Self-amplified Emission of Cherenkov Radiation from a Relativistic Particle Inside Layered Dielectric-filled Waveguide

It is shown that in some special cases the Cherenkov radiation from a charged particle moving along the axis of cylindrical waveguide filled with a semi-infinite material consisting of dielectric plates alternated with vacuum gaps is many times stronger than that in the waveguide filled with semi-infinite solid dielectric without vacuum gaps.Comment: 1 page, abstract submitted to 4th International Conference "Channeling 2010", Ferrara, Italy, October 3-8, 201

On the detection of point sources in Planck LFI 70 GHz CMB maps based on cleaned K-map

We use the Planck LFI 70GHz data to further probe point source detection technique in the sky maps of the cosmic microwave background (CMB) radiation. The method developed by Tegmark et al. for foreground reduced maps and the Kolmogorov parameter as the descriptor are adopted for the analysis of Planck satellite CMB temperature data. Most of the detected points coincide with point sources already revealed by other methods. However, we have also found 9 source candidates for which still no counterparts are known.Comment: 11 pages, 3 figures, Accepted for publication in Modern Physics Letters A. arXiv admin note: substantial text overlap with arXiv:1206.712

Spatial Investigation of Mineral Transportation Characteristics in the State of Washington

This study investigates the spatial relationships between construction aggregate shipments and the per axle payload weights of trucks as they pertain to highway deterioration in the state of Washington. A previous study investigated the transportation characteristics of mined aggregates using a spatial autoregressive model, where a significant positive relationship between payload weights and shipment distances was established. This paper expands the previous study by assessing the contribution of aggregate hauling trucks to pavement deterioration using per-axle loads by truck configuration. Results showed a positive relationship between weights per axle load and several shipment distance categories. According to the well-established per axle weight and pavement damage relationship, incremental changes in per axle payload weights resulting from longer shipment distances clearly suggest that longer haulage increases the magnitude of pavement deterioration. This direct relationship between road impact and the distance hauled emphasizes the importance of the proximity of mine sites to different end users

Radiation from a charged particle-in-flight from a laminated medium to vacuum

The radiation from a charged particle-in-flight from a semi-infinite laminated medium to vacuum and back,- from vacuum to the laminated medium, has been investigated. Expressions for the spectral-angular distribution of radiation energy in vacuum (at large distances from the boundary of laminated medium) were obtained for both the cases with no limitations on the amplitude and variation profile of the laminated medium permittivity. The results of appropriate numerical calculations are presented and possible applications of the obtained results are discussed.Comment: 8 pages, 6 figures, contribution to Proceedings of International Symposium RREPS-2009, 07-11 September, 2009, Zvenigorod, Russi

On the theory of coherent pair production in crystals in presence of acoustic waves

The influence of hypersonic waves excited in a single crystal is investigated on the process of electron-positron pair creation by high-energy photons. The coherent part of the corresponding differential cross-section is derived as a function of the amplitude and wave number of the hypersound. The values of the parameters are specified for which the latter affects remarkably on the pair creation cross-section. It is shown that under certain conditions the presence of hypersonic waves can result in enhancement of the process cross-section.Comment: 10 pages, 3 EPS figure

To the center of cold spot with Planck

The structure of the cold spot, of a non-Gaussian anomaly in the cosmic microwave background (CMB) sky first detected by Vielva et al. is studied using the data by Planck satellite. The obtained map of the degree of stochasticity (K-map) of CMB for the cold spot, reveals, most clearly in 100 GHz band, a shell-type structure with a center coinciding with the minima of the temperature distribution. The shell structure is non-Gaussian at a 4\sigma confidence level. Such behavior of the K-map supports the void nature of the cold spot. The applied method can be used for tracing voids that have no signatures in redshift surveys.Comment: A & A (in press), 4 pages, 5 figures; to match the published versio