The influence of alkaline treatment on the chemical composition and adsorption-structural characteristics of mineral nanoporous sorbent M<Subscript>45</Subscript>K<Subscript>20</Subscript>

The chemical and adsorption-structural properties of natural nanoporous mineral sorbent M₄₅C₂₀ having two main components (clay-montmorillonite and zeolite-clinoptilolite) and treated with 2M NaOH solution are investigated. It is ascertained based on the results of chemical analysis, X-ray diffraction, electron microscopy, and IR spectrometry that alkali treatment results in modification of the chemical composition and structure of the mineral sorbent M₄₅C₂₀ and significantly improves its adsorption properties.     

Using Ideas of Kolmogorov Complexity for Studying Biological Texts

Kolmogorov complexity furnishes many useful tools for studying different natural processes that can be expressed using sequences of symbols from a finite alphabet (texts), such as genetic texts, literary and music texts, animal communications, etc. Although Kolmogorov complexity is not algorithmically computable, in a certain sense it can be estimated by means of data compressors. Here we suggest a method of analysis of sequences based on ideas of Kolmogorov complexity and mathematical statistics, and apply this method to biological (ethological) ??texts.?? A distinction of the suggested method from other approaches to the analysis of sequential data by means of Kolmogorov complexity is that it belongs to the framework of mathematical statistics, more specifically, that of hypothesis testing. This makes it a promising candidate for being included in the toolbox of standard biological methods of analysis of different natural texts, from DNA sequences to animal behavioural patterns (ethological ??texts??). Two examples of analysis of ethological texts are considered in this paper. Theses examples show that the proposed method is a useful tool for distinguishing between stereotyped and flexible behaviours, which is important for behavioural and evolutionary studies.     

Contract-theoretic Approach for Delay Constrained Offloading in Vehicular Edge Computing Networks

Mobile Networks and Applications - Mobile Edge Computing (MEC) is a promising solution to improve vehicular services through offloading computation to cloud servers in close proximity to mobile...     

On conclusive eavesdropping and measures of mutual information in quantum key distribution

We address the question of quantifying eavesdropper’s information gain in an individual attack on systems of quantum key distribution. It is connected with the concept of conclusive eavesdropping introduced by Brandt. Using the BB84 protocol, we examine the problem of estimating a performance of conclusive entangling probe. The question of interest depends on the choice of a quantitative measure of eavesdropper’s information about the error-free sifted bits. The Fuchs–Peres–Brandt probe realizes a very powerful individual attack on the BB84 scheme. In the usual formulation, Eve utilizes the Helstrom scheme in distinguishing between the two output probe states. In conclusive eavesdropping, the unambiguous discrimination is used. Comparing these two versions allows to demonstrate serious distinctions between widely used quantifiers of mutual information. In particular, the so-called Rényi mutual information does not seem to be a completely legitimate measure of an amount of mutual information. It is brightly emphasized with the example of conclusive eavesdropping.     

On Odd-periodic Orbits in Complex Planar Billiards

The famous conjecture of V. Ya. Ivrii (1978) says that in every billiard with infinitely-smooth boundary in a Euclidean space the set of periodic orbits has measure zero. In the present paper, we study the complex version of Ivrii’s conjecture for odd-periodic orbits in planar billiards, with reflections from complex analytic curves. We prove positive answer in the following cases: (1) triangular orbits; (2) odd-periodic orbits in the case, when the mirrors are algebraic curves avoiding two special points at infinity, the so-called isotropic points. We provide immediate applications to k-reflective real analytic pseudo-billiards with odd k, the real piecewise-algebraic Ivrii’s conjecture and its analogue in the invisibility theory: Plakhov’s invisibility conjecture.     

Synthesis of lithium cobaltate in halide melts

A new method for the synthesis of lithium cobaltate LiCoo₂ in salt melts is proposed and tested. The method is based on the oxidation of halide ions with molecular oxygen in LiX-CoCl₂ mixtures (X = Cl, Br, I). The chemical and phase compositions of the prepared powders and the crystal structure of the synthesized compound are studied by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The average size of LiCoO₂ crystallites is estimated from the X-ray diffraction data.     

Nanoscopic imaging of oxidized graphene monolayer using tip-enhanced Raman scattering

Nano Research - Tip-enhanced Raman scattering (TERS) can be used for the structural and chemical characterization of materials with a nanoscale resolution, and offers numerous advantages compared...