On the source of auroral kilometric radiation

The radiation pattern has been determined on the basis of the comparative analysis of auroral kilometric radiation (AKR) received in the space-diversity mode by two satellites, Interball-2 and Polar. The radiation propagates in a cone with an opening angle ∼±25° and the axis aligned with the local magnetic field. The results con-firm the theoretical estimates that the source boundaries play a significant role in the generation of the auroral kilometric radiation and in the formation of the radiation pattern. Original Russian Text ? M.M. Mogilevsky, T.V. Romantsova, J. Hanasz, T.M. Burinskaya, R. Schreiber, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 11, pp. 819–821.     

On the source of auroral kilometric radiation

The radiation pattern has been determined on the basis of the comparative analysis of auroral kilometric radiation (AKR) received in the space-diversity mode by two satellites, Interball-2 and Polar. The radiation propagates in a cone with an opening angle ～±25° and the axis aligned with the local magnetic field. The results con-firm the theoretical estimates that the source boundaries play a significant role in the generation of the auroral kilometric radiation and in the formation of the radiation pattern.     

Direct measurements of auroral kilometric radiation in a limited source

The enhancement of auroral kilometric radiation near its lowest frequency has been detected in the polar edge of the auroral zone in the POLRAD experiment with the INTERBALL-2 satellite. The difference between the local electron cyclotron frequency and the lowest frequency of enhanced radiation is 8–20 kHz, indicating the closeness to the source of auroral kilometric radiation. According to the detailed analysis of low-frequency auroral kilometric radiation, its amplitude is larger than the “background” values by a factor of 20–70 and has amplitude modulation with characteristic periods of 40-60 s. The increase in the intensity at low frequencies is attributed to the intersection of the source region by the satellite and the detection of waveguide modes in it.     

Effect of the matrix composition on the activity of metal oxide catalysts in CVD synthesis of carbon nanotubes

Citrate-nitrate method was used to synthesize (Fe,Co)/MgO-Al₂O₃, (Fe,Mo)/MgO-Al₂O₃, and (CoMo)/MgO-Al₂O₃ catalysts for production of carbon nanotubes. Multi-walled nanotubes were formed on these catalysts by catalytic pyrolysis of a propane-butane mixture.     

On an asymptotic goodness-of-fit test for a two-parameter gamma-distribution

In this paper, a formula for the test statistic is given for a two-parameter gamma-distribution which involves the first four moments. Translated fromStatisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 15–24, Perm, 1993.     

Thermal conductivity of glassy primary mono-hydroxylalcohols

Thermal conductivity κ(T) data for homologous series of primary mono-hydric alcohols – methanol, ethanol, 1-propanol, 1-butanol – within their molecular glass states are analyzed within the temperature region stretching from 2 K up to the glass transition T_g. Below 7 K κ(T) increases with the number of carbon atoms in the molecule. Furthermore, its temperature dependence exhibits a behavior akin to that predicted by the phenomenological model of soft potentials (SPM). The data are then rationalized in terms of the SPM parameters such as characteristic energy W and the parameter ¯С which measures the strength of the coupling of acoustic modes with two-level systems. The dependence of such parameters upon the molecular mass of the alcohol seems to agree with the SPM predictions. The parameters ¯С and W were used to calculate the boson peak energies. The values obtained agree well with literature data.