Characterization and Modeling of Advanced Modified Surfaces.

A promising approach to surface modification involves diamondlike carbon (DLC) coatings with functionally-graded surfaces (FGS) as substrates. Titanium nitride substrates have a great potential as a FGS for the DLC coating, since titanium and titanium alloy surfaces processed by enhanced glow discharge nitriding develop a nitrogen concentration profile that results in gradual increase in the material hardness in the surface region. An investigation of the atomic structure of DLC films and the surface layer structure produced in the enhanced glow discharge nitriding was conducted in the course of this work. DLC and Si-DLC films were found to be mainly amorphous, dense and of high hardness, with featureless and very smooth surfaces. For the DLC films, the sp\rm\sp3/sp\sp2 ratio varied between 3.2 and 4.1. A microstructure that can be described as small graphitelike clusters interconnected by a network of sp\sp3-bonded carbon was suggested for these films. Characterization of the Si-DLC films revealed a wide variation in the \rm sp\sp3/sp\sp2 ratio, between 1.5 and 5.4. The effect of Si atoms incorporated in the DLC structure seems to be the prevention of aromatic clustering and promotion of the formation of sp\sp3 bonds. A structural model consisting of a mixed \rm sp\sp2-sp\sp3 carbon network with the C(sp\sp2) atoms present in olefinic rather than aromatic form was suggested. X-ray absorption examination of the nitrided surfaces demonstrated an increase of the nearest-neighbor N coordination numbers and higher phase fractions of $\delta$-TiN as the particle energy and current density were increased. Processing conditions corresponding to the energies of the bombarding particles around 1 keV resulted in relatively thick and continuous TiN layers with a structure virtually identical to that of the TiN standard. A two-phase model of the outer layer, describing the structure as a mixture of $\delta$-TiN and $\alpha$-Ti, was proposed. This model was found to be in excellent agreement with experimental data for samples processed at the particle energies of approximately 1 keV and above. The present results clearly show that the bombarding flux energy plays the key role in the formation of the outer layer structure and thus, the migration of nitrogen into the substrate

TECHNOLOGIA OPC JAKO NARZĘDZIE INTEGRACJI SYSTEMÓW ZAUTOMATYZOWANYCH

The paper features the application of the OPC technology in automated systems. It gives an insight into the considered technology and provides the prospects of the OPC technology development.W artykule rozpatrzono możliwość zastosowania technologii OPC w systemach zautomatyzowanych. Dokonano przeglądu tej technologii, a także określono perspektywy jej rozwoju

Observations of giant outbursts from Cygnus X-1

We present interplanetary network localization, spectral, and time history information for 7 episodes of exceptionally intense gamma-ray emission from Cygnus X-1. The outbursts occurred between 1995 and 2003, with durations up to \~28000 seconds. The observed 15 - 300 keV peak fluxes and fluences reached 3E-7 erg /cm2 s, and 8E-4 erg / cm2 respectively. By combining the triangulations of these outbursts we derive an ~1700 square arcminute (3 sigma) error ellipse which contains Cygnus X-1 and no other known high energy sources. The outbursts reported here occurred both when Cyg X-1 was in the hard state as well as in the soft one, and at various orbital phases. The spectral data indicate that these outbursts display the same parameters as those of the underlying hard and soft states, suggesting that they represent another manifestation of these states.Comment: 27 pages, 9 figures. Revised version. Accepted for publication in the Astrophysical Journal, tentatively scheduled for October 20, 2003 Part

Fast spectral variability of GRBs with known redshifts

The fast spectral variability of gamma-ray bursts (GRBs) with known redshifts is investigated using the Konus-Wind experiment data in time scale up to 2ms. Tracks of these GRBs in the luminosity-peak energy plane (Liso,EP ) in the rest-frame are obtained. The distribution of maximum values of an instantaneous luminosity in the GRB’s rest frame Liso is derived for such GRBs depending on the peak energy EP

Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind

We have performed a joint analysis of prompt emission from four bright short gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments. This joint analysis allows us to investigate the spectral properties of short-duration bursts over a wider energy band with a higher accuracy. We find that these bursts have a high E$_{\rm peak}$, around 1 MeV and have a harder power-law component than that of long GRBs. However, we can not determine whether these spectra follow the cut-off power-law model or the Band model. We also investigated the spectral lag, hardness ratio, inferred isotropic radiation energy and existence of a soft emission hump, in order to classify them into short or long GRBs using several criteria, in addition to the burst duration. We find that all criteria, except for the existence of the soft hump, support the fact that our four GRB samples are correctly classified as belonging to the short class. In addition, our broad-band analysis revealed that there is no evidence of GRBs with a very large hardness ratio, as seen in the BATSE short GRB sample, and that the spectral lag of our four short GRBs is consistent with zero, even in the MeV energy band, unlike long GRBs. Although our short GRB samples are still limited, these results suggest that the spectral hardness of short GRBs might not differ significantly from that of long GRBs, and also that the spectral lag at high energies could be a strong criterion for burst classification.Comment: 23 pages, 6 figures, accepted for Publications of the Astronomical Society of Japa

Method for Osteosynthesis of Long Tubular Bones Using a Distraction-Reposition Apparatus of External Fixation

Over the past decades, the problem of treating multiple fractures of the limb bones has been the focus of attention of most orthopedic traumatologists in our country and abroad. The urgency of the problem is also determined by the fact that the nature of injuries and their consequences changes with a tendency to increase. Qualitative changes in the structure of injuries are due to an increase in the level of multiple and associated injuries. The use of sequential osteosynthesis in patients with fractures of the long tubular bones of the extremities implies primary stabilization of bone fragments with an externalfixation device and repeated immersion osteosynthesis, when it is possible to achieve stabilization of the patient's condition. There are various rod and pin devices for fixation, some of them are for fixing (which are necessary to remove before the operation), some for preliminary reposition of the fracture during the operation (necessary to remove the skeletal traction or plaster cast and apply the apparatus, which only adds steps to the procedure). The proposed technique is notable for its simple assembly and application, as well as its ease of construction, which ensures patient mobility and allows the patient to stabilize without imperfections and perform final immersion osteosynthesis