34 research outputs found

    Energy confinement in the torsatron Uragan-3M during the RF-heating mode

    No full text
    Energy confinement time of plasma in torsatron U-3M was measured both during quasi-stationary stady of RF-discharge and after RF-power cut-off. Power absorbed by plasma in the confinement region was estimated. A mechanism which explain the plasma density behavior in the confinement region is proposed.Експериментально визначено енергетичний час життя плазми під час квазістаціонарної стадії ВЧ-розряду і при вимкненні ВЧ-розряду в торсатроні У-3М. Оцінена частка потужності, що випромінюється ВЧ-антеною, яка поглинається плазмою в області її утримання. Запропоновано можливий механізм, що пояснює поведінку щільності плазми в області утримання.Экспериментально определено энергетическое время жизни плазмы во время квазистационарной стадии ВЧ- разряда и при выключении ВЧ-разряда в торсатроне У­-3М. Оценена доля мощности, излучаемой ВЧ-антенной, которая поглощается плазмой в области ее удержания. Предложен возможный механизм, объясняющий поведение плотности плазмы в области удержания

    Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results

    Get PDF
    The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can supply significant amounts of energy to the interface region and corona. In recent years an abundance of high-resolution observations from state-of-the-art facilities have provided new and exciting ways of disentangling the characteristics of oscillatory phenomena propagating through the dynamic chromosphere. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate the role waves play in supplying energy to sustain chromospheric and coronal heating. Here, we review the recent progress made in characterising, categorising and interpreting oscillations manifesting in the solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review

    Two models of the sound-signal frequency dependence on the animal body size as exemplified by the ground squirrels of Eurasia (mammalia, rodentia)

    No full text
    Dependence of the sound-signal frequency on the animal body length was studied in 14 ground squirrel species (genus Spermophilus) of Eurasia. Regression analysis of the total sample yielded a low determination coefficient (R2 = 26%), because the total sample proved to be heterogeneous in terms of signal frequency within the dimension classes of animals. When the total sample was divided into two groups according to signal frequency, two statistically significant models (regression equations) were obtained in which signal frequency depended on the body size at high determination coefficients (R2 = 73 and 94% versus 26% for the total sample). Thus, the problem of correlation between animal body size and the frequency of their vocal signals does not have a unique solution. © 2017, Pleiades Publishing, Ltd

    Two models of the sound-signal frequency dependence on the animal body size as exemplified by the ground squirrels of Eurasia (mammalia, rodentia)

    No full text
    Dependence of the sound-signal frequency on the animal body length was studied in 14 ground squirrel species (genus Spermophilus) of Eurasia. Regression analysis of the total sample yielded a low determination coefficient (R2 = 26%), because the total sample proved to be heterogeneous in terms of signal frequency within the dimension classes of animals. When the total sample was divided into two groups according to signal frequency, two statistically significant models (regression equations) were obtained in which signal frequency depended on the body size at high determination coefficients (R2 = 73 and 94% versus 26% for the total sample). Thus, the problem of correlation between animal body size and the frequency of their vocal signals does not have a unique solution. © 2017, Pleiades Publishing, Ltd

    Sex Accent and Biphonation in the Sound Signal of Ground Squirrels (Mammalia, Rodentia)

    No full text
    Abstract: The alarm call of the little ground squirrel (Spermophilus pygmaeus), like those of six other Eurasian ground squirrels, contains a high-frequency component. In males, the peak and maximum frequencies of the high-frequency component are higher than in females. Biphonation of the alarm calls of Sp. pygmaeus, Sp. musicus, Sp. xanthoprymnus, and Sp. alaschanicus has been demonstrated, with the low- and high-frequency components generated by different sources in the vocal tract. The material was collected in the field. © 2019, Pleiades Publishing, Ltd

    Destruction of Sound Signal Structure in a Peripheral Population (as Exemplified by the Gray Marmot Marmota baibacina)

    No full text
    Abstract: The variability of the alarm call of the gray marmot (Marmota baibacina) in the peripheral population in the valley of the Arpa River (Kyrgyzstan) is described. It was earlier reported that this population lived together with the red marmot (M. caudata). The authors did not find the red marmot there. Two forms of aberrations were found in the edge population of the gray marmot: amplitude modulation and no pause between the components. The destruction of the signal structure that is typical of the species is probably associated with the disruption of gene flow and does not contain clear signs of hybridization. The material was collected under the field conditions. © 2020, Pleiades Publishing, Ltd
    corecore