210 research outputs found

    Determination of characteristics of newly discovered eclipsing binary 2MASS J18024395 +4003309 = VSX J180243.9+400331

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    During processing the observations of the intermediate polar 1RXS J180340.0+401214, obtained 26.05.2012 at the 60-cm telescope of the Mt. Suhora observatory (Krakow, Poland), variability of 2MASS J18024395+4003309 was discovered. As this object was not listed in the "General Catalogue of Variable Stars" or "Variable Stars Index", we registered it as VSX J180243.9+400331. Additionally we used 189 separate observations from the Catalina Sky Survey spread over 7 years. The periodogram analysis yields the period of 0d.3348837{\pm}0d.0000002.The object was classified as the Algol-type eclipsing binary with a strong effect of ellipticity. The depths of the primary and secondary minima are nearly identical, which corresponds to a brightness (and maybe) mass ratio close to 1. The statistically optimal degree of the trigonometric polynomial n=4. The most recent minimum occurred at HJD 2456074.4904. The brightness range from our data is 16.56-17.52 (V), 16.18-17.08 (R). The NAV ("New Algol Variable") algorithm was applied for statistically optimal phenomenological modeling and determination of corresponding parameters

    Plasma measurements conducted in the vincinity of Venus on the spacecraft VENERA-4

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    Plasma flux measurements in vicinity of Venus by charged particle traps on Venera-4 spacecraf

    Detection of white dwarf spin period variability in the intermediate polar V2306 Cygni

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    Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on matter flows. They often exhibit spin-up or spin-down of the white dwarf, while some systems exhibit more complex behaviour of the spin period change. We monitor changes of the spin periods of white dwarfs in a sample of close binary systems to study interaction of the magnetic field and accretion processes as well as evolution of intermediate polars. Within the framework of our intermediate polar monitoring program, we obtained photometric CCD observations at several observatories. Two-period trigonometric polynomial fitting was used for determination of extrema timings. The (O-C) analysis was performed to study the variability of the orbital and spin periods of the systems. Using data taken during 9 years of observations of the magnetic cataclysmic variable V2306 Cygni (formerly known as 1WGA J1958.2+3232), we detected the spin period variability which shows a spin-up of the white dwarf with a characteristic time of (53±5)104(53\pm5)\cdot10^4 years. The value of the spin period was 733.33976733.33976 seconds with the formal accuracy of 0.000150.00015 seconds. We derived an improved value of the orbital period of the system to be 4.371523±0.0000094.371523\pm0.000009 hours.Comment: Accepted to MNRAS 2019 July 23. 5 pages, 3 figures, supporting data onlin

    The magnetic field of Mars estimated from the data of plasma measurements by Soviet artificial satellites of Mars

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    The dimensions of the obstacle forming the shock wave of Mars are estimated by use of electron trap data from Mars 2, 3, and 5. The mean altitude of the obstacle at the subsolar point can be convincingly explained if the obstacle is the magnetosphere of Mars. On the assumption that Mars has its own dipole magnetic field, the magnetic moment of Mars is estimated, Mm approximately equal to 2 x 10 to the twenty second power gs x cubic cu

    Sorption of hydrocarbons by leached chernozem

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    The sorption of n-octane, n-nonane, n-decane, decalin, and p-xylene on oven-dried and differently wetted leached chemozem, zeolite-bearing rock, and limestone was studied using static headspace-gas chromatography. It was found that leached chernozem exhibits a high capacity for selective sorption of hydrocarbons and has significantly heterogeneous sorption sites. Thermodynamic parameters of sorption, specific surface of sorbents, and the fractal dimension of soil surface were determined. An increase in the soil moisture content significantly inhibited the sorption of the hydrocarbons studied. Copyright © 2003 by MAIK "Nauka/Interperiodica" (Russia)

    РОЗРОБЛЕННЯ МОДЕЛІ ОЦІНЮВАННЯ ЕКОНОМІЧНОЇ БЕЗПЕКИ ЗАКЛАДІВ ВИЩОЇ ОСВІТИ

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    In the article the model of economic security of institutions of higher education is developed using regression analysis based on multiple regression,it takes into account the relationship between aggregate indicators (integral indicators) by groups and an integral indicator of the economic security of higher education institutions.The instrument for development evaluationmodelof economic security of higher education institutions are methodical approach are methodical approach(taking into account the principles of development balanced scorecard) designed hierarchically using factor analysis(method of principal component), using weighted valuesfor calculating the integral index of groups and integral indicator of economic security institutions of higher education.Taking into account the necessity of interaction of the state, higher education institutions and employers on the labor market the use of the model evaluation of economic security of higher education institutions of not the higher education institutions as separate entities, but as important elements of the socio-economic system hierarchically provides an opportunity to assess the impact indicators on economic security of higher education institutions and promote the effectiveness of the use of state regulation instruments in the field of higher education.В статье разработана модель экономической безопасности заведений высшего образования с использованием регрессионного анализа на основе множественной регрессии, она учитывает зависимость между агрегированными показателями (интегральными индикаторами) по группам и интегральным индикатором экономической безопасности высших учебных заведений. Инструментом для разработки модели оценки экономической безопасности высших учебных заведений является методический подход (с учетом принципов разработки сбалансированной системы показателей), разработан иерархически с помощью факторного анализа (метода главных компонент) с использованием весовых значений показателей.Использование разработанной модели дает возможность провести оценку влияния показателей на состояние экономической безопасности заведений высшего образования и способствовать повышению эффективности использования инструментов государственного регулирования в сфере высшего образования.У статті розроблена модель економічної безпеки закладів вищої освіти з використанням регресійного аналізу на основі множинної регресії, вона враховує залежність між агрегованими показниками (інтегральними індикаторами) за групами та інтегральним індикатором економічної безпеки закладів вищої освіти. Інструментом для розроблення моделі оцінювання економічної безпеки закладів вищої освіти є методичний підхід (з урахуванням принципів розробки збалансованої системи показників), розроблений ієрархічно за допомогою факторного аналізу (методу головних компонент) із використанням вагових значень показників.Використання розробленої моделі дає можливість провести оцінювання впливу показників на стан економічної безпеки закладів вищої освіти й сприяти підвищенню ефективності використання інструментів державного регулювання у сфері вищої освіти

    Sorption of volatile organic compounds and their mixtures on montmorillonite at different humidity

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    The vapor-phase sorption of volatile organic compounds (VOCs), i.e. n-hexane, benzene and methanol, along with sorption of their binary mixtures, i.e. benzene/n-hexane and benzene-methanol, on montmorilllonite with different water content was studied. The absolutely dry mineral did not exhibit selectivity towards the studied VOCs sorbed separately. The hydration inhibited sorption of hydrocarbons and promoted that of methanol because of intercalation of its molecules to the interlayer space of the swelling mineral and dissolution in the water films on the external mineral surface. Unlike separate sorption of benzene and n-hexane, sorption of their binary mixture on the montmorillonite, even equal by volume, was selective. The components shared the same sorption sites with benzene being more active due to its ability to form the donor-acceptor complexes with the mineral surface in addition to Van-der-Waals interactions. Opposite, in the benzene/methanol mixture the undoubted predominance of hydrophilic methanol over benzene was revealed, which increased with increasing humidity and was significantly stronger compared to the differences in sorption of methanol and benzene sorbed separately. In the binary mixtures unequal by volume, preadsorption played an important role in VOCs competition with sorption of aliphatic n-hexane being suppressed stronger than that of aromatic benzene. In the benzene/methanol mixture, methanol was predominantly sorbed at all the studied volume ratios and hydration degrees, occupying its specific sorption sites. Hydration of the montmorillonite caused the reverse impact on the sorption of benzene and methanol. As a result, at the full hydration state methanol sorption in the mixture reached that of the pure methanol. © 2014 Elsevier B.V
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