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We report on a comparative study of the performance level of H2/O2 PEM fuel cells in which the catalytic layers containing Pt nanoparticles were deposited on the microporous layer side of gas diffusion electrodes, using three different deposition techniques: (i) by magnetron sputtering, (ii) by impregnation followed by chemical reduction (using either ethylene glycol or hydrogen or sodium borohydride as reducing agent), and (iii) by spraying a catalytic ink (containing either Pt/C or bulk Pt particles). The microstructure and chemical composition of the different catalytic layers has been determined by SEM, TEM, XRD and XPS analysis. Their electrochemical surface areas have been determined by cyclic voltammetry. The i-V curves have been measured and compared. A durability stress test based on cycles of potential was used to assess the degradation rate of the different catalytic layers and to rank performance.

The article deals with the issues of risks of lessees and lessors in leasing operations, the use of which is associated with a decrease in investment in fixed assets of enterprises. Attention is paid to risk management methods in leasing operations. It is noted that there are currently no clear methodological recommendations for combating risks in leasing activities. A brief statistical overview of the leasing market is given. The authors point out that currently, in order to combat risks, all leasing transactions will be transferred to credit bureaus. The conclusion is made about the need to minimize the risks of leasing operations.

Nanostructured platinum-based electrocatalysts modified with tin dioxide (SnO2) are studied for their performance in highly efficient oxidation of an alcohol additive (methanol) to the hydrogen flow in fuel cells with proton exchange membrane designed for operation in low temperature conditions (to –50°C). The activity of electrocatalysts in the oxygen reduction reaction (ORR) and the methanol oxidation reaction is studied by the rotating disk electrode technique. The catalysts Pt20/10 wt %–SnO2/C and Pt20/C exhibit higher ORR activity (specific activity around 0.25 mA/cm2) than Pt40/C in a 0.1 M HClO4 solution. The activity of catalyst Pt20/10 wt %–SnO2/C nearly doubles in a solution containing methanol at 4 wt %, suggesting its high activity in methanol oxidation reaction. For the platinum in Pt20/10 wt %–SnO2/C, the electrochemical active surface area is 58 m2/g, which exceeds this parameter for Pt40/C (43 m2/g). Nanoscale Pt–SnO2 heteroclusters in the electrocatalyst Pt20/10 wt %–SnO2/C ensure its high activity in the electrooxidation reactions of both methanol and hydrogen, and they are also effective as a catalyst for the anode. Their high ORR activity, along with improved durability, compared to Pt40/C and Pt20/C catalysts, ensures their efficiency as cathode catalysts in fuel cell.

In this paper, we study the effect of platinum loading on the structure, density, and uniformity of deposition of a platinum film sputtered by a magnetron, as well as on the electrochemical characteristics of the deposited electrodes, such as the electrochemically active surface area of platinum (EASA), the durability of the electrodes, and the electrochemical performance of membrane-electrode assemblies of a fuel cell generally. An increase in the mean diameter of individual platinum particles from 1.5 to 3.8 nm and particle agglomerates from 5 to 12 nm, respectively, is shown to be observed as the platinum loading in the samples increases from 0.15 to 1.65 mg/cm2. A decrease in the EASA of catalysts occurs due to an increase in the thickness of the sputtered film and partial overlap of the active sites of the electrocatalyst. In this case, the platinum film is a nanostructured catalytic layer with a high degree of uniformity of the deposited metal. The catalytic layers obtained by sputtering platinum using a magnetron in a pulsed mode are characterized by high values ​​of the active surface up to 112 m2/g and improved durability due to the strong interaction of active sites and carbon particles of the substrate, which is confirmed by the results of X-ray diffraction analysis. EASA losses of platinum in the process of stress testing for deposited electrodes were about 20%, which is twice lower than that for catalytic layers based on platinum powder electrocatalysts. The current–voltage characteristics of a fuel cell with deposited electrodes as a cathode increase with increasing the platinum film thickness. The maximal characteristics were obtained for electrodes with a platinum film thickness of about 100 and 200 nm; values ​​of 0.43 and 0.52 A/cm2 were obtained at 0.5 V.

A study on the optimization of the method of application of the Ni catalyst for the growth of carbon nanotubes (CNTs) onto the gas diffusion layers (GDLs) (predominantly carbon cloths) by magnetron sputtering is presented. The mode of magnetron sputtering of the Ni catalyst which makes it possible to obtain a uniform metal coating on the GDLs which is required for the successful synthesis of CNTs is selected for the first time. It is shown that the sputtering of Ni in the direct current mode with the supply of pulsed bias voltage to the substrate with a frequency of 100 kHz and time of supply of the negative pulse of 7 µs makes it possible to obtain the optimum nanostructured coating of the metal with a low specific surface and a high degree of uniformity of application onto the entire area of the substrate. The applied Ni coating acts as the catalyst for the growth of CNTs. CNT arrays with the average diameters of 40 and 80 nm for the hydrophobic and hydrophilic GDLs, respectively, are grown on the GDLs with the applied Ni catalyst by pyrolytic gas-phase deposition. The CNT arrays are directly obtained on the entire surface of the carbon substrates with a high degree of uniformity. It is found that the diameter of the nanotubes is mainly determined by the structure of the GDL being used.

The research was aimed at studying the influence of distance learning format on the educational activity motivation of full-time students, as well as at conducting a comparative analysis of the 1st and 2nd year full-time students' educational activity motivation in the context of traditional and distant learning formats. The article presents the results of the study conducted in Cherepovets State University.Theoretical background is primarily based on the studies of activity motivation phenomenology. To collect empirical data, a standardized diagnostic technique “Scales of internal and external motivational orientation” by Amabil (adaptation of Gordeeva and Osin) and survey methods were used. The results analysis showed that in distance learning conditions, the number of students with internal motivation decreased from 32% in 2019 to 28% in 2020, while the number of students with external negative motivation increased significantly from 29% in 2019 to 42% in 2020. To understand the reasons for the changes in educational activity motivation, the survey of students and teachers was carried out.The comparative analysis of educational activity motivation of full-time students in traditional and distance learning formats, the analysis of external and internal reasons for negative tendencies manifestation in changing educational motivation allowed us to identify and to test the tools for supporting the students’ internal motivation and minimizing negative trends arising in the process of forming educational motivation in the context of distance learning.

This article presents development of magnetron sputtering technology for catalytic Pt coating production. Low Pt-loaded gas diffusion electrodes were prepared by a single-step magnetron sputtering in different regimes. Pt and Pt-carbon films (95–97 wt% Pt) were deposited directly onto the gas diffusion layers (GDLs): carbon paper (Sigracet® 39 BC) and carbon cloths (GDL-CT, ELAT® LT 1400 W). A bipolar pulsed direct current (DC) magnetron sputtering with pulsed frequency 100 kHz was used as the method for catalysts deposition. Total Pt loading in the thin films varied in the range 0.04–0.13 mg*cm−2. Obtained catalysts onto GDLs were investigated by scanning/transmission electron microscope (S/TEM), X-ray Absorption Near Edge Structure (XANES) and potentiodynamic methods. The deposited catalysts had a high electrochemical surface area (ECSA) and stability determined by the durability stress test (DST) method. The highest ECSA was obtained with Pt target in the pulsed (100 kHz) sputtering mode. This ECSA values were rather stable during 3000 cycles of stress-tests versus 500 cycles for Pt deposited by polyol method on the same gas diffusion layers.

For each n > 2 we classify all n-dimensional algebras over an arbitrary infinite field which have the property that the n-dimensional abelian Lie algebra is their only proper degeneration.

Two chromophores with π-deficient quinoxaline (Q) core in the π-electron bridge together with dibutylaniline (DBA) donor moiety and tricyanofuranyl (TCF) or dicyanovinyl (DCV) acceptor moieties have been synthesized to investigate their macroscopic nonlinear optical (NLO) activity in guest-host materials. A distinctive feature of the 7-DBA-VQPhV-TCF chromophore is predominance of negative solvatochromism over the positive one, which is quite rarely met for the chromophores manifesting inverse solvatochromic behavior as well as the blue shift of the absorption maximum compared to the chromophore FTC with divinylthiophene π-bridge. Introduction of quinoxaline moiety in the conjugated bridge promotes the increase of thermal stability: Td of both compounds is higher than 225 °C. Density functional theory was used to calculate the chromophores first hyperpolarizability (β). Quadratic NLO response characterized by d33 coefficient was measured by SHG technique for thin guest-host polymer films. The influence of chromophore content on the NLO coefficient of 7-DBA-VQPhV-TCF/PMMA film has been investigated and the d33 value of this film reaches 108 pm/V at 25 wt% load. The poled film 7-DBA-VQPh-DCV/PMMA shows twice smaller d33 values (30 pm/V) at the same chromophore load (20 wt%).

Changing priorities in teacher training have necessitated a new model for prospective specialists training, taking into account the rapidly changing educational environment. In this regard, project module for prospective teachers' training is considered to be one of the most important structural components of the baccalaureate curriculum.The study is aimed at the development of project training design as a technological component of future teachers' practice-oriented training. The main research method was the modeling method, which allowed, on the basis of abstraction, to determine the integration links between project activities and other components of the university educational.The article provides an overview of the studies on project training genesis, summarizes the organizational and technological solutions used by universities in organizing project-based training.In course of the study, conceptual provisions on the integration of project training with different types of educational activities on the basis of activity and reflective approaches, were determined. The authors substantiated and graphically presented the continuity of the project activity cycles of a certain type of project, developed the trajectories for integrating project into different types of educational activities, and also proposed a design for embedding a project module in the bachelors' training educational process.The results of the study can be used in designing baccalaureate educational programs on the specialties "Education and Pedagogical Sciences", and can also be applied to other areas and profiles of the future specialists' training in higher education.

The storage and the operation of proton exchange membrane fuel cells (PEM FCs) at subzero temperatures result in the ageing and degradation of membrane-electrode assemblies (MEAs). In this study, we investigated the effect of a freeze-thaw temperature cycles (from ambient down to −80 °C) on various properties of PFSA membranes and on the performance level of MEAs. The beneficial effects resulting from the addition of methanol vapor to the hydrogen have been put into evidence. Small angle x-ray scattering (SAXS) data have been measured on membranes swollen with water and water-methanol mixtures, to identify possible microstructure differences. It was found that the addition of methanol tends to increase the ionic resistivity of the membranes but has a protective effect on the catalytic layers during the freeze-thaw cycles. The degradation rate of the catalytic layer was reduced by almost a factor of two as a result of optimal methanol addition.

Two novel chromophores with dibutylaniline donor moiety, 3,7-(di)vinylquinoxalinone π-electron bridge and tricyanofuranyl or dicyanovinyl acceptor moieties are synthesized and their properties were systematically investigated. Atomistic modeling of PMMA-based composites with the developed chromophores as guests is performed and nonlinear optical activity is studied for the first time. Atomistic modeling performed in the amorphous cell has shown that chromophore content 20 wt% may be considered most favorable for achievement of optimal d33 values for 7-DBA-VQonV-TCF/PMMA material. Various non-covalent interactions both between chromophores and polymer matrix and chromophores inter se were revealed in the course of modeling; these interactions could contribute to the relaxation stability of orientational order and thus quadratic NLO response. Composite material 7-DBA-VQonV-TCF/PMMA is characterized by nonlinear-optical coefficient, d33, values of 97, 111 and 47 pm/V at chromophore content of 10, 20 and 30 wt%, respectively. Thus chromophore content 20 wt% provides maximal value of NLO coefficient, what is in agreement with the obtained theoretical data. The d33 value for 7-DBA-VQonV-DCV/PMMA is 2.5 times smaller than that for 7-DBA-VQonV-TCF/PMMA at the same chromophore load (20 wt%).

For the first time the nonlinear optical (NLO) activity of indolizine-based push-pull chromophores with different acceptor moieties was studied and compared. All the chromophores demonstrate strong absorption band in the visible (orange-red) part of the spectrum, with e of ca. 105 L∙cm−1∙M−1 notably dependent on medium polarity. Replacement of Ph-TCF acceptor by Hex-TCP one results in twofold increase of the first hyperpolarizability value. Energy gaps estimated by electrochemical methods decrease in the series ΔE1a,b>ΔE3a,b>ΔE2a,b for compounds with Ph-TCF, DCM and Hex-TCP acceptors, respectively, good agreement with DFT estimations is obtained. The nonlinear optical coefficient for poled PMMA-based films, containing 20 wt% of isomeric indolizine chromophores with weaker dicyanomethylene (DCM) acceptor and with π- bridge expanded by isophorone moiety, achieves 36 pm/V, thus exceeding those for materials containing chromophores with stronger Ph-TCF or Hex-TCP acceptors and with short vinylene π-bridge.

For the first time bichromophore nonlinear optically active compounds, 3,5-bis [2- (N-ethyl-4- (4′-nitrophenylazo) anilino) ethoxy] benzyl alcohol, DF1, and 3,5-bis [6- (N-methyl-4- (4′-nitrophenylazo) anilino) hexaoxy] benzyl alcohol, DF2, have been synthesized. The synthesis of the epoxy-amine oligomers containing DF1 and DF2 dendritic fragments in the side chain was preceded by molecular design which demonstrated that the hexyl groups, binding the chromophores to the branching center in DF2, are able to provide greater mobility of the chromophores compared to the ethyl groups in DF1, thus determining the preference of the former from the viewpoint of NLO activity. Bi-chromophore compounds were introduced into the side chain of epoxy amine oligomers using the esterification reaction under mild conditions by the Steglich method. As a result, oligomers OAB-DF1 (Tg = 122 °C) and OAB-DF2 (Tg = 107 °C) were obtained with good yields, the degree of functionalization was 60 mol% and 45 mol%, respectively. The values of the NLO coefficients, d33, were measured by second harmonic generation technique; they are equal to 29 pm/V for OAB-DF1 and 40 pm/V for OAB-DF2.

To further explore the potential application of the indolizine donor group in nonlinear optical (NLO) chromophores, we have designed and synthesized new push-pull chromophores (MPI-1)-V-TCF and (MPI-3)-V-TCF, having isomeric 3(1)-methyl-2-phenylindolizin-1(3)-yl (MPI-1(3)) electron donor and TCF acceptor, and compared them with dimethyl aniline (DMA) analogues. The Uv-Vis (linear optical) properties and solvatochromic behavior were also investigated; theoretical predictions of molecular NLO characteristics were done on the basis of the DFT calculations. The indolizine-based chromophores have high thermal stability: the decomposition temperature is 348 °C for (MPI-1)-V-TCF and 343 °C for the (MPI-3)-V-TCF, which is by 10–15 °C higher than that for the chromophore DMA-V-TCF. An important role is played by the bulky phenyl group, which prevents the aggregation of chromophores in guest-host doped polymer films. In NLO activities, the doped (MPI-1)-V-TCF/PMMA and (MPI-3)-V-TCF/PMMA films display the NLO coefficient, d33, values of 40 and 42 pm/V, correspondingly, at the chromophore load of 20 wt%.

New polymer materials based on methacrylic copolymers with chromophore-containing dendritic fragments in the side chain have been obtained. The nonlinear optical coefficients of 22, 23 and 28 pm V–1 have been determined for polymers with 18, 21 and 30 mol% content of dendritic fragments, respectively.

At present, the issue ecological balance restoring and rational resource con-sumption is especially acute, which determines large-scale transformations at the world level, as well as the need to modernize the tools for socio-economic develop-ment systems of countries (macro-level), individual territories and regions (meso-level), a set of interacting economic systems and economic units (microlevels). The article examines the problems of responsible resource consumption in regional socioeconomic systems, which led to change of effective growth paradigm to: 1) the sustainable development paradigm, society’s informatization; 2) selective regional policy of interregional differentiation. Obviously, at the macro-level, there is an intensive search for effective management of regional resource consumption; development of mechanisms and tools for environmental responsibility management. That is why a decrease in the level of negative impacts, as well as the consequences of low socio-economic development, determines the genesis of responsible resource consumption tools in regions’ strategizing as a key development task. However, the study of the ontology “responsible resource consumption tools” goes through the concept of sustainable development and is transformed into an integral, logically linked system of views, united by a common idea and aimed at achieving the goal of work.

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current&ndash, voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

Potassium-selective solid-contact electrodes (ISEs) with various transducer layers are studied by means of the zero-current potentiometry, electrochemical impedance spectroscopy, chronopotentiometry, and SEM. The study is focused on the stability of the ISE potentials over time. A relatively good stability is shown by ISEs with (i) C 60 and C 70 fullerene-enriched carbon black (SD = 5.7 mV over 80 days) and with (ii) the combination of ordinary carbon black, poly(amidoacid) Cu(I) complex, and electron-ion exchanging resin in the transducer layer (SD = 3.3 mV over 80 days). Passing a current through the ISEs results in polarization which can be decomposed into a decaying exponent (slow redox reaction) and a diffusional polarization at the interface between the membrane and the transducer layer. There is no correlation between the exponential component of the polarization and the long-term stability of the ISE potentials, whereas the latter correlates with the diffusional part of the polarization. In turn, the diffusional polarization is low when the transducer layer contains the primary ion (K + ), and/or the electronic conductor in the transducer layer has a higher specific surface area and/or smaller pores.

We perform the complete Lie group classification of a ( 2 + 1 ) - and a ( 3 + 1 ) -dimensional classes of non-linear diffusion–convection equations. This classification generalizes and completes existing results in the literature. The derived Lie symmetries are used for construction of similarity reductions and exact solutions of certain equations from both classes.

We carry out an extensive investigation of conservation laws and potential symmetries for the class of linear (1+1)-dimensional second-order parabolic equations. The group classification of this class is revised by employing admissible transformations, the notion of normalized classes of differential equations and the adjoint variational principle. All possible potential conservation laws are described completely. They are in fact exhausted by local conservation laws. For any equation from the above class the characteristic space of local conservation laws is isomorphic to the solution set of the adjoint equation. Effective criteria for the existence of potential symmetries are proposed. Their proofs involve a rather intricate interplay between different representations of potential systems, the notion of a potential equation associated with a tuple of characteristics, prolongation of the equivalence group to the whole potential frame and application of multiple dual Darboux transformations. Based on the tools developed, a preliminary analysis of generalized potential symmetries is carried out and then applied to substantiate our construction of potential systems. The simplest potential symmetries of the linear heat equation, which are associated with single conservation laws, are classified with respect to its point symmetry group. Equations possessing infinite series of potential symmetry algebras are studied in detail., Comment: 67 pages, minor corrections

Classifications of symmetries and conservation laws are presented for a variety of physically and analytically interesting wave equations with power onlinearities in n spatial dimensions: a radial hyperbolic equation, a radial Schrodinger equation and its derivative variant, and two proposed radial generalizations of modified Korteweg--de Vries equations, as well as Hamiltonian variants. The mains results classify all admitted local point symmetries and all admitted local conserved densities depending on up to first order spatial derivatives, including any that exist only for special powers or dimensions. All such cases for which these wave equations admit, in particular, dilational energies or conformal energies and inversion symmetries are determined. In addition, potential systems arising from the classified conservation laws are used to determine nonlocal symmetries and nonlocal conserved quantities admitted by these equations. As illustrative applications, a discussion is given of energy norms, conserved H^s norms, critical powers for blow-up solutions, and one-dimensional optimal symmetry groups for invariant solutions., Comment: 16 pages. Final version with minor revisions

We study conservation laws and potential symmetries of (systems of) differential equations applying equivalence relations generated by point transformations between the equations. A Fokker-Planck equation and the Burgers equation are considered as examples. Using reducibility of them to the one-dimensional linear heat equation, we construct complete hierarchies of local and potential conservation laws for them and describe, in some sense, all their potential symmetries. Known results on the subject are interpreted in the proposed framework. This paper is an extended comment on the paper of J.-q. Mei and H.-q. Zhang [Internat. J. Theoret. Phys., 2006, in press]., 10 pages

The fast diffusion equation $u_t=(u^{-1}u_x)_x$ is investigated from the symmetry point of view in development of the paper by Gandarias [Phys. Lett. A 286 (2001) 153-160]. After studying equivalence of nonclassical symmetries with respect to a transformation group, we completely classify the nonclassical symmetries of the corresponding potential equation. As a result, new wide classes of potential nonclassical symmetries of the fast diffusion equation are obtained. The set of known exact non-Lie solutions are supplemented with the similar ones. It is shown that all known non-Lie solutions of the fast diffusion equation are exhausted by ones which can be constructed in a regular way with the above potential nonclassical symmetries. Connection between classes of nonclassical and potential nonclassical symmetries of the fast diffusion equation is found., 13 pages, section 3 is essentially revised

All possible linearly independent local conservation laws for n-dimensional diffusion–convection equations u t=(A(u)) ii +(B i(u)) i were constructed using the direct method and the composite variational principle. Application of the method of classification of conservation laws with respect to the group of point transformations [R.O.~Popovych, N.M. Ivanova, J. Math. Phys. 46, 2005, 043502 (math-ph/0407008)] allows us to formulate the result in explicit closed form. Action of the symmetry groups on the conservation laws of diffusion equations is investigated and generating sets of conservation laws are constructed.

A full symmetry classification is given for models of energy transport in radiant plasma when the mass density is spatially variable and the diffusivity is nonlinear. A systematic search for conservation laws also leads to some potential symmetries, and to an integrable nonlinear model. Classical point symmetries, potential symmetries and nonclassical symmetries are used to effect variable reductions and exact solutions. The simplest time-dependent solution is shown to be stable, and relevant to a closed system., 13 pages. arXiv admin note: text overlap with arXiv:math-ph/0605081, arXiv:1101.4755 by other authors

In this paper, we discuss the operation of an OA SLM with amorphous hydrogenated silicon, utilised as a photo-semiconductor, and with a distorted-helix ferroelectric liquid crystal. The device operation is studied using a holographic technique in two modes: with pulsed and continuous recording. The dependence of the diffraction efficiency on the write-light intensity, spatial frequency, and on repetition rate of the write-light pulses is measured.

In this paper, we explain in more details the modern treatment of the problem of group classification of (systems of) partial differential equations (PDEs) from the algorithmic point of view. More precisely, we revise the classical Lie--Ovsiannikov algorithm of construction of symmetries of differential equations, describe the group classification algorithm and discuss the process of reduction of (systems of) PDEs to (systems of) equations with smaller number of independent variables in order to construct invariant solutions. The group classification algorithm and reduction process are illustrated by the example of the generalized Zakharov--Kuznetsov (GZK) equations of form $u_t+(F(u))_{xxx}+(G(u))_{xyy}+(H(u))_x=0$. As a result, a complete group classification of the GZK equations is performed and a number of new interesting nonlinear invariant models which have non-trivial invariance algebras are obtained. Lie symmetry reductions and exact solutions for two important invariant models, i.e., the classical and modified Zakharov--Kuznetsov equations, are constructed. The algorithmic framework for group analysis of differential equations presented in this paper can also be applied to other nonlinear PDEs., Comment: 25 pages

Second-order NLO characteristics of thin films based on model epoxy amine oligomers with 4-amino-4'-nitroazobenzene chromophore in the main chain, containing hydroxyl and methacryloyl groups, CFAO and CFMAO, respectively, are determined. Synthesized polymers possess high content of chromophore fragments and have good film-forming properties, which allowed one to cast homogeneous films of 200-400 nm thickness. The presence of reactive groups in the monomer units makes it possible to use cross-linking of polymer matrix to preserve the chromophores orientation order achieved in the course of corona poling and to provide relaxation stability of the second-order NLO response. Rather high values of the nonlinear optical coefficients estimated by second harmonic generation technique allow one to consider these epoxy amine polymers as promising candidates for the construction of cross-linked polymer matrices with long-term stability of the quadratic NLO response at elevated temperatures.

In the presented paper known (up to the beginning of 2008) Lie- and non-Lie exact solutions of different $(1+1)$-dimensional diffusion-convection equations of form $f(x)u_t=(g(x)A(u)u_x)_x+h(x)B(u)u_x$ are collected., Comment: version published at Dynamics of Partial Differential Equations (DPDE), Volume 5, No. 2

The electrochemical behavior of thin-film oxide-hydroxide electrodes containing chromium, nickel and cobalt compounds was investigated. Experimental results have shown that such compounds can be successfully used as active cathodic materials in a number of emerging primary and secondary battery applications.