Corrosion Behavior of Composite Coatings Obtained by Electrolytic Codeposition of Copper with Al2O3 Nanoparticles

Composite coatings of copper incorporating Al2O3 nanoparticles electrodeposited on carbon steel were obtained and characterized. By using electrochemical methods such as open circuit potential (ocp) measurements, polarization curves and electrochemical impedance spectroscopy, the corrosion behavior of the Al2O3-copper nanocomposite coatings was examined. The corrosion parameters determined from the polarization curves recorded in Na2SO4 solution (pH 3) indicate that the corrosion process on copper-Al2O3 composite surface is slower than on pure copper. The impedance spectra recorded at the ocp showed in all cases an increase of the polarization resistance in time, which may be explained by the development of corrosion products on the electrode surface. Using a (2RC) equivalent electrical circuit, the process parameters were estimated by non-linear regression calculations with a Simplex method. The Al2O3 particles embedded in the electroplated copper, increase the polarization resistance and decrease the corrosion rates as compared with electrodeposited pure copper. The electrochemical results were corroborated with those obtained by SEM and EDX investigations

Learning the tensor network model of a quantum state using a few single-qubit measurements

The constantly increasing dimensionality of artificial quantum systems demands for highly efficient methods for their characterization and benchmarking. Conventional quantum tomography fails for larger systems due to the exponential growth of the required number of measurements. The conceptual solution for this dimensionality curse relies on a simple idea - a complete description of a quantum state is excessive and can be discarded in favor of experimentally accessible information about the system. The probably approximately correct (PAC) learning theory has been recently successfully applied to a problem of building accurate predictors for the measurement outcomes using a dataset which scales only linearly with the number of qubits. Here we present a constructive and numerically efficient protocol which learns a tensor network model of an unknown quantum system. We discuss the limitations and the scalability of the proposed method.Comment: 10 pages, 11 figure

TWIK-related acid-sensitive potassium channels (TASK-1) emerge as contributors to tone regulation in renal arteries at alkaline pH

Aim: TASK-1 channels are established regulators of pulmonary artery tone but their contribution to the regulation of vascular tone in systemic arteries is poorly understood. We tested the hypothesis that TASK-1 channel functional impact differs among systemic vascular beds, that this is associated with differences in their expression and may increase with alkalization of the extracellular environment. Therefore, we evaluated the expression level of TASK-1 channels and their vasomotor role in mesenteric and renal arteries. Methods: Pulmonary, mesenteric and renal arteries from male Wistar rats were used for TASK-1 channel mRNA (qPCR) and protein content (Western blotting) measurements. The functional role of TASK-1 channels was studied by wire myography using the TASK-1 channel blocker AVE1231. In some experiments, the endothelium was removed with a rat whisker. Results: Expression levels of both mRNA and protein of the TASK-1 channel pore-forming subunit were highest in pulmonary arteries, lowest in mesenteric arteries and had an intermediate value in renal arteries. Blockade of TASK-1 channels by 1 µM AVE1231 increased U46619-induced contractile responses of pulmonary arteries but did not affect basal tone and contractile responses to methoxamine of mesenteric and renal arteries at physiological extracellular pH (pHo = 7.41). At alkaline extracellular pH = 7.75 (increase of NaHCO3 to 52 mM) AVE1231 evoked the development of basal tone and increased contractile responses to low concentrations of methoxamine in renal but not mesenteric arteries. This effect was independent of the endothelium. Conclusion: In the rat systemic circulation, TASK-1 channels are abundant in renal arteries and have an anticontractile function under conditions of extracellular alkalosis

On Certain Aspects of Dembo-Rubinstein Method of Self-esteem Measurement

AbstractA variety of techniques for studying self-esteem and a wide range of studies reflect the high importance of this phenomenon at all stages of ontogeny, especially in the period of growth and development. One of the most common approaches to self-esteem measurement is the scale of Dembo-Rubinstein. Currently Dembo-Rubinstein scale has several different modifications. According to one of them subjects are asked about both their actual self-esteem and its desired level. It is assumed that in this way the level of individual claims can be estimated. The aim of the following research is to assess the correlation between the actual and desired levels of self-esteem and on this basis to draw the conclusion concerning the usefulness of this modification of the method

Investigating human mitochondrial genomes in single cells

Mitochondria host multiple copies of their own small circular genome that has been extensively studied to trace the evolution of the modern eukaryotic cell and discover important mutations linked to inherited diseases. Whole genome and exome sequencing have enabled the study of mtDNA in a large number of samples and experimental conditions at single nucleotide resolution, allowing the deciphering of the relationship between inherited mutations and phenotypes and the identification of acquired mtDNA mutations in classical mitochondrial diseases as well as in chronic disorders, ageing and cancer. By applying an ad hoc computational pipeline based on our MToolBox software, we reconstructed mtDNA genomes in single cells using whole genome and exome sequencing data obtained by different amplification methodologies (eWGA, DOP-PCR, MALBAC, MDA) as well as data from single cell Assay for Transposase Accessible Chromatin with high-throughput sequencing (scATAC-seq) in which mtDNA sequences are expected as a byproduct of the technology. We show that assembled mtDNAs, with the exception of those reconstructed by MALBAC and DOP-PCR methods, are quite uniform and suitable for genomic investigations, enabling the study of various biological processes related to cellular heterogeneity such as tumor evolution, neural somatic mosaicism and embryonic development

A correlation between deformation-induced surface roughness and in-plane plastic strain in an aluminum alloy at the mesoscale

cal studies on deformation-induced surface roughening in a commercial purity aluminum alloy are presented and discussed. Mesoscale surface profiles evolving in the experimental and numerical specimens in the course of tension are processed to reveal a correlation between roughness characteristics and in-plane plastic strains at the mesoscale. A dimensionless parameter calculated as a ratio of the rough profile length to the profile evaluation length has been used for quantitative estimations of the mesoscale roughness patterns. The dimensionless roughness parameter is shown to depend exponentially on the in-plane plastic strains at the mesoscale. The results support an early assumption tha

Mechanical aspects of nonhomogeneous deformation of aluminum single crystals under compression along [100] and [110] directions

The deformation behavior of aluminum single crystals subjected to compression along the [100] and [110] directions is numerically examined in terms of crystal plasticity. A constitutive model taking into account slip geometry in face-centered cubic crystals is developed using experimental data for the single-crystal samples with lateral sides coplanar to certain crystal planes. Two sets of calculations are performed using ABAQUS/Explicit to examine the features of plastic strain evolution in perfectly plastic and strain-hardened crystals. Special attention is given to the discussion of mechanical aspects of crystal fragmentation. Several distinct deformation stages are revealed in the calculations. In the first stage, narrow solitary fronts of plastic deformation are alternately formed near the top or bottom surfaces and then propagate towards opposite ends to save the symmetry of the crystal shape. The strain rate within the fronts is an order of magnitude higher than the average strain rate. The first stage lasts longer in the strain-hardened crystals, eventually giving way to an intermediate stage of multiple slips in different crystal parts. Finally, the crystal shape becomes asymmetrical, but no pronounced macroscopic strain localization has been revealed at any deformation stage. The second stage in perfectly plastic crystals relates to abrupt strain localization within a through-thickness band-shaped region, accompanied by macroscale crystal fragmentation. Stress analysis has shown that pure compression took place only in the first deformation stage. Once the crystal shape has lost its symmetry, the compressive stress in some regions progressively decreases to zero and eventually turns tensile

A glossy magazine discourse of the early twenty-first century as a tool of globalization: Sochi school of linguistics and rhetoric

The authors consider the discourse of a glossy magazine. They highlight the glossy magazine discourse, which appears in the framework of the General media discourse as an institutional discourse from the standpoint of the linguistical-rhetorical paradigm (LRP) of the Sochi scientific school. This type of discourse is a discursive process of a special type, acts as an explicit tool of globalization. The authors emphasize the novelty of this discourse in the context of its influence on the formation and transformation of the modern linguistic personality. The relevance of the study is emphasized by the fact that the glossy magazine discourse is the latest in terms of the chronology of the historical process. In addition, he actualizes the poly-ethno-socio-cultural and educational space (PESCES) of the beginning of the XXI century, on the example of glossy magazine discourse practices in Russia. For the first time, Glossy magazine discourse stimulates transformations in line with the leading trend of the formation of the "planetary language personality (PLP)" - globalization in the value orientations of the "philosophy of glamour"