Continuous-wave operation of singlemode GaInAsSb lasers emittingnear 2.2 μm at Peltier temperatures

A continuous-wave regime, lasing near 2.2 μm, has been achieved for single longitudinal mode GaInAsSb double heterostructure lasers mounted on a Peltier cooler. In the pulsed regime the lasers exhibited a characteristic temperature of the threshold current as high as 132 K at heatsink temperatures up to 60°C     

Industrial applications of heat transfer enhancement: The modern state of the problem (a Review)

Methods used for enhancing heat transfer in power installations and industrial thermal engineering apparatuses are reviewed. Classification of these methods is given, and the corresponding types of intensifiers are considered.     

Errors in determining coal quality

Errors in determining coal quality are compared. For the example of the ash content, it is shown that the error in forming the samples is almost an order of magnitude greater than the error in sample analysis. The metrological characteristics and conditions of correct utilization of results from coal analysis are considered in the light of GOST R ISO 5725 standards. The correct comparison of results obtained by different methods is described.     

Stability of Plane-Parallel Pulsational Flow of Two Miscible Fluids under High Frequency Horizontal Vibrations

Linear stability of plane-parallel pulsational flow of two miscible fluids in a horizontal layer subjected to high frequency horizontal vibrations is investigated neglecting viscosity and diffusion. Long-wave instability is studied analytically and instability to the perturbations with finite wavelength—numerically.     

Effect of thermal annealing on the properties of borophosphate systems containing simulated Cs + Sr radioactive waste fractions

The effect of thermal annealing on the resistance of borophosphate systems to crystallization and the effect of crystallization on the hydrolytic stability of the materials were examined. Systems containing simulated Cs + Sr fraction were studied. Annealing at 400–500°C leads to a noticeable decrease in the leach rate. Annealing at a higher temperature, 600°C, leads to crystallization of the glass and to a considerable increase in the leach rate.     

Limiting parameters of high-power single-stripe laser diodes in the range of 800–808 nm in the pulsed mode

Experimental results on the study of the output parameters of high-power continuous-wave (cw) laser diodes operating in the pulsed mode and the results of numerical simulation of the total efficiency of laser diodes with cavity lengths of 3 and 4 mm in a wide range of pump currents are presented. The spectral parameters of the high-power laser diodes are studied at various pulse-repetition rates. The possible causes of the limited output power in the pulsed mode are discussed.     

Visualization of the Centre of Projection Geometrical Locus in a Single Image

Single view reconstruction (SVR) is an important approach for 3D shape recovery since many non‐existing buildings and scenes are captured in a single image. Historical photographs are often the most precise source for virtual reconstruction of a damaged cultural heritage. In semi‐automated techniques, that are mainly used under practical situations, the user is the one who recognizes and selects constraints to be used. Hence, the veridicality and the accuracy of the final model partially rely on man‐based decisions. We noticed that users, especially non‐expert users such as cultural heritage professionals, usually do not fully understand the SVR process, which is why they have trouble in decision making while modelling. That often fundamentally affects the quality of the final 3D models. Considering the importance of human performance in SVR approaches, in this paper we offer a solution that can be used to reduce the amount of user errors. Specifically, we address the problem of locating the centre of projection (CP). We introduce a tool set for 3D visualization of the CP's geometrical loci that provides the user with a clear idea of how the CP's location is determined. Thanks to this type of visualization, the user becomes aware of the following: (1) the constraint relevant for CP location, (2) the image suitable for SVR, (3) more constraints for CP location required, (4) which constraints should be used for the best match, (5) will additional constraints create a useful redundancy. In order to test our approach and the assumptions it relies on, we compared the amount of user made errors in the standard approaches with the one in which additional visualization is provided.     

Rapid determination of zinc in soils by laser-induced breakdown spectroscopy

The possibility of quantitative detection of trace zinc levels in soils per single laser pulse using laser-induced breakdown spectroscopy is shown. The development of laser plasma and the signal-to-noise ratio are studied when evaporating soils by the second (532 nm) and the third (355 nm) harmonics of an Nd:YAG pulse laser. The use of the third harmonics permits one to reach the zinc detection limit (18 ppm) below Occupational Exposure Limits (OEL) in soil (150 ppm) and below the mean abundance in the earth’s crust of zinc (83 ppm). This allows the use of the suggested technique for the rapid determination of soil pollution with zinc and searching for geochemical anomalies.