New Precision Orbits of Bright Double-Lined Spectroscopic Binaries. I: RR Lyncis, 12 Bootis, and HR 6169

Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coude' feed telescope at KPNO provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8IV), and HR 6169 (A2V). We derive orbital dimensions and minimum masses with accuracies of 0.06 to 0.9 %. The three systems, which have V magnitudes of 5.54, 4.83, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the prospect, when our spectroscopic observations are complemented by interferometric observations, of fully-determined orbits, precise masses, and distances. In the case of RR Lyn, which is also a detached eclipsing binary with a well-determined orbital inclination, we are able to determine the semimajor axis of the relative orbit, a = 29.32 +/- 0.04 Rsun, primary and secondary radii of 2.57 +/- 0.02 Rsun and 1.59 +/- 0.03 Rsun, respectively; and primary and secondary masses of 1.927 +/- 0.008 Msun and 1.507 +/- 0.004 Msun, respectively. Comparison of our new systemic velocity determination, gamma = -12.03 +/- 0.04 km/s, with an earlier one, gamma = -11.61 +/- 0.30 km/s, shows no evidence of any change in the systemic velocity in the 40 years separating the two measurements, a null result that neither confirms nor contradicts the presence of the low-mass third component proposed by Khaliullin & Khaliullina (2002). Our spectroscopic orbit of 12 Boo is more precise that that of Boden et al. (2005), but confirms their results about this system. Our analysis of HR 6169 has produced a major improvement in its orbital elements. The minimum masses of the primary and secondary are 2.20 +/- 0.01 and 1.64 +/- 0.02 Msun, respectively.Comment: To appear in the May A

Properties of the δ\delta Scorpii Circumstellar Disk from Continuum Modeling

We present optical $WBVR$ and infrared $JHKL$ photometric observations of the Be binary system $\delta$ Sco, obtained in 2000--2005, mid-infrared (10 and $18 \mu$m) photometry and optical ($\lambda\lambda$ 3200--10500 \AA) spectropolarimetry obtained in 2001. Our optical photometry confirms the results of much more frequent visual monitoring of $\delta$ Sco. In 2005, we detected a significant decrease in the object's brightness, both in optical and near-infrared brightness, which is associated with a continuous rise in the hydrogen line strenghts. We discuss possible causes for this phenomenon, which is difficult to explain in view of current models of Be star disks. The 2001 spectral energy distribution and polarization are succesfully modeled with a three-dimensional non-LTE Monte Carlo code which produces a self-consistent determination of the hydrogen level populations, electron temperature, and gas density for hot star disks. Our disk model is hydrostatically supported in the vertical direction and radially controlled by viscosity. Such a disk model has, essentially, only two free parameters, viz., the equatorial mass loss rate and the disk outer radius. We find that the primary companion is surrounded by a small (7 $R_\star$), geometrically-thin disk, which is highly non-isothermal and fully ionized. Our model requires an average equatorial mass loss rate of 1.5\times 10^{-9} M_{\sun} yr$^{-1}$.Comment: 27 pages, 9 figures, submitted to Ap

Advanced engines for non-conventional kinematic chains in agriculture

To intensify agricultural production in the market environment, it is necessary to reconstruct the whole economic mechanism considering energy efficiency. This calls for the search of new ideas for alternative designs and engine types that can raise the performance of heat engines to a new level while keeping their use in vehicles, machinery, and small energy facilities feasible. One of the options is the displaced shaft rotary engine. This article analyses the kinematic and dynamic metrics of the engines of this type and presents the calculations of these metrics for the prototype. Key advantages and disadvantages of this type of engine in terms of working process dynamics are set out. It is also compared to the reciprocal internal combustion engine of the same structural dimensions

Results of engineless studies of power plant supports for machine-tractor units operation

When using a machine-tractor unit, external conditions of its operation change in a wide range. It results in frequent changes in the parameters of speed and load modes of its power plant. Resulting vibrations and oscillations in addition to discomfort and excessive loads on components and mechanisms of the power plant also cause fuel overspending and power losses. To reduce negative vibration impact on effective performance of the power plant creation of supports with adjustable characteristics is suggested. Both internal unbalance of the power plant itself and external influence of variable moment of resistance and impulses of supports themselves are considered perturbing moments. Changes in rigidity and damping coefficients of relevant supports can reduce the amplitude of oscillations of the power plant in variable operating modes, which will improve its utilization indicators

The off-label use of drugs for parenteral nutrition as a solvent of substances slightly soluble in water in pharmacological research

Because of the problem to evaluate biological activity in water-soluble substances in all phases of preclinical and clinical studies, the research work enabled to develop the original solvent for poorly soluble compounds based on substances for parenteral nutrition. The main aim is to examine the impact of the original solvent based on substances for parenteral nutrition on biological systems exemplified by the hemostatic system, characterized by sensitivity and variability of the effects in response to any impact, and its comparison with the solvents that are conventional in pharmacological research. Experimental work is performed according to the “guidance on preclinical research of new pharmacological substances” in vitro. The findings show that traditional solvents at low dosages affect all the researched indicators of the hemostasis system. The smallest effect in respect of the hemostatic system was characterized by ethanol, and the most apparent antiaggregational effect was registered with dioxane. 10% concentration of original blend of lipids made no effect on hemostasis system. Thus, according to their own findings and experience in application of lipid emulsions as substances of parenteral nutrition, they can be considered to be an adequate solvent in all phases of preclinical and clinical studies of new drugs