Equation of state SAHA-S meets stellar evolution code CESAM2k

We present an example of an interpolation code of the SAHA-S equation of state that has been adapted for use in the stellar evolution code CESAM2k. The aim is to provide the necessary data and numerical procedures for its implementation in a stellar code. A technical problem is the discrepancy between the sets of thermodynamic quantities provided by the SAHA-S equation of state and those necessary in the CESAM2k computations. Moreover, the independent variables in a practical equation of state (like SAHA-S) are temperature and density, whereas for modelling calculations the variables temperature and pressure are preferable. Specifically for the CESAM2k code, some additional quantities and their derivatives must be provided. To provide the bridge between the equation of state and stellar modelling, we prepare auxiliary tables of the quantities that are demanded in CESAM2k. Then we use cubic spline interpolation to provide both smoothness and a good approximation of the necessary derivatives. Using the B-form of spline representation provides us with an efficient algorithm for three-dimensional interpolation. The table of B-spline coefficients provided can be directly used during stellar model calculations together with the module of cubic spline interpolation. This implementation of the SAHA-S equation of state in the CESAM2k stellar structure and evolution code has been tested on a solar model evolved to the present. A comparison with other equations of state is briefly discussed. The choice of a regular net of mesh points for specific primary quantities in the SAHA-S equation of state, together with accurate and consistently smooth tabulated values, provides an effective algorithm of interpolation in modelling calculations. The proposed module of interpolation procedures can be easily adopted in other evolution codes.Comment: 8 pages, 5 figure

Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets

The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment

СОВРЕМЕННОЕ СОСТОЯНИЕ И ПРОБЛЕМы ОБОГАЩЕНИЯ ТИТАНОЦИРКОНИЕВОГО СыРЬЯ В УКРАИНЕ

В природе известно 70 минералов, в различных количествах содержащих титан. На сегодняшний день промышленными источниками титанового сырья являются месторождения, содержащие ильменит, рутил, лейкоксен и, в послед-нее время, анатаз. Львиная (около 90%) часть ильменитовых, лейкоксеновых и рутиловых концентратов используются для производства диоксида титана. Из ильменитовых концентратов получают синтетический рутил и титановые шла-ки, которые можно использовать как для производства губчатого титана, так и диоксида титана. На производство металлического титана используется 7-10% сырья. Природный рутил, кроме того, используется частично и для обмазки сварочных электродов. Наиболее богатыми по содержанию диоксида титана являются рутиловые концентраты (93-96%), ильменитовые содержат 44-70% диоксида титана, а концентраты из лейкоксеновых руд содержат до 90% TiO

The Role of Birds as Potential Reservoirs of West Nile Virus in the Territory of the Russian Federation

Submitted are the materials on epizootiology of West Nile Fever in birds, taking into account their migration. Described are the characteristics of WNF in wild and synanthropic birds. Ecological relationships between birds, mosquitoes, ticks and West Nile virus are analyzed. Main autumn bird migratory directions are characterized and the data on WNF monitoring in birds in different geographical regions of Russia are presented

Electroproduction, photoproduction, and inverse electroproduction of pions in the first resonance region

Methods are set forth for determining the hadron electromagnetic structure in the sub-$N\bar{N}$-threshold timelike region of the virtual-photon ``mass'' and for investigating the nucleon weak structure in the spacelike region from experimental data on the process $\pi N\to e^+e^- N$ at low energies. These methods are formulated using the unified description of photoproduction, electroproduction, and inverse electroproduction of pions in the first resonance region in the framework of the dispersion-relation model and on the basis of the model-independent properties of inverse electroproduction. Applications of these methods are also shown.Comment: The revised published version; Revtex4, 18 pages, 6 figure

Longitudinal Momentum Fraction X_L for Two High P_t Protons in pp->ppX Reaction

We present an analysis of new data from Experiment E850 at BNL. We have characterized the inclusive cross section near the endpoint for pp exclusive scattering in Hydrogen and in Carbon with incident beam energy of 6 GeV. We select events with a pair of back-to-back hadrons at large transverse momentum. These cross sections are parameterized with a form $\frac{d \sigma}{d X_{L}}$ $\sim(1-X_{L})^{p}$, where ${X_{L}}$ is the ratio of the longitudinal momentum of the observed pair to the total incident beam momentum. Small value of $p$ may suggest that the number of partons participating in the reaction is large and reaction has a strong dependence on the center-of-mass energy. We also discuss nuclear effects observed in our kinematic region.Comment: 4 pages, 2 figures, to be published in Proceedings of CIPANP2000, Quebec, May 22-28, 2000, requires aipproc.sty(included