Spectrophotometric diagnostics of energy characteristics and conductance of the auroral ionosphere from satellite: 1. Specific methods,accuracy problems,and instrumentation requirements

One of the most important tasks of space research is to find a way of real-time monitoring of the space environment conditions around the Earth. This is necessary in order to provide warning about the threats of critical failures in ground-based and space technological systems, thus providing for their stable and secure operation. In view of this concern, methods of diagnostics of ionospheric energy and electrodynamic characteristics continue to be developed on the basis of spectral and photometric measurements, analyzing the glow intensity of emissions of the upper atmosphere observed from above. Serial panoramic monochromatic maps of the intensity of luminosity of the upper atmosphere emissions measured from orbiting detectors can serve as a main data source for such an analysis. In this paper we consider the principal aspects of the method, and, on this basis, the instrumentation requirements are formulated.     

Model of effective heat conduction in polymer composite porous materials

A model and a technique for calculating polymer composite materials with an ellipsoid-shaped filler that take into account the influence of system porosity, particle anisodiametry and a boundary layer on the effective heat conduction are proposed. The results of calculations made by numerical methods are in a good agreement with the well-known statistic and Odolevskii, Maxwell, and Dul’nev matrix models.     

Exact solution of a problem on heat exchange in channels under unsteady conditions at low biot number values

A number of exact solutions of a problem on heat exchange in channels under unsteady conditions at the low Biot numbers and sufficiently low Brune numbers with and without consideration for a heat carrier stay period in a pipeline are obtained.     

Practical Fusion of Quantized Measurements via Particle Filtering

Most treatments of decentralized estimation rely on some form of track fusion, in which local track estimates and their associated covariances are communicated. This implies a great deal of communication; and it was recently proposed that by an intelligent quantization directly of measurements, the communication needs could be considerably cut. However, several issues were not discussed. The first of these is that estimation with quantized measurements requires an update with a non-Gaussian distribution, reflecting the uncertainty within the quantization "bin."; In general this would be a difficult task for dynamic estimation, but Markov-chain Monte-Carlo (MCMC, and specifically here particle filtering) techniques appear quite appropriate since the resulting system is, in essence, a nonlinear filter. The second issue is that in a realistic sensor network it is to be expected that measurements should arrive out-of-sequence. Again, a particle filter is appropriate, since the recent literature has reported particle filter modifications that accommodate nonlinear-filter updates based on new past measurements, with the need to refilter obviated. We show results that indicate a compander/particle-filter combination is a natural fit, and specifically that quite good performance is achievable with only 2-3 bits per dimension per observation. The third issue is that intelligent quantization requires that both sensor and fuser share an understanding of the quantization rule. In dynamic estimation this is a problem since both quantizer and fuser are working with only partial information; if measurements arrive out-of-sequence the problem is compounded. We therefore suggest architectures, and comment on their suitabilities for the task. A scheme based on delta-modulation appears to be promising.     

Method of equivalent transformations to control an observation satellite by means of inertial drives under uncertainty

A system of differential equations for the angular motion of an observation satellite (OS) equipped with an inertial drive electromagnetic device (EMD) without a controlling flywheel engine is presented. Apart from lag, the calculated and uncertain limited external and parametric disturbances constantly acting on the OS control system are taken into account. It is proposed that the sliding conditions be used to obtain the high-precision OS control with the specified direct indices of the transient process quality in the angular motion. A problem of equivalent system transformation is solved to safely provide the invariance of the sliding conditions to all listed disturbances with respect to the Euler angles and their first and second derivatives.     

Determination of natural frequencies and vibration modes of a constant thickness centrally secured disk

The results of experimental and numerical studies of natural frequencies and vibration modes of a centrally secured circular plate of constant thickness are presented. The studies are carried our using the interference holography and finite element methods and the results are considered as guiding lines for determining vibration characteristics of real disks.     

Structure of technological-purpose automation models by the example of a computer-aided design system of labor standards

Structures of models for computer-aided calculation of cutting conditions and time standards for the NORMA computer-aided design system of labor standards (CADS LS) are described.     

Intermittency of solar wind density fluctuations and its relation to sharp density changes

The paper presents the study of turbulent properties of the solar wind plasma, namely, the intermittency of fluctuations of the solar wind ion flux in the earlier unexplored region of comparatively high frequencies (0.01–1 Hz). Special attention is given to a comparison of intermittency for solar wind observation intervals containing sharp (shorter than 10 min) and high-amplitude (greater than 20%) changes of the ion flux to intervals without such changes. The solar wind observation intervals containing sharp changes of the flux are found to be essentially more intermittent than the intervals of quiet solar wind. Such a comparison allows one to reveal the fundamental difference in turbulent properties of the solar wind depending on the presence or absence of sharp boundaries in plasma structures.     

From Titan’s tholins to Titan’s aerosols: Isotopic study and chemical evolution at Titan’s surface

In the present work, we focused on the possible isotopic fractionation of carbon during the processes involved in the formation of Titan’s tholins. We present the first results obtained on the ¹²C/¹³C isotopic ratios measured on Titan’s tholins synthesized in laboratory with cold plasma discharges. Measurements of isotopic ratio ¹²C/¹³C, done both on tholins and on the initial gas mixture (N₂:CH₄ (98:2)) used to produce them, do not show any evident deficit or enrichment in ¹³C relatively to ¹²C in the synthesized tholins, compared to the initial gas mixture. This observation allows to go further in the analyses of the ACP experiment data, including part of the Cassini–Huygens mission.     

Influence of ultrasonic machining on physico-mechanical properties of adhesive joints and epoxide compounds

The results of experimental studies concerning the physico-mechanical properties of adhesive joints and epoxide compound-based coatings after ultrasonic machining are presented. Also considered is a change of adhesive strength and residual stresses in different “metal — polymer” systems.