Characteristics of a Cup Anemometer and a Procedure of Measuring the Wind Velocity

On the basis of the data of laboratory, model, and field investigation of the characteristics of a proposed cup anemometer, we obtain the following results: the distance constant is equal to 0.32 m with a mean-square deviation of 0.05 m, which is smaller than for the other anemometers of this type by an order of magnitude, the dynamic characteristics of the anemometer are linear for typical conditions of atmospheric turbulence, the variance and spectrum of noises (as a result of transformation of pulsed signals at the output of the anemometer) are described by universal functions with known parameters, the transmission bandwidth is approximately equal to 2 Hz for wind velocities lower than 5 m/sec and up to 5 Hz for higher wind velocities, and the errors of measurements of the mean wind velocity and the characteristics of the longitudinal component of velocity are approximately equal to 1 and 3%, respectively. The dimensions and weight of the anemometer are quite small, which enables one to perform long-term measurements of the characteristics of wind velocity for all types of platforms within broad ranges of hydrometeorological conditions.     

Comparing satellite and meteorological data on wind velocity over the Black Sea

Wind-velocity data obtained from in situ measurements at the Golitsyno-4 marine stationary platform have been compared with QuikSCAT scatterometer data; NCEP, MERRA, and ERA-Interim global reanalyses and MM5 regional atmospheric reanalysis. In order to adjust wind velocity measured at a height of 37 m above the sea surface to a standard height of 10 m with stratification taken into account, the Monin–Obukhov theory and regional atmospheric reanalysis data are used. Data obtained with the QuikSCAT scatterometer most adequately describe the real variability of wind over the Black Sea. Errors in reanalysis data are not high either: the regression coefficient varies from 0.98 to 1.06, the rms deviation of the velocity amplitude varies from 1.90 to 2.24 m/s, and the rms deviation of the direction angle varies from 26° to 36°. Errors in determining the velocity and direction of wind depend on its amplitude: under weak winds (<3 m/s), the velocity of wind is overestimated and errors significantly increase in determining its direction; under strong winds (>12 m/s), its velocity is underestimated. The influence of these errors on both spatial and temporal estimates of the characteristics of wind over the Black Sea is briefly considered.     

Mössbauer studies of structural features in tourmaline of various genesis

Nuclear gamma ray (Mössbauer) spectroscopy (ngr) was used to examine 114 samples of tourmaline from different deposits. The absorption curve shape of the ngr spectra was found to depend not only on tourmaline composition, but also on the character of cation distribution in the crystal structure. The complex superpositional nature of the spectra corresponds to a statistical distribution of iron ions, whereas a minimum number of doublets is observed in an ordered distribution of these ions in the structure. The existence of nonequivalent Fe sites with statistical cation distribution in Y and Z positions was confirmed by experiments on iron oxidation in tourmaline, temperature studies of quadrupole splitting, and probability analysis of formation of nonequivalent sites in accordance with the tourmaline structure. We established experimentally that iron ions in Y positions have a lower ionization potential than in Z positions. The coefficient of iron oxidation in tourmaline, the occupancy of crystallographic positions, and the nature of cation distribution in the structure are features permitting identification of the particular genetic type to which the test sample belongs.     

Location, valence states, and oxidation mechanisms of iron in eudialyte-group minerals from Mössbauer spectroscopy

A representative collection of structurally characterized eudialyte-group minerals (EGM) with varying relative concentrations of Fe²⁺ and Fe³⁺ ions from several localities was investigated at room temperature by ⁵⁷Fe Mössbauer spectroscopy coupled with magnetometric, optical, and X-ray powder diffraction methods. To refine the Mössbauer parameters of isomer shift and quadrupole splitting for Fe²⁺ and Fe³⁺ in different types of coordination polyhedra (planar quadrangle, square pyramid, and distorted octahedron) in EGM structures, we also collected Mössbauer parameters for gillespite and labuntsovite. The main purpose of this work is to determine the location of Fe³⁺ in different sites in typical eudialyte, rastsvetaevite, georgbarsanovite, and some of their naturally hydrated and heat-treated analogs, and investigate the kinetics and oxidation mechanisms of iron ions in their structures. Our study has confirmed the presence of Fe²⁺ ions in the planar quadrangle and square pyramid in primary eudialytes, as well as the presence of Fe³⁺ ions in the square pyramid and distorted octahedron in primary, naturally hydrated, and heat-treated eudialytes. According to this study, hydrated eudialytes are characterized by the location of Fe³⁺ ions mainly in octahedra with OH groups and/or water molecules at trans vertices, while heat-treated eudialytes are characterized by their location in square pyramids with an O^2? anion at the apical vertex.