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The problem associated with the lack of multiphase flowmeters (instruments for inline measurement of the flow rates of extracted gas–condensate well products component-wise) is considered. The paper described the actual problems solved by using the multiphase flowmeters along with the main requirement to such instruments (e.g., measuring gas–condensate flow components without separation into gas and liquid phases by a separator). A method is proposed for determining volumetric contents of the components of extracted products of the gas/oil and gas–condensate wells using a nonseparation component detection technique. Sounding a gas–liquid flow with decimeter radio waves as it passes through a microwave resonator is described and a design option of a non-separation analyzer of volumetric fractions of gas, condensate, and water in the extracted products of gas–condensate wells is proposed. The volumetric fractions of gas, water, and condensate were determined based on the results of measurements of the frequency shift and the quality factor of the resonator. Moreover, an acceptable error (less than 5%) is obtained only when determining the amount of condensate at high gas/condensate ratios (300–1.000 cm3/m3) and low gas/water ratios (30–100 cm3/m3). With an increase in the water fraction or a decrease in the condensate fraction, the error of determining the gas/condensate ratio becomes unacceptably high (more than 10%). It was shown that such error can be reduced by introducing a bypass line into the flowmeter, containing a liquid-phase separation filter and a reference cavity (resonator). The reference resonator detects the frequency shift caused by the gas phase. The filter is sounded with an eight-millimeter radio beam, which only responds to the presence of water component. The data obtained from the resonator and the filter significantly expand the range of detectable gas/condensate and gas/water ratios. The proposed technical solutions realized in the multiphase flowmeters for gas–condensate fields make it possible to determine the volumetric fractions of the components of extracted products of gas–condensate wells, and control the performance quality of the separators that separate out liquid before subsequent supply of gas (when the equipment is installed upstream and downstream of the separator). Large flow cross-section resonators could be used to monitor gas–liquid flow passing through the large-diameter pipelines, such as trunk pipelines. [ABSTRACT FROM AUTHOR]

The results of the long-term gradient magnetic measurements performed in the southwest part of Baikal as supplementing the experiment on deep-water monitoring of the electric field vertical component, can be applied to study the deep geoelectric section. Baikal cannot be approximated by a two-dimensional model in the region under study. Therefore, a three-dimensional geoelectric model of the lake and adjacent territories was constructed based on the existing geological and geophysical data. However, these data are insufficient for the region where our observations are carried out. Refinement of the section upper part based on the magnetic field gradients on long bases has been performed using the neural network inversion method. Then, proceeding from the obtained basic model, alternative models were developed, which reflect the known hypotheses about the structure of the deep part of the Baikal rift section: mantle diapir and asthenospheric upwelling. The phase differences between the base-averaged field gradient and the field itself at the base site, as well as the phase differences on the ends of this base, as the most noise-proof gradient functions, are calculated for them. Based on comparison of the experimental and model frequency curves, it is concluded that the mantle diapir model fits best the experimental data, at least, in the southwest part of the Baikal rift zone. [ABSTRACT FROM AUTHOR]

Abstract: Recent progress in chromium and iron doped II–VI semiconductor materials makes them the laser sources of choice when one needs a compact system with broad mid-IR tunability over 1.9–6μm. Output powers exceeding 10W, output energies 20mJ, pulse durations 80fs, peak powers in excess of 1GW, and efficiency up to 70% were demonstrated in several Cr doped semiconductors. The unique combination of technological and spectroscopic characteristics makes these materials ideal candidates for mid-IR tunable and ultrafast laser systems. This article reviews transition metal doped II–VI materials and recent progress in Cr- and Fe- doped solid-state mid-IR lasers. [Copyright &y& Elsevier]

Abstract: In this work we report the study of Cr2+:ZnSe photo-luminescence under UV and visible excitation as well as middle-infrared electroluminescence of n-type, Cr doped bulk ZnSe crystals. Photo-conductance studies were performed to verify (2+)→(1+)→(2+)* ionization transitions responsible for Cr2+ excitation. We report the first to our knowledge, Cr2+:ZnSe lasing using 532nm excitation. The first ever room temperature electroluminescence was also achieved in bulk n-type Cr:Al:ZnSe. This electroluminescence over 1800–2800nm spectral range is in a good agreement with the mid-IR Cr2+ fluorescence under intra-shell optical excitation. Other spectral bands of electroluminescence were also observed at 600nm and 8μm. The visible electroluminescence observed is attributed to Vzn–Al complexes in conductive crystals. The nature of the 8μm electroluminescence requires additional studies. Photo-ionization results are essential for optical pumping of Cr:ZnSe by easily available visible lasers, and, most importantly, both these and the electroluminescence results open a pathway for Cr:ZnSe broadband mid-IR lasing under direct injection of free carriers. Future directions for electrical excitation of low dimensional II–VI structures, where quantum confinement of the atomic impurity is used, could result in a much more efficient transfer of energy from the host to the localized impurity, are discussed. [Copyright &y& Elsevier]

Materials based on a rubber-epoxy matrix filled with coal-tar pitch and petroleum coking additive were investigated. The effect of the fillers on the degradation rate of the cured material and the coke residue yield was studied using data of thermogravimetric and differential thermal analyses and differential scanning calorimetry, It was established that the introduction of coal-tar pitches lowers the thermooxidative stability of the polymer matrix, while the introduction of petroleum coking additive raises it. In tests under isothermal and dynamic conditions, the greatest amount of coke residue is formed after annealing of the composite with petroleum coking additive. Burnout of the coke residue of the given material occurs in the widest temperature range. The influence of the nature of the filler and the test temperature on the mechanical properties of the materials was investigated. It was established that at elevated temperature the best deformation and strength properties are possessed by material with the petroleum coking additive. The prospects of using the obtained materials as heat-shielding coatings were assessed. ] [ABSTRACT FROM AUTHOR]