Self-Consistent Screening Approximation for Flexible Membranes: Application to Graphene

Crystalline membranes at finite temperatures have an anomalous behavior of the bending rigidity that makes them more rigid in the long wavelength limit. This issue is particularly relevant for applications of graphene in nano- and micro-electromechanical systems. We calculate numerically the height-height correlation function $G(q)$ of crystalline two-dimensional membranes, determining the renormalized bending rigidity, in the range of wavevectors $q$ from $10^{-7}$ \AA$^{-1}$ till 10 \AA$^{-1}$ in the self-consistent screening approximation (SCSA). For parameters appropriate to graphene, the calculated correlation function agrees reasonably with the results of atomistic Monte Carlo simulations for this material within the range of $q$ from $10^{-2}$ \AA$^{-1}$ till 1 \AA$^{-1}$. In the limit $q\rightarrow 0$ our data for the exponent $\eta$ of the renormalized bending rigidity $\kappa_R(q)\propto q^{-\eta}$ is compatible with the previously known analytical results for the SCSA $\eta\simeq 0.82$. However, this limit appears to be reached only for $q<10^{-5}$ \AA$^{-1}$ whereas at intermediate $q$ the behavior of $G(q)$ cannot be described by a single exponent.Comment: 5 pages, 4 figure

The innovative technologies of education in the higher economic education of Ukraine

The article deals with the problem of professional training of future specialists in economics to work in the foreign exchange market based on the MetaStock computer program. The aim of the article is to reveal the peculiarities of the technical methods of preparing future economists for the testing of trading systems based on the software product such as MetaStock. The algorithms of students work with the MetaStock computer program with the aim of acquiring skills in the currency market based on computer technologies are determined. It is determined that the prerequisite for successful professional activity in the foreign exchange market is the mastery by future economists of their professional knowledge, skills and skills of trading systems testing while using the MetaStock computer program. It was proved with the help of experiments that the implementation of these methods of training of future economic specialists for testing trading systems based on the computer program MetaStock has led to a significant increase of their readiness to work in the currency market on the basis of computer technology.peer-reviewe

Diagnostics of formedness of system of values of future economists in professional preparation process

The article presents the results of the diagnostics of the formation of the value sphere of future economists. The problem of diagnostics of the formedness of the axiosphere of future economic profile specialist is becoming increasingly relevant in the context of modern socio-economic and political conditions. The notion of "value" is considered in the article as a material or spiritual object, which matters for a particular person and causes a valuable relation to it. We define the valuable orientations of the person as a relatively stable orientation of the needs of an individual towards a certain group of values. The purpose of the research is to carry out the diagnostics of the formation of the value sphere of future specialists of the economic profile. Students studying economics on 1-3 courses participated in the study. The methods of conversations, interviews, questionnaires, and observations were used to diagnose the formedness of the value sphere of future specialists in the economic field in the process of carrying out their vocational training. The conducted research testifies to the formedness of certain social image of democratic and totalitarian values of future economic specialists. However, there is a need for further work on clarifying the essence of such socially important values as discipline and law-abidingness and the formation of proper awareness of them by future economists. The development of a methodology for formation of the value sphere of the future specialist in the economic profile is the prospects for further research.peer-reviewe

Atomistic simulations of structural and thermodynamic properties of bilayer graphene

We study the structural and thermodynamic properties of bilayer graphene, a prototype two-layer membrane, by means of Monte Carlo simulations based on the empirical bond order potential LCBOPII. We present the temperature dependence of lattice parameter, bending rigidity and high temperature heat capacity as well as the correlation function of out-of-plane atomic displacements. The thermal expansion coefficient changes sign from negative to positive above $\approx 400$ K, which is lower than previously found for single layer graphene and close to the experimental value of bulk graphite. The bending rigidity is twice as large than for single layer graphene, making the out-of-plane fluctuations smaller. The crossover from correlated to uncorrelated out-of-plane fluctuations of the two carbon planes occurs for wavevectors shorter than $\approx 3$ nm$^{-1}$Comment: 6 pages, 7 figures

Digestion and metability in the human body

Today, the process of digestion is well known. This was made possible thanks to the efforts of scientists who have tried for many years to figure out what happens in the body when we swallow food. This involuntary process has been a mystery for a very long tim