131 research outputs found

    Pc5 waves generated by substorm injection: a case study

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    We analyzed the spectral-polarized characteristics of Pc5 ULF waves observed on 17 September 2000 after the 03:20:25 UT substorm onset with the satellites GOES 8 and 10 located east and west of the onset location. In the course of the event, the wave polarization changed from mixed (between toroidal and poloidal) to poloidal, and then to mixed again. The hodogram of magnetic field oscillations rotated counterclockwise at GOES 8, and clockwise at GOES 10. It is suggested that the satellites detected the waves generated by the substorm injected clouds of the charged particles drifting in the magnetosphere in the opposite azimuthal directions: GOES 8 (located east of the substorm onset) detected the wave generated by an electron cloud, and GOES 10 (west of the onset) detected the wave generated by a positive ion cloud. This interpretation is confirmed by the energetic particles data recorded by LANL satellites

    RISKS OF OPEN INNOVATION

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    The article describes a model of open innovation and analyzes the main risks of using this model

    Comparison of mode thresholds in microdisk and microring lasers with uniform and non-uniform gain profiles

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    © 2016 IEEE.We study the modes of two-dimensional (2-D) microdisk and microring lasers using the electromagnetic theory, namely considering them as dielectric resonators with ring-like active regions having radially non-uniform gain profile. On the approximation of the gain profile with a stepped function, we reduce the considered eigenvalue problems to transcendental equations and solve them numerically. Finally we compare the spectral characteristics, i.e. the lasing frequencies and the associated values of threshold material gain, of these resonators with previously obtained solutions for resonators with uniform gain profile

    Comparison of the lasing modes of a microdisk and a microring

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    © 2015 IEEE. Microcavity lasers shaped as thin circular disks are famous for the ultra-low thresholds of their whispering-gallery (WG) modes. We considered a two-dimensional (2-D) model of such a laser in free space with a ring-like active region and compared the characteristics of its modes with the modes of an active microring, i.e. a similar disk with a concentric hole. The comparison showed that a microring has considerable rarefaction effect in terms of emission thresholds, accompanied by the blue-shift of emission spectra. If the ring becomes narrower than half-wavelength in material, then all lasing modes obtain catastrophically high thresholds

    Electromagnetic analysis of optimal pumping of a microdisk laser with a ring electrode

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    © 2016, Springer-Verlag Berlin Heidelberg.We study the lasing modes of microdisk lasers with ring-like electrodes or active regions, in two-dimensional (2-D) formulation. The considered eigenvalue problem is adapted to the extraction of both modal spectra and thresholds from the Maxwell equations with exact boundary conditions. We reduce it to a transcendental equation and solve it numerically. The obtained lasing frequencies and the associated values of threshold material gain of the ring-pumped laser are compared with similar quantities of the fully active microdisk. This comparison shows that the optimal position of the active ring is shifted inward from the disk rim. Its location and width can be used as an engineering instrument to manipulate the thresholds. This effect is explained using the optical theorem and overlap coefficients

    Late Antiquity: The Regional Specific Nature of Intellectual Tradition

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    The primary purpose of the study is to investigate the specifics of the intellectual tradition prevailing in some regions of the Late Antique world. For the purpose of a comprehensive review of the problem, the authors focus on well-known intellectuals of the 5th–6th centuries, representing Gaul (Ausonius, Sidonius, Ennodius et al.), Alexandria (John Philoponus, Hypatia, Sinesius of Cyrene et al.), Africa (Fulgentius, Priscian, Corippus), Isauria (Candidus Isaurus). Despite the fact that, under the influence of objective factors (Christianization, barbarians), the intellectual tradition changed from its ancient model to the medieval one, it fulfilled its most important task - to preserve the best from the treasury of ancient thought and adapt the ancient heritage to a changing world. In conclusion, the outcomes of the study demonstrate various examples of intellectual tradition and the fortunes of “people of written culture” (literati)

    Late Antiquity: the regional specific nature of intellectual tradition

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    The primary purpose of the study is to investigate the specifics of the intellectual tradition prevailing in some regions of the Late Antique world. For the purpose of a comprehensive review of the problem, the authors focus on wellknown intellectuals of the 5th-6th centuries, representing Gaul (Ausonius, Sidonius, Ennodius et al.), Alexandria (John Philoponus, Hypatia, Sinesius of Cyrene et al.), Africa (Fulgentius, Priscian, Corippus), Isauria (Candidus Isaurus

    State of microcirculation and free-radical processes of periodontal tissues in smoking dependent patients with chronic generalized periodontitis associated with chronic hyperacid gastritis

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    The aim of the work was to determine the state of microcirculation and free radical processes of periodontal tissues in smoking dependent patients with chronic generalized periodontitis associated with chronic hyperacid gastritis. Materials and methods: We examined 90 patients (men and women) aged 25 to 44 years, who were divided into 3 groups: the first group - 48 smoking patients with chronic generalized periodontitis and chronic hyperacid gastritis associated with Helicobacter pylori; the second group - 22 patients with chronic generalized periodontitis and chronic hyperacid gastritis associated with Helicobacter pylori, without the bad habit; the third group - control, consisted of 20 healthy individuals. The smoking patients were randomly divided into two subgroups: patients of the first subgroup (G1.1) received the basic therapy of chronic generalized periodontitis and the proposed treatment and prevention complex; the patients in the second subgroup (G1.2) received basic therapy for chronic generalized periodontitis and ultraphonophoresis with placebo. Results: The use of treatment and prevention complex in smoking dependent patients and patients without the bad habit with chronic generalized periodontitis and chronic hyperacid gastritis associated with Helicobacter pylori demonstrated a positive dynamics of the functional characteristics of microcirculation and the balance in the lipid peroxidation – antioxidant system. Conclusions: So, the use of the proposed treatment and prevention complex had a positive effect on the state of microcirculation and free radical processes of periodontal tissues both at the near and long-term follow up, even under conditions of chronic hyperacid gastritis and the risk factor – smoking
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