Determining the parameters of Weibull function to estimate the wind power potential in conditions of limited source meteorological data

We studied the information basis for the assessment of wind power potential on the territory of Russia. We described the methodology to determine the parameters of the Weibull function, which reflects the density of distribution of probabilities of wind flow speeds at a defined basic height above the surface of the earth using the available data on the average speed at this height and its repetition by gradations. The application of the least square method for determining these parameters, unlike the use of graphical methods, allows performing a statistical assessment of the results of approximation of empirical histograms by the Weibull formula. On the basis of the computer-aided analysis of the statistical data, it was shown that, at a fixed point where the wind speed changes at different heights, the range of parameter variation of the Weibull distribution curve is relatively small, the sensitivity of the function to parameter changes is quite low, and the influence of changes on the shape of speed distribution curves is negligible. Taking this into consideration, we proposed and mathematically verified the methodology of determining the speed parameters of the Weibull function at other heights using the parameter computations for this function at a basic height, which is known or defined by the average speed of wind flow, or the roughness coefficient of the geological substrate. We gave examples of practical application of the suggested methodology in the development of the Atlas of Renewable Energy Resources in Russia in conditions of deficiency of source meteorological data. The proposed methodology, to some extent, may solve the problem related to the lack of information on the vertical profile of repeatability of the wind flow speeds in the presence of a wide assortment of wind turbines with different ranges of wind-wheel axis heights and various performance characteristics in the global market; as a result, this methodology can become a powerful tool for effective selection of equipment in the process of designing a power supply system in a certain location.     

Functional material based on polyvinylalcohol hydrogel for absorption spectrophotometry

A new functional composite material based on polyvinylalcohol hydrogel cross-linked by silica with metal-sensitive properties was proposed. The metal-sensitive properties of the functional material were provided through inclusion in the gel of the organic analytical reagent HOCAC. The isoelectric point of the PVA-based gel hardened by silicic acid was found and enabled the reason for the good retention of the used organic reagents in the gel phase in strongly acidic solution to be explained. The optimum technology for preparing sensitive layers (SLs) that provided high sensitivity and satisfactory kinetics for the spectroscopic response of the SLs was proposed based on the spectrophotometric and morphological studies. This enabled the proposed composite material to be used for quantitative analysis. The possible use of the composite film material based on the organic analytical reagent HOCAC for quantitative determination of Pb(II) ions was demonstrated.     

An experimental study of the degradation of particles in complex plasma

Changes of melamine–formaldehyde resin (MF-R) particles occurring in complex dusty plasma have been investigated. Using a specially developed method, plasma-modified MF-R particles have been extracted from a dust trap after levitation for various periods of time and studied by electron microscopy techniques. Changes in the surface structure of MF-R particles are determined, and quantitative data on the variation in particle dimensions depending on the time of occurrence in plasma are obtained.