THE PROCEDURES OF VISUAL ANALYSIS FOR MULTIDIMENSIONAL DATA VOLUMES

The paper is devoted to problems of visual analysis of multidimensional data sets using an approach based on the construction of elastic maps. This approach is quite suitable for processing and visualizing of multidimensional datasets. The elastic maps are used as the methods of original data points mapping to enclosed manifolds having less dimensionality. Diminishing the elasticity parameters one can design map surface which approximates the multidimensional dataset in question much better. Then the points of dataset in question are projected to the map. The extension of designed map to a flat plane allows one to get an insight about the structure of multidimensional dataset. The paper presents the results of applying elastic maps for visual analysis of multidimensional data sets of medical origin. Previously developed data processing procedures are applied to improve the results obtained - pre-filtering of data, removal of separated clusters (flotation), quasi-Zoom

Current Visualization Trends in CFD Problems

Abstract The paper presents authors view at the current trends of visualization in CFD (computational fluid dynamics) problems. The main factors of influence defining these trends are considered. Some examples of methods synthesis for better insight of numerical experiments data are enclosed. Also the prospects of such synthesis applying to construction of generalized experiment are discussed. Mathematics Subject Classification: 76N25, 76M27, 65Y0

Triboelectric Backgrounds to radio-based UHE Neutrino Exeperiments

The triboelectric effect broadly includes any process in which force applied at a boundary layer results in displacement of surface charge, leading to the generation of an electrostatic potential. Wind blowing over granular surfaces, such as snow, can induce a potential difference, with subsequent coronal discharge. Nanosecond timescale discharges can lead to radio-frequency emissions with characteristics similar to piezoelectric-induced discharges. For Antarctic-sited experiments seeking detection of radio-frequency signals generated by collisions of cosmic rays or neutrinos with atmospheric or englacial molecular targets, triboelectric emissions from the surface pose a potential background. This is particularly true for experiments in which radio antennas are buried ~(1--100) m below the snow surface, and seeking to validate neutrino detection strategies by measurement of down-coming radio-frequency emissions from extensive air showers. Herein, after summarizing extant evidence for wind-induced triboelectric effects previously reported elsewhere, we detail additional analysis using archival data collected with the RICE and AURA experiments at the South Pole. We broadly characterize those radio-frequency emissions based on source location, and time-domain and also frequency-domain characteristics. We find that: a) For wind velocities in excess of 10-12 m/s, triboelectric background triggers can dominate data-taking, b) frequency spectra for triboelectric events are generally shifted to the low-end of the regime to which current radio experiments are typically sensitive (100-200 MHz), c) there is an apparent preference for tribo-electric discharges from metal surface structures, consistent with a model in which localized, above-surface structures provide a repository for transported charge

The Nucleon-Mass Difference in Chiral Perturbation Theory and Nuclear Forces

A new method is developed for treating the effect of the neutron-proton mass difference in isospin-violating nuclear forces. Previous treatments utilized an awkward subtraction scheme to generate these forces. A field redefinition is used to remove that mass difference from the Lagrangian (and hence from asymptotic nucleon states) and replace its effect by effective interactions. Previous calculations of static Class II charge-independence-breaking and Class III charge-symmetry-breaking potentials are verified using the new scheme, which is also used to calculate Class IV nuclear forces. Two-body forces of the latter type are found to be identical to previously obtained results. A novel three-body force is also found. Problems involving Galilean invariance with Class IV one-pion-exchange forces are identified and resolved.Comment: 20 pages, 2 figures, latex - submitted to Physical Review

Spontaneous decay dynamics in atomically doped carbon nanotubes

We report a strictly non-exponential spontaneous decay dynamics of an excited two-level atom placed inside or at different distances outside a carbon nanotube (CN). This is the result of strong non-Markovian memory effects arising from the rapid variation of the photonic density of states with frequency near the CN. The system exhibits vacuum-field Rabi oscillations, a principal signature of strong atom-vacuum-field coupling, when the atom is close enough to the nanotube surface and the atomic transition frequency is in the vicinity of the resonance of the photonic density of states. Caused by decreasing the atom-field coupling strength, the non-exponential decay dynamics gives place to the exponential one if the atom moves away from the CN surface. Thus, atom-field coupling and the character of the spontaneous decay dynamics, respectively, may be controlled by changing the distance between the atom and CN surface by means of a proper preparation of atomically doped CNs. This opens routes for new challenging nanophotonics applications of atomically doped CN systems as various sources of coherent light emitted by dopant atoms.Comment: 10 pages, 4 figure

MOISTURE CONTENT OF NATURAL GAS IN BOTTOM HOLE ZONE

For the traditional problem of gas flow to a well in the center of circular reservoir, the influence of initial reservoir conditions on dynamics of gas moisture content distribution has been determined. Investigations have been performed in the framework of mathematical model of non-isothermal real gas flow through porous media where heat conductivity was considered to be negligible in comparison with convective heat transfer. It is closed by empirical correlation of compressibility coefficient with pressure and temperature, checked in previous publications. Functional dependence of moisture content in gas on pressure and temperature is based on empirical modification of Bukacek relation. Numerical experiment was performed in the following way. At first step, axisymmetric problem of non-isothermal flow of real gas in porous media was solved for a given value of pressure at the borehole bottom, which gives the values of pressure and temperature as functions of time and radial coordinate. Conditions at the outer boundary of the reservoir correspond to water drive regime of gas production. At the second step, the calculated functions of time and coordinate were used to find the analogous function for moisture content. The results of experiment show that if reservoir temperature essentially exceeds gas – hydrate equilibrium temperature than moisture content in gas distribution is practically reflects the one of gas temperature. In the opposite case, gas will contain water vapor only near  bottom hole and at the rest of reservoir it will be almost zero. In both cases, pressure manifests its role through the rate of gas production, which in turn influences convective heat transfer and gas cooling due to throttle effect

Study of antimicrobial activity and technology optimization of Calendulae flos galenicals

The article presents materials on optimization of manufacture technology for Calendulae flos galenicals with medium level of antibacterial activity. For antibacterial study of extracts, we used agar well diffusion method. In our research, we utilized six test-strain microorganisms: E. coli ATCC 25922, S. aureus ATCC 25923, P. vulgaris ATCC 4636, P. aeruginosa ATCC 27853, C. albicans ATCC 885/653, and B. subtilis ATCC 6633. We have found that the maximum level of extracts’ antimicrobial activity is achieved in the range of ethanol content in the extractant from 70 to 97 % v/