Spatial focus for UWB signals

Method of focus in the time domain and its analogue, a method of radiowave tomosynthesis in the frequency domain by the criterion of level artifacts in the reconstructed radio images of the test object are compared. To verify the advantages of focus in the time domain method numerical model of clocked nonequidistant flat antenna array has been developed at the Department of Radio Physics at Tomsk State University

Electron Clusters in Inert Gases

The paper addresses counterintuitive behavior of electrons injected into dense cryogenic media with negative scattering length $a_0$. Instead of expected polaronic effect (formation of density enhancement clusters) which should substantially reduce the electron mobility, an opposite picture is observed: with increasing $|a_0|$ (the trend taking place for inert gases with the growth of atomic number) and the medium density, the electrons remain practically free. An explanation of this behaviour is provided based on consistent accounting for the non-linearity of electron interaction with the gaseous medium in the gas atom number density

A comprehensive study of underground animals habitat

This paper describes a method of studying the natural habitats of underground animals by the example of zokor. The purpose of the research is to find habitation of animals using unmanned aircraft and investigate networks of tunnels and burrows with ground penetrating radar "OKO-2". Geolocation data were processed by techniques developed by the authors

Representations of (2,n)(2,n)-semigroups by multiplace functions

We describe the representations of $(2,n)$-semigroups, i.e. groupoids with $n$ binary associative operations, by partial $n$-place functions and prove that any such representation is a union of some family of representations induced by Schein's determining pairs.Comment: 17 page

Water adsorption on acetylene black carbon

Differential heat, isotherm, thermokinetics, and entropy of water adsorption on the black carbon were studied by the adsorption-calorimetric method at 303 K. The adsorption mechanism, type, and number of formed ion-molecular complexes were determined. Thermokinetics of adsorption on the black carbon and the law of migration of exchange cations were determined, and the adsorption energy of gases and vapors was calculated. The adsorption isotherm is described by the two-and three-dimensional mathematical equations of the volume-saturation theory of micro-pores (TVSM)

Representations of Menger (2,n)(2,n)-semigroups by multiplace functions

Investigation of partial multiplace functions by algebraic methods plays an important role in modern mathematics were we consider various operations on sets of functions, which are naturally defined. The basic operation for $n$-place functions is an $(n+1)$-ary superposition $[ ]$, but there are some other naturally defined operations, which are also worth of consideration. In this paper we consider binary Mann's compositions \op{1},...,\op{n} for partial $n$-place functions, which have many important applications for the study of binary and $n$-ary operations. We present methods of representations of such algebras by $n$-place functions and find an abstract characterization of the set of $n$-place functions closed with respect to the set-theoretic inclusion

Application of broadband microwave near-field sensors for glucose monitoring in biological media

The paper presents results of numerical simulation and experimental testing of a microwave sensor for non-invasive glucose monitoring. The sensor represents a conical horn with a conical conductor inside expanding toward the horn aperture. Such a sensor has a significantly wider passband in comparison with sensors of other designs. It is essential that the sensor geometry provides formation of an extended near-field zone with high electric field strength near the sensor aperture. A clear relationship between the dielectric permittivity of the phantom biological tissue and the frequency dependence of the parameter S11 of the sensor is observed at frequencies in the range from 1.4 to 1.7 GHz. This circumstance can be used to develop a procedure for measuring the glucose level in blood that correlates with the parameter S11 of the sensor. From the viewpoint of monitoring of the glucose content in blood, the most convenient body sensor location is on the hands or feet, in particular, wrists