Nucleation and growth of Cu onto polycrystalline Pt electrode from acidic CuSO4 solution in the presence of H2SeO3

The early stages of Cu electrodeposition onto Pt(poly) have been investigated in 0.5 M H₂SO₄ + 0.01 M CuSO₄ solution without or with H₂SeO₃ when a molar concentration ratio [Cu(II)]/[Se(IV)] ≥ 2×10² using electrochemical and ex situ AFM techniques. The overpotential deposition of Cu has been performed onto a Pt surface precovered independently with Cu in amount close to an equivalent monolayer. Chronoamperometric results have been shown to follow an instantaneous 3D nucleation and diffusion-controlled growth model. The values of diffusion coefficient D for Cu²⁺, number of nuclei N and average nuclei radius r _av have been calculated. In the local regions of the surface, the separate large agglomerates composed of the different diameter clusters have been revealed in both cases, but, in the presence of the H₂SeO₃, they attained a distinct chain-like configuration. Some morphological characteristics have been reported.     

Second order asymptotic behaviour of subordinated sequences with longtailed subordinator

Suppose that {a(n)} is a discrete probability distribution on the set N₀={0,1,2,…} and {p(n)} is some non-negative sequence defined on the same set. The equation defines a new sequence {b(n)}. Here {a*k(n)} denotes the k-fold convolution of the distribution {a(n)}. In the paper the asymptotic behaviour of the sequence {b(n)} is investigated. It is known that for the large classes of the sequences {a(n)} and {p(n)}, b(n)∼σp([σn]), where 1/σ is the mean of the distribution {a(n)}. The main object of the present work is to estimate the difference b(n)−σp([σn]) for some classes of the sequences {a(n)} and {p(n)}.     

Limit theorems for some polynomial statistics of the poisson process

The central limit theorem and the theorem on large deviations for the functionals of the Poisson random process are proved. The formulas for cumulants of multiple stochastic integrals (m.s.i.) with respect to the Poisson process are obtained. The m.s.i. may be considered as anU-statistics arising in queueing theory as well as a generalization of the well-known Poisson shot-noise process, having wide applications.     

Accuracy and robustness of three-way decomposition applied to NMR data

Three-way decomposition is a very versatile analysis tool with applications in a variety of protein NMR fields. It has been used to extract structural data from 3D NOESYs, to determine relaxation rates in large proteins, to identify ligand binding in screening for lead compounds, and to complement non-uniformly recorded (sparse) spectra. All applications so far concerned experimental data sets; it thus remains to address questions of accuracy and robustness of the method using simulated data where the correct answer is known. Systematic tests are presented for relaxation and NOESY data sets. Mixtures of real and synthetic data are used to allow control of various parameters and comparisons with correct reference data, while working with input that is as realistic as possible. The influence of the following parameters is evaluated: signal-to-noise, overlap of signals and the use of a regularization procedure within the algorithm. The main criteria used for the evaluation are accuracy and precision. It is shown that deterioration of accuracy is indicated by internal checks such as decrease of precision. Both with relaxation data and when interpreting NOESY spectra, three-way decomposition exhibits a robust behavior in situations with severe signal overlap and/or poor signal-to-noise, e.g., by avoiding false positives in the NOE shapes of NOESY decompositions. As a complement to this study, three-way decomposition is compared to other methods that achieve the same type of results.     

Assessing the Europe 2020 Strategy Implementation Using Interval Entropy and Cluster Analysis for Interrelation between Two Groups of Headline Indicators

The research analyzes the progress of Member States in the implementation of Europe 2020 strategy targets and goals in 2016–2018. Multiple criteria decision-making approaches applied for this task. The set of headline indicators was divided into two logically explained groups. Interval entropy is proposed as an effective tool to make prioritization of headline indicators in separate groups. The sensitivity of the interval entropy is its advantage over classical entropy. Indicator weights were calculated by applying the WEBIRA (weight-balancing indicator ranks accordance) method. The WEBIRA method allows the best harmonization of ranking results according to different criteria groups—this is its advantage over other multiple-criteria methods. Final assessing and ranking of the 28 European Union countries (EU-28) was implemented through the α-cut approach. A k-means clustering procedure was applied to the EU-28 countries by summarizing the ranking results in 2016–2018. Investigation revealed the countries–leaders and countries–outsiders of the Europe 2020 strategy implementation process. It turned out that Sweden, Finland, Denmark, and Austria during the three-year period were the countries that exhibited the greatest progress according to two headline indicator groups’ interrelation. Cluster analysis results are mainly consistent with the EU-28 countries’ categorizations set by other authors.     

Effect of H<Subscript>2</Subscript>SeO<Subscript>3</Subscript> on the early stages of nucleation and growth during Cu electrocrystallization in acidic medium on glassy carbon electrode

The early stages of Cu electrodeposition onto a GC electrode were investigated in 0.5 M H₂SO₄ + 0.01 M CuSO₄ solution without or with H₂SeO₃ when a molar concentration ratio [Cu(II)]/[Se(IV)] was 1.10⁴ to 2.10². The H₂SeO₃ solution in 0.5 M H₂SO₄ was also used. The electrochemical techniques such as cyclic voltammetry and chronoamperometry and structural investigation using ex situ AFM were applied to study the nucleation and growth of Cu onto a GC electrode. Chronoamperometric results were shown to follow an instantaneous 3D nucleation and diffusion-controlled growth model by Scharifker and Hills. The values of number of Cu nuclei N and average nuclei radius r _av were calculated. It was shown that, in the presence of H₂SeO₃ in amounts of 0.001 to 0.005 mM, N increases and r _av decreases. At higher concentrations of the additive, the changes of these parameters with the deposition potential E _dep were shown to be somewhat more complex. The dependences of N and r _av on the concentration of H₂SeO₃ in different regions of Cu overpotentials were also revealed.     

Calibrated Estimators of the Population Covariance

We introduce some calibrated estimators of a finite-population covariance. The estimators are defined by using different calibration equations and different loss functions. The estimators derived are compared by simulation. The study is supported by the Nordplus Neighbour program of the Nordic Council of Ministers.     

Accurate relaxation parameters for large proteins

The practical applicability, performance, and robustness of three-way decomposition (TWD) for the extraction of relaxation parameters are demonstrated for a large protein with 370 residues, the maltose binding protein. An ordinary set of seven relaxation-modulated (15)N HSQC spectra, recorded at another site, is systematically analyzed. For all 341 assigned backbone amide groups, including 21 pairs and one group of three overlapped peaks, T1 decay values were determined. On isolated peaks, TWD extracts T1 values with systematically lower error bounds compared to conventional tools, although for these simple cases the improvements remain limited. However, in the presence of spectral artifacts, the decrease in errors can become significant, demonstrating the higher robustness of TWD. For about half of the peaks in overlapped regions, the decomposition allowed separation of the signals, yielding significantly different T1 values between overlapping signals. For the rest, similarity of the decay times for the two or three overlapping signals could be confirmed within usually low error bounds. The use of TWD thus leads to a significant increase in the number of accessible relaxation probes in large proteins. With a newly implemented graphical user interface, the application of TWD requires merely a peak list, and thus no additional effort compared to conventional approaches is needed.