White light-emitting diodes for optical stimulation of aluminium oxide in OSL dosimetry

The results of comparative investigations into the optically stimulated luminescence (OSL) of anion-defective corundum excited by radiation of blue and white light-emitting diodes (LEDs) are reported. The continuous-wave OSL (CW-OSL) measurements showed that the white LED (compared to the blue LED) and the chosen geometry allow the amplitude of the OSL response to increase by a factor of more than 40 and the dosimetric information readout time to decrease by a factor of 20. The effect of deep traps on the behavior of the CW-OSL curves of anion-defective corundum was studied. It was found that the filling of deep traps essentially increases the TL yield with a dosimetric peak at 450 K and the CW-OSL-yield under stimulation with blue and white LEDs. It was also found that this filling causes a considerable change in the shape of the OSL curve and the time parameters of the decay. © 2013 Elsevier Ltd. All rights reserved

Phase space measure concentration for an ideal gas

We point out that a special case of an ideal gas exhibits concentration of the volume of its phase space, which is a sphere, around its equator in the thermodynamic limit. The rate of approach to the thermodynamic limit is determined. Our argument relies on the spherical isoperimetric inequality of L\'{e}vy and Gromov.Comment: 15 pages, No figures, Accepted by Modern Physics Letters

The peculiarities of anion vacancy distribution and the relationship between their concentration and the Tld-500 detector Tl output

A procedure has been developed for estimating the uniformity of anion vacancy distribution in TLD-500 detectors on the basis of anion-deficient corundum single crystals. Vacancy distribution topograms were constructed for TLD-500 detectors with different sensitivities to irradiation. Analysis of the topograms provided correlations between average anion vacancy concentrations and thermoluminescent (TL) yields in the main peak with a maximum at 450 K. To confirm the pattern of regularities, the effects of high-temperature annealing of TLD-500 samples in air at T = 1700 K were studied depending on its duration. Increasing the annealing time from 40 to 105 minutes was found to correlatedly reduce the anion vacancy concentrations and TL-yields in the basic and high-temperature peaks at 450 and 830 K, respectively. © Published under licence by IOP Publishing Ltd.The work was partly supported by the Russian Foundation for Basic Research (Grant No. 18-08-00093-a) and UB RAS (pr. 18-11-2-2)

A note on coulhon type inequalities

T. Coulhon introduced an interesting reformulation of the usual Sobolev inequalities. We characterize Coulhon type inequalities in terms of rearrangement inequalitie

Integral isoperimetric transference and dimensionless Sobolev inequalities

We introduce the concept of Gaussian integral isoperimetric transfer and show how it can be applied to obtain a new class of sharp Sobolev-Poincaré inequalities with constants independent of the dimension. In the special case of Lq spaces on the unit n-dimensional cube our results extend the recent inequalities that were obtained in Fiorenza et al. (2012) using extrapolation

Modes of convergence : Interpolation Methods I

In the present paper we explore an approximation theoretic approach to some classical convergence theorems of real analysis. The background of this paper is the intuition that some of the usual compactness theorems on various modes of convergence in classical analysis are based on suitable ways of obtaining good decompositions of functions to exploit rates of approximation, cancellations, or appropriate control of sizes that can be controlled by the basic functionals of real interpolation