Rapid method for evaluating the efficiency of excitation energy transfer between ytterbium and erbium ions in an active fiber preform

A rapid method is proposed to evaluate the efficiency of excitation energy transfer between ytterbium and erbium ions from measured relative luminescence intensity in different spectral regions in an active fiber preform, taking into account the concentration of active ions and their spectroscopic constants.     

Use of technogenic and natural solutions in hydrometallurgical operations

Conclusions  The results obtained here demonstrate the promise of using technogenic and concentrated condensates of hightemperature heat carriers to perform leaching as part of the processing of copper-nickel ores. The productive solutions that were obtained have high contents of the useful components (grams and tens of grams per liter) and could be converted to the desired end products by proven methods [12]. The following problems should be addressed first in future research in this area:

Socially desirable response tendency as a correlate of accuracy of self-reported HIV serostatus for HIV seropositive injection drug users

PURPOSE: To compare field measures of average daily energy expenditure (ADEE) against criterion data by the doubly labeled water method (DLW) in overweight women. METHODS: The subject were 20 overweight (BMI 29.9 +a- 3.0 kg.m-2) premenopausal women. Energy expenditure was measured by DLW and by the factorial method (activity diary, two techniques differing by method to obtain resting energy expenditure, REE), heart-rate monitoring (HR, two techniques differing by the FLEX-point to discriminate sedentary and activity HR), accelerometer, and pedometer. RESULTS: The ADEE(DLW) was 10.26 +a- 1.1 MJ.d-1. The mean bias (ADEE by the alternative minus ADEE(DLW) was smallest for the accelerometer (+ 0.08 +a- 1.63 MJ) and HR-FLEX10 (+ 0.11 +a- 1.67 MJ). The HR-FLEX(0) technique (lower FLEX-point) overestimated ADEE by + 1.18 (+a- 1.97 MJ). However, the random error (SD of bias) was smaller for both factorial techniques (REE measured: -0.48 +2- 0.81 MJ; REE calculated from the WHO equation: -0.22 +2- 0.88 MJ). CONCLUSION: The results show that simple factorial methods may assess ADEE with small random errors in population with a rather narrow range of physical activity. The accelerometer and HR with the higher FLEX-point have comparable results with smaller bias but larger random error compared with the factorial techniques.     

Motion of and mass transfer into a liquid droplet in the swirling flow of the geothermal medium

Based on the set of equations of the motion of and mass transfer into a single liquid droplet in a gas flow, a model was proposed that describes the behavior of the dispersed phase of the condensate of the geothermal heat-transfer medium in a cyclone apparatus. The motion of and the mass transfer into droplets in the swirling flow were studied in relation to the inhomogeneous flow pattern, the growth of droplets in the supersaturated medium, and their deformation and breakup. An analytical formula for the collecting power of a cyclone was derived, and recommendations for optimizing the apparatus parameters were made.     

Heat Exchange under Beneficiation by Condensation Methods

The all-inclusive use of the resources of geothermal heat-carriers needs the devices with active hydrodynamic regimes and optimal design parameters. The complex investigations into the heat exchange under steam condensation are conducted on models with different structures of flows in working volumes. The heat exchange coefficients depending on the regime parameters are obtained, and the basic procedures to calculate processing equipment are developed. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 99–105, May–June, 2005.     

Thermochemical methods of treatment of low-grade phosphatic raw materials

Conclusions Thermochemical synthesis offers possibility of getting effective compound fertilizers from low-grade poorly enrichable mineral raw materials. Agricultural field tests demonstrated that the compound fertilizers developed are much more effective than equivalent doses of the starting components equalized in terms of nitrogen and potassium. Consequently, apatite-based compound fertilizers can be used to radically improve soil fertility (phosphoritization with simultaneous improvement of the nitrogen-potassium regime). Research Center of the Far Eastern Branch of the Russian Academy of Sciences, Petropavovsk-Kamchatskii. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, Vol. 34, No. 1, pp. 118–122, January–February 1998.     

Dressing of Nonmagnetic Dispersed Mixtures by Electromagnetic Methods

Complex investigations into electrodynamic effect on dia- and paramagnets are conducted. Experimental device for dressing of compound dispersed mixtures with particles of nonmagnetic metals is considered. The outlook is shown for electrodynamic dressing.     

Investigation of the Stressed State and Edge Effects in a Three-Layer Cylinder

We study an axisymmetric problem of determination of the zones of stress concentration in a three-layer circular cylinder with isotropic layers. The cylinder is subjected to uniform axial loading. An approximate solution of the problem of the linear theory of elasticity is obtained by the net method. We present a solution of this sort as an example and analyze the results.     

Theory of random motion of particles in a suspension

We estimate the self-diffusion coefficient of particles in a moving suspension, taking into account pseudoturbulent and Brownian fluctuations.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 60, No. 5, pp. 720–724, May, 1991.