In order to optimize the influence of different electrolytes on the sensor response, different electrolytic solutions (nitric acid, sulfuric acid, phosphoric acid and hydrochloric acid) were used. The electro-chemical behavior of caffeine was also studied in aprotic medium with the aim to clear up the different mechanisms the oxidative process occurs through in aqueous and in aprotic medium.