53 research outputs found

    Upgrade of the Argentine Islands INTERMAGNET observatory at Akademik Vernadsky station, Antarctica

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    The article describes the main features of upgrading the magnetometric complex based on the LEMI-025 variometer in January-April 2019 at the geomagnetic observatory (code AIA) of the Ukrainian Antarctic Akademik Vernadsky station.У статті описані основні особливості модернізації магнітометричного комплексу на базі варіометра LEMI-025 у січні-квітні 2019 року в геомагнітній обсерваторії (код AIA) Української антарктичної станції «Академік Вернадський»

    A New Algorithm for Analysis of Experimental Mössbauer Spectra

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    A new approach to analyze the nuclear gamma resonance (NGR) spectra is presented and justified in the paper. The algorithm successively spots the Lorentz lines in the experimental spectrum by a certain optimization procedures. In Mössbauer spectroscopy, the primary analysis is based on the representation of the transmission integral of an experimental spectrum by the sum of Lorentzians. In the general case, a number of lines and values of parameters in Lorentzians are unknown. The problem is to find them. In practice, before the experimental data processing, one elaborates a model of the Mössbauer spectrum. Such a model is usually based on some additional information. Taking into account physical restrictions, one forms the shape of the lines which are close to the normalized experimental Mössbauer spectrum. This is done by choosing the remaining free parameters of the model. However, this approach does not guarantee a proper model. A reasonable way to construct a structural NGR spectrum decomposition should be based on its model-free analysis. Some model-free methods of the NGR spectra analysis have been implemented in a number of known algorithms. Each of these methods is useful but has a limited range of application. In fact, the previously known algorithms did not react to hardly noticeable primary features of the experimental spectrum, but identify the dominant components only. In the proposed approach, the difference between the experimental spectrum and the known already determined part of the spectral structure defines the next Lorentzian. This method is effective for isolation of fine details of the spectrum, although it requires a well-elaborated algorithmic procedure presented in this paper

    On certain approaches to the control methods development for the precipitation formation processes in convective clouds

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    The article aims at searching for the optimal way of emission of ice nucleating agent in convective cloud in order to prevent ‎formation of harmful hail by analyzing simulations of this process within a numerical model ‎of cloud‎. The state of the physics of clouds and active influences on them is discussed. It is noted that at the present time studies of the regularities of the formation and development of clouds as a whole begin taking into account their systemic properties. The main directions of research at the next stage of its development are discussed. The features of the existing methods of active action on convective clouds are noted, the main tasks encountered in the development of methods for controlling sedimentation in convective clouds by introducing reagents are formulated. It is noted that research on the development of methods for active influence on clouds should be conducted on the basis of new and more effective approaches, which should be based on the extensive use of mathematical modeling. Some approaches to solving this problem are discussed. According to the authors, the most promising of them are approaches based on the theory of optimal control and bifurcation theory. Some results of numerical modeling of the active effect on convective clouds are given

    Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

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    Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

    A NEW ALGORITHM FOR ANALYSIS OF EXPERIMENTAL MÖSSBAUER SPECTRA

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    A new approach to analyze the nuclear gamma resonance (NGR) spectra is presented and justified in the paper. The algorithm successively spots the Lorentz lines in the experimental spectrum by a certain optimization procedures. In Mössbauer spectroscopy, the primary analysis is based on the representation of the transmission integral of an experimental spectrum by the sum of Lorentzians. In the general case, a number of lines and values of parameters in Lorentzians are unknown. The problem is to find them. In practice, before the experimental data processing, one elaborates a model of the Mössbauer spectrum. Such a model is usually based on some additional information. Taking into account physical restrictions, one forms the shape of the lines which are close to the normalized experimental Mössbauer spectrum. This is done by choosing the remaining free parameters of the model. However, this approach does not guarantee a proper model. A reasonable way to construct a structural NGR spectrum decomposition should be based on its model-free analysis. Some model-free methods of the NGR spectra analysis have been implemented in a number of known algorithms. Each of these methods is useful but has a limited range of application. In fact, the previously known algorithms did not react to hardly noticeable primary features of the experimental spectrum, but identify the dominant components only.  In the proposed approach, the difference between the experimental spectrum and the known already determined part of the spectral structure defines the next Lorentzian. This method is effective for isolation of fine details of the spectrum, although it requires a well-elaborated algorithmic procedure presented in this paper

    Solar Cycle-Modulated Deformation of the Earth–Ionosphere Cavity

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    The Earth–ionosphere cavity resonator is occupied primarily by the electromagnetic radiation of lightning below 100 Hz. The phenomenon is known as Schumann resonances (SR). SR intensity is an excellent indicator of lightning activity and its distribution on global scales. However, long-term measurements from high latitude SR stations revealed a pronounced in-phase solar cycle modulation of SR intensity seemingly contradicting optical observations of lightning from satellite, which do not show any significant solar cycle variation in the intensity and spatial distribution of lightning activity on the global scale. The solar cycle-modulated local deformation of the Earth–ionosphere cavity by the ionization of energetic electron precipitation (EEP) has been suggested as a possible phenomenon that may account for the observed long-term modulation of SR intensity. Precipitating electrons in the energy range of 1–300 keV can affect the Earth–ionosphere cavity resonator in the altitude range of about 70–110 km and modify the SR intensities. However, until now there was no direct evidence documented in the literature supporting this suggestion. In this paper we present long-term SR intensity records from eight stations, each equipped with a pair of induction coil magnetometers: five high latitude (|lat| \u3e 60°), two mid-high latitude (50° \u3c |lat| \u3c 60°) and one low latitude (|lat| \u3c 30°). These long-term, ground-based SR intensity records are compared on the annual and interannual timescales with the fluxes of precipitating 30–300 keV medium energy electrons provided by the POES NOAA-15 satellite and on the daily timescale with electron precipitation events identified using a SuperDARN radar in Antarctica. The long-term variation of the Earth–ionosphere waveguide’s effective height, as inferred from its cutoff frequency, is independently analyzed based on spectra recorded by the DEMETER satellite. It is shown that to account for all our observations one needs to consider both the effect of solar X-rays and EEP which modify the quality factor of the cavity and deform it dominantly over low- and high latitudes, respectively. Our results suggest that SR measurements should be considered as an alternative tool for collecting information about and thus monitoring changes in the ionization state of the lower ionosphere associated with EEP

    КЛИНИКО-ЛАБОРАТОРНЫЕ СОПОСТАВЛЕНИЯ ПРИ ПОСТМЕНОПАУЗАЛЬНОМ ОСТЕОПОРОЗЕ С НОРМАЛЬНОЙ И ПОВЫШЕННОЙ ФУНКЦИЕЙ ОКОЛОЩИТОВИДНЫХ ЖЕЛЕЗ

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    The need for a comprehensive diagnostic approach to the patients suffering osteoporosis is determined by high medical and social significance and disabling nature of complications. The objective of this research is to estimate features of calcium and bone metabolism depending on functional status of parathyroid glands. The study involved 150 post-menopausal women with a low bone mineral density. All patients underwent clinical and laboratory examination including a functional test for evaluating the enteral absorption of calcium. More expressed disorders of calcium and bone metabolism have been identified in patients with the development of secondary hyperparathyroidism in conjunction with the violation of enteral calcium absorption.Необходимость комплексного диагностического подхода к больным с остеопорозом объясняется высокой медико- социальной значимостью и инвалидизирующим характером осложнений. Целью исследования явилось изучение метаболизма кальция и костной ткани в зависимости от функционального состояния околощитовидных желез. Обследованы 150 женщин с остеопорозом, находящихся в постменопаузе. Выполнено полное клинико-лабораторное обследование, в том числе проведен функциональный тест с энтеральной нагрузкой кальцием, позволяющий косвенно оценить абсорбцию кальция в кишечнике. Показано более глубокое нарушение фосфорно-кальциевого обмена и более выраженное снижение минеральной плотности костной ткани у женщин в условиях развития вторичног
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