X-ray verification of the possibility of the mandible articular head restoration: A clinical case

Improvement of the methods of diagnosis and treatment of temporomandibular joint (TMJ) dysfunction is of prime importance in increasing the efficacy of orthopedic treatment. The aim of the study was to prove the possibility of TMJ structures restoration in the normalization of the lower jaw position during orthopedic treatment. The study confirmed the need to normalize the interalveolar height, to form multiple contacts for the antagonizing lateral teeth that allow to eliminate both joint heads distal displacement and bilaminar zone compression and, consequently, to reduce degenerative changes in TMJ joint

The supercritical accretion disk in SS433 and ultraluminous X-ray sources

SS433 is the only known persistent supercritical accretor, it may be very important for understanding ultraluminous X-ray sources (ULXs) located in external galaxies. We describe main properties of the SS433 supercritical accretion disk and jets. Basing on observational data of SS433 and published 2D simulations of supercritical accretion disks we estimate parameters of the funnel in the disk/wind of SS 433. We argue that the UV radiation of the SS433 disk (~50000 K, ~10^{40}erg/s) is roughly isotropic, but X-ray radiation (~10^7 K, ~10^{40}erg/s) of the funnel is midly anisotropic. A face-on SS433 object has to be ultraluminous in X-rays (10^{40-41}erg/s). Typical time-scales of the funnel flux variability are estimated. Shallow and very broad (0.1-0.3c) and blue-shifted absorption lines are expected in the funnel X-ray spectrum.Comment: 4 pages, 2 figures; Proceedings of IAUS23

Broad band variability of SS433: Accretion disk at work?

We present broad band power spectra of variations of SS433 in radio, optical and X-ray spectral bands. We show that at frequencies lower than 10 -5 Hz the source demonstrates the same variability pattern in all these bands. The broad band power spectrum can be fitted by one power law down to frequencies ∼10-7 Hz with flattening afterwards. Such a flattening means that on time scales longer than ∼107 s the source variability becomes uncorrelated. This naturally leads to the appearance of quasi-poissonian flares in the source light curve, which have been regularly observed in radio and optical spectral bands. The radio flux power spectrum appears to have a second break at Fourier frequencies ∼10-5 Hz which can be caused by the smearing of the intrinsic radio variability on timescale of the light-crossing time of the radio emitting region. We find a correlation of the radio and optical fluxes of SS433 and the radio flux is delayed by about ∼2 days with respect to the optical one. Power spectra of optical and X-ray variabilities continue with the same power law from 10 -7 Hz up to ∼0.01-0.05 Hz. The broad band power spectrum of SS433 can be interpreted in terms of self-similar accretion rate modulations in the accretion disk proposed by Lyubarskii (1997, MNRAS, 292, 679) and elaborated by Churazov et al. (2001, MNRAS, 321, 759). We discuss a viscous time-scale in the accretion disk of SS433 with reference to the observed broad band power spectrum. © ESO 2006

Broad band variability of SS433: Accretion disk at work?

We present broad band power spectra of variations of SS433 in radio, optical and X-ray spectral bands. We show that at frequencies lower than 1e-5 Hz the source demonstrates the same variability pattern in all these bands. The broad band power spectrum can be fitted by one power law down to frequencies ~1e-7 Hz with flattening afterwards. Such a flattening means that on time scales longer than ~1e7 sec the source variability becomes uncorrelated. This naturally leads to the appearance of quasi-poissonian flares in the source light curve, which have been regularly observed in radio and optical spectral bands. The radio flux power spectrum appears to have a second break at Fourier frequencies ~1e-5 Hz which can be caused by the smearing of the intrinsic radio variability on timescale of the light-crossing time of the radio emitting region. We find a correlation of the radio and optical fluxes of SS433 and the radio flux is delayed by about ~2 days with respect to the optical one. Power spectra of optical and X-ray variabilities continue with the same power law from 1e-7 Hz up to ~0.01-0.05 Hz. The broad band power spectrum of SS433 can be interpreted in terms of self-similar accretion rate modulations in the accretion disk proposed by Lyubarskii (1997) and elaborated by Churazov et al. (2001). We discuss a viscous time-scale in the accretion disk of SS433 in implication to the observed broad band power spectrum.Comment: 8 pages, 2 figures. Submitted to A&

Spectroscopy of Optical Counterparts of Ultraluminous X-ray Sources

Here we present the results of panoramic and long-slit observations of eight ULX nebular counterparts held with the 6m SAO telescope. In two ULXNe we detected for the first time signatures of high excitation ([OIII]5007 / H\beta > 5). Two of the ULXs were identified with young (T ~ 5-10 Myr) massive star clusters. Four of the eight ULX Nebulae (ULXNe) show bright high-excitation lines. This requires existence of luminous (~ 10^{38} .. 10^{40} erg/s) UV/EUV sources coinciding with the X-ray sources. Other 4 ULXNe require shock excitation of the gas with shock velocities of 20-100km/s. However, all the studied ULXN spectra show signatures of shock excitation, but even those ULXNe where the shocks are prevailing show presence of a hard ionizing source with the luminosity at least ~10^{38} erg/s. Most likely shock waves, X-ray and EUV ionization act simultaneously in all the ULXNe, but they may be roughly separated in two groups, shock-dominated and photoionization-dominated ULXNe. The ULXs have to produce strong winds and/or jets powering their nebulae with \~10^{39} erg/s. Both the wind/jet activity and the EUV source needed are consistent with the suggestion that ULXs are high-mass X-ray binaries with the supercritical accretion disks of the SS433 type.Comment: submitted to Astrophysical Bulletin (Bull. Special Astrophys. Obs.

Unravelling a simple method for the low temperature synthesis of silicon nanocrystals and monolithic nanocrystalline thin films

In this work, we present new results on the plasma processing and structure of hydrogenated polymorphous silicon (pm-Si:H) thin films. pm-Si:H thin films consist of a low volume fraction of silicon nanocrystals embedded in a silicon matrix with medium range order, and they possess this morphology as a significant contribution to their growth comes from the impact on the substrate of silicon clusters and nanocrystals synthesized in the plasma. Quadrupole mass spectrometry, ion flux measurements, and material characterization by transmission electron microscopy (TEM) and atomic force microscopy all provide insight on the contribution to the growth by silicon nanocrystals during PECVD deposition. In particular, cross-section TEM measurements show for the first time that the silicon nanocrystals are uniformly distributed across the thickness of the pm-Si:H film. Moreover, parametric studies indicate that the best pm-Si:H material is obtained at the conditions after the transition between a pristine plasma and one containing nanocrystals, namely a total gas pressure around 2 Torr and a silane to hydrogen ratio between 0.05 to 0.1. From a practical point of view these conditions also correspond to the highest deposition rate achievable for a given RF power and silane flow rate.ope

Synthesis of Thin Films of Cadmium Chalcogenides by the Plasma-Chemical Method for the Creation of Tandem Solar Cells

In this paper, we present a new method for obtaining the upper CdTe layer for cascade solar cells based on a-Si. The use of this method will make it possible to obtain cascade solar cells without destroying the lower cascade.Исследование выполнено за счет гранта Российского научного фонда (проект № 22-12-00167)