Design and experimental evaluation of a test rig for ultrasonic monitoring of sccelerated corrosion

The design of a test rig for ultrasonic monitoring of corroding steel samples and results of its experimental evaluation are presented. In order to accelerate and quantify corrosion, the monitored sample acts as an anode in a typical constant current electroplating setup. An Arduino-powered microcontroller is used to log the relevant voltage and current values on an SD card, and a high accuracy ultrasonic waveform acquisition instrument is employed to record the ultrasonic waveforms reflected form the corroding surface. Experimental assessment of the designed rig confirmed that it met the design objectives and could be used for experimental studies of accelerated corrosion in steel samples

Soliton absorption spectroscopy

We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width using the novel perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires spectral modulation that follows the associated index of refraction of the absorber. The model can be applied to ordinary soliton propagation and to an absorber inside a passively modelocked laser. In the latter case, a comparison with water vapor absorption in a femtosecond Cr:ZnSe laser yields a very good agreement with experiment. Compared to the conventional absorption measurement in a cell of the same length, the signal is increased by an order of magnitude. The obtained analytical expressions allow further improving of the sensitivity and spectroscopic accuracy making the soliton absorption spectroscopy a promising novel measurement technique.Comment: 9 pages, 7 figures

Photon and electron spectra in hot and dense QED

Photon and electron spectra in hot and dense QED are found in the high temperature limit for all |\q| using the Feynman gauge and the one-loop self-energy. All spectra are split by the medium and their branches develop the gap (the dynamical mass) at zero momentum. The photon spectrum has two branches (longitudinal and transverse) with the common mass; but electron spectrum is split on four branches which are well-separated for any |\q| including their |\q|=0 limits (their effective masses). These masses and the photon thermal mass are calculated explicitly and the different limits of spectrum branches are established in detail. The gauge invariance of the high-temperature spectra is briefly discussed.Comment: 9 pages, latex, no figure

Autonomous intrusion detection information system

Abstract – Implementation of security arrangements for insecure premises, for example, for temporary exhibitions or infrequent public events, usually results in substantial security personnel costs which can be potentially reduced by employing an easily installable ad hoc intrusion detection information system. In the paper we described the architecture, design and experimental results for a fully prototyped information system that utilizes ultrasonic sensors operating in the pulse echo mode for the perimeter control and ZigBee transceivers for wireless networking. The system consists of inexpensive autonomous sensor nodes with the component cost of less than £25 and a control terminal with a graphical user interface controlled by a touch screen. The nodes are programmed wirelessly to detect intrusion within any user set distance up to the operating distance of the node, and can operate unattended for days. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2877

Factors and conditions of functioning and development of modern regional socio-economic systems

Purpose: The purpose of this article is the systemic modernization of scientific ideas relating to the essential factors and conditions of functioning and development of regional socioeconomic systems. Design/Methodology/Approach: To substantiate the article about the possibility of overcoming the socio-economic stagnation and recession of the region's economy based on modernization of research tools and management of local and regional socio-economic processes using modern agglomerative technologies and methods. Findings: Finding lies in clarifying the arrangement, structure and importance of socioeconomic processes, factors and conditions of local, regional and interregional level that determine the effectiveness and sustainability of functioning of the economy. Practical Implications: Are determined by the possibility to use authors' scientific results for audit, evaluation and adjustment of regional socio-economic impacts, measures and development programs, used during designing, forecast and assessment of socio-economic and complex efficiency of local and regional socio-economic activeness in the cities and municipal areas. Originality / Value: It is substantiated by development of the theory and methodology of regional studies of socio-economic factors and conditions that determine long-term prospects of stable functioning and sustainable development of the regional economy on the basis of adaptation of the basic direction of the system and reproduction processes.peer-reviewe

Determination of the UV cut-off from the observed value of the Universe acceleration

It is shown that using of the equation of motion of the Universe scale factor allows calculation of the contribution of the vacuum fluctuations to the acceleration of the Universe expansion. Renormalization of the equation is needed only in the case of massive particles. Under a known number of the different kinds of fundamental fields, this provides determination of momentum of the ultraviolet cut-off from the observed value of acceleration.Comment: 10 pages, 1 figur

Invariant Sets and Explicit Solutions to a Third-Order Model for the Shearless Stratified Turbulent Flow

We study dynamics of the shearless stratified turbulent flows. Using the method of differential constraints we find a class of explicit solutions to the problem under consideration and establish that the differential constraint obtained coincides with the well-known Zeman--Lumley model for stratified flows.Comment: arxiv version is already officia

Non-Abelian Collective Excitations in Unlinearized Quark-Gluon Plasma Media

We study the effect of unlinearized medium on the collective excitations in quark-gluon plasma. We present two kinds of non-Abelian oscillation solutions which respectively correspond to weakly and strongly nonlinear coupling of field components in color space. We also show that the weakly nonlinear solution is similar to Abelian-like one but has the frequency shift, which is of order $g^2T$, from eigenfrequency.Comment: 7 page

Mathematical analysis of a model of river channel formation.

The study of overland flow of water over an erodible sediment leads to a coupled model describing the evolution of the topographic elevation and the depth of the overland water film. The spatially uniform solution of this model is unstable, and this instability corresponds to the formation of rills, which in reality then grow and coalesce to form large-scale river channels. In this paper we consider the deduction and mathematical analysis of a deterministic model describing river channel formation and the evolution of its depth. The model involves a degenerate nonlinear parabolic equation (satisfied on the interior of the support of the solution) with a super-linear source term and a prescribed constant mass. We propose here a global formulation of the problem (formulated in the whole space, beyond the support of the solution) which allows us to show the existence of a solution and leads to a suitable numerical scheme for its approximation. A particular novelty of the model is that the evolving channel self-determines its own width, without the need to pose any extra conditions at the channel margin