Application of the Transverse Seebeck Effect to Measurement of Instantaneous Values of a Heat Flux on a Vertical Heated Surface under Conditions of Free-Convection Heat Transfer

The design and features of application of a heat-flux sensor whose operation is based on the transverse Seebeck effect are described. The capabilities of the sensor are demonstrated using the investigation of free-convection heat transfer as an example. The results of measurement of instantaneous values of a heat flux on a heated vertical surface are given for different regimes of air flow in a free-convection boundary layer.     

A Wide Temperature-Range Measuring Unit for Registering the Parameters of Semiconductor Pulsed-Laser Emission Fields

Instruments and Experimental Techniques - The main problems of measuring the spatial distribution of the emission intensity of high-power semiconductor pulsed lasers are stated and engineering...     

Investigating the effective thermal conductivity of a vibrating bed in a vacuum

We describe the experimental installation and give the results from experimental determination of the effective thermal conductivity of a vibrating bed in a vacuum, in the horizontal direction, for various vibration parameters and for various particle sizes of the finegrained material.Translated from Inhenerno-Fizicheskii Zhurnal, Vol. 16, No. 6, pp. 1039–1044, June, 1969.     

Variations of 226Ra Concentration in Waters of the Pacific

The ²²⁶Ra content was determined in waters of the hydrological fronts located in the western part of the Pacific and in the equatorial pelagic waters of the central part of the Pacific. The ²²⁶Ra concentration averaged throughout sampling sites was 4.3 ×10-14 g/l (standard deviation 2.0 × 10-14 g/l). The average ²²⁶Ra concentration in the pelagic waters was 3.5 ×10-14 g/l (N = 37, standard devation 1.5 ×10-14 g/l) and in the waters of the equatorial sampling area, 3.9 ×10-14 g/l (N = 28, standard deviation 1.5 ×10-14 g/l). The maximal variations of ²²⁶Ra concentration (from 1.6 to 6.5 ×10-14 g/l) were found in the pelagic waters in the vicinity of the frontal hydrological zones of the equatorial front. Variations of the ²²⁶Ra concentration in the surface waters caused by ²²⁶Ra bioaccumulation can reach 0.2%. These variations reflect the zonal distribution of the primary bioproduction.     

Elastic and anelastic properties of C/Mg–2wt.%Si composite during thermal cycling

Ultrasonic technique is employed to detect microstructural changes induced in a carbon fiber–magnesium matrix composite (Mg–2wt.%Si alloy matrix reinforced by long unidirectional carbon fibers with volume fraction of about 30%) during thermal cycling in the range of 100–360 K through measurements of its elastic and anelastic properties. Variations of the elastic modulus of the composite during thermal cycling is largely determined by elasticity of the carbon fibers stressed by the thermally expanded/contracted matrix. Anelastic properties of the composite are caused by dislocation motion in the matrix.