919 research outputs found

    Variability of Fe II Emission Features in the Seyfert 1 Galaxy NGC 5548

    Get PDF
    We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with those of the optical continuum. The amplitude of variability of the optical Fe II emission is 50% - 75% that of Hbeta and the ultraviolet Fe II emission varies with an even larger amplitude than Hbeta. However, accurate measurement of the flux in these blends proves to be very difficult even using excellent Fe II templates to fit the spectra. We are able to constrain only weakly the optical Fe II emission-line response timescale to a value less than several weeks; this upper limit exceeds all the reliably measured emission-line lags in this source so it is not particularly meaningful. Nevertheless, the fact that the optical Fe II and continuum flux variations are correlated indicates that line fluorescence in a photoionized plasma, rather than collisional excitation, is responsible for the Fe II emission. The iron emission templates are available upon request.Comment: 34 pages including 12 figures and 2 tables. Accepted for publication by ApJ (tentatively in vol. 626 June 10, 2005

    Post-Newtonian Theory for Precision Doppler Measurements of Binary Star Orbits

    Get PDF
    The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. We apply successive Lorentz transformations and the relativistic equation of light propagation to establish the exact treatment of Doppler effect in binary systems both in special and general relativity theories. As a result, the Doppler shift is a sum of (1) linear in c1c^{-1} terms, which include the ordinary Doppler effect and its variation due to the secular radial acceleration of the binary with respect to observer; (2) terms proportional to c2c^{-2}, which include the contributions from the quadratic Doppler effect caused by the relative motion of binary star with respect to the Solar system, motion of the particle emitting light and diurnal rotational motion of observer, orbital motion of the star around the binary's barycenter, and orbital motion of the Earth; and (3) terms proportional to c2c^{-2}, which include the contributions from redshifts due to gravitational fields of the star, star's companion, Galaxy, Solar system, and the Earth. After parameterization of the binary's orbit we find that the presence of periodically changing terms in the Doppler schift enables us disentangling different terms and measuring, along with the well known Keplerian parameters of the binary, four additional post-Keplerian parameters, including the inclination angle of the binary's orbit, ii. We briefly discuss feasibility of practical implementation of these theoretical results, which crucially depends on further progress in the technique of precision Doppler measurements.Comment: Minor changes, 1 Figure included, submitted to Astrophys.

    Expression of pinopodies in women with endometry hyperplasia without atipy and fertility disorders

    Get PDF
    Non-atypical endometrial hyperplasia (EH) most often occurs against a background of relative or absolute hyperestrogenism, responds to abnormal hormonal effects. In the reproductive age, the presence of EH can be a factor in the development of fertility disorders. The aim of the study was to learn the expression of pinopodes in ovulatory infertile women with non-atypical EH on the day of the implantation window. Under observation there were 196 women of reproductive age, of which 166 had been treated for infertility, and 30 conditionally gynecologically and somatically healthy, fertile women of the control group. A special examination of women included the determination in the endometrium by scanning electron microscopy of pinopodes’ expression. It was found that in women with non-atypical hyperplasia of the endometrium, areas without pinopodia were recorded in 47.59% of cases, pinopodes of small size - in 79.52% and abundant, small, thick microvilli - in 37.95%; the decrease in the incidence of developed pineapods in comparison with healthy prolific women was 2.72 times, that of pinopodes of large size was 3.39 and the small number of microvilli was 3.64, an increase in the occurrence of pinopodes of medium size 3.65, microvilli in moderate amounts - at 3.74. The authors conclude that the characteristic feature of endometrial pinopodes in EH is the presence of mosaicism of their shape (60.24%), size (64.46%) and the presence of numerous areas of absence of pinopodes (47.59%), which plays a significant role in disorders fertility

    Психологический отбор в игровых видах спорта на примере баскетбола

    Get PDF
    For the first time, an integrated approach based on the assessment of the technical and tactical skills of basketball players in combination with the psychological selection was used for selectionthe candidates for the Ukrainian cadet team. From the 144 athletes, who participated in the Ukrainian Championship, 36 players were selected based on the level of technical and tactical skills. According to the results of the psychological tests main characteristics of basketball players were defended and recommendations for coaches were given. As a result, 18 players, who were selected using psychological methods, had better technical and tactical mastery. They took part in the training process for preparation for the main competitions of the year (European Championship).Вперше застосовано комплексний підхід на основі оцінки техніко-тактичної мастерності баскетболістів в поєднанні з психологічним відбором кандидатів у кадетську збірну команду України для проведення навчально-тренувальних зборів. Зі 144 спортсменів, які брали участь у чемпіонаті України, відібрано 36 гравців по результатам визначення рівня техніко-тактичної майстерності. За підсумками проведених досліджень по вивченню психологічних характеристик баскетболістів відібрано 18 гравців для проведення навчально-тренувального процесу по підготовці до головних змагань року (чемпіонату Європи).Впервые был применен комплексный подход на основе оценки технико-тактического мастерства баскетболистов в сочетании с психологическим отбором кандидатов в кадетскую сборную Украины для проведения учебно-тренировочных сборов. Из 144 спортсменов, которые участвовали в чемпионате Украины, отобрано 36 игроков по результатам определения уровня технико-тактического мастерства. По итогам проведенных исследований по изучению психологических характеристик баскетболистов отобрано 18 игроков для проведения учебно-тренировочного процесса по подготовке к главным соревнованиям года (чемпионату Европы)

    Discovery of a Peculiar Dip from GX 301-2

    Full text link
    We present temporal and spectral properties of a unique X-ray dip in GX 301-2 as seen with Rossi X-ray Timing Explorer in May 2010. The X-ray pulsation from the source gradually declined prior to the dip, disappears for one spin cycle during the dip and is abruptly restored in the spin cycle immediately after the dip. Moreover, the phase-integrated spectrum of the source becomes softer before and during the dip and it quickly hardens again following the dip. Our findings indicate the fact that the mechanism for pulsations gradually turned off briefly and underlying dim and softer emission likely from the accretion column became observable in the brief absence of high level emission due to wind accretion.Comment: Accepted for publication in A&A Letter

    Deformation relief on D16AT alloy surface as indicator of prospects of operational loading history of aircraft structures

    Get PDF
    Формування деформаційного рельєфу (ДР) на поверхні алюмінієвого сплаву дає можливість розглядати його як індикатор історії експлуатаційного навантажування. В якості параметрів, які характеризують зміну ДР з напрацюванням, розглянуто параметри насиченості ДР, шорсткість поверхні і параметр пластичної деформації поверхні. Проведено порівняльний аналіз еволюції цих параметрів при регулярному і випадковому режимах навантажування.Deformation relief formation on D16T alloy alclad surface allows to consider it as indicator of operational loading history. Results of the deformation relief parameters evolution versus operating time are represented by parameter of deformation relief saturation, parameter of a surface roughness and surface plastic deformation. The results obtained under regular and variable amplitude loading are compared

    HYDROLYTIC STABILITY OF IMIDES OF DIFFERENT STRUCTURES

    Get PDF
    The conversion kinetics of N(o-carboxyphenyl)naphthalimide has been studied in buffer solutions over a pH range 5-12.6 and temperature range 25-70 °C. The naphthalimide hydrolysis is shown to be a reversible reaction. The mechanism of the alkaline hydrolysis of N(o- carboxyphenyl) phthalimide is proposed. The structure dependence of the imide hydrolytic stability is explained on the basis of the suggested mechanism

    Exploring social media recruitment strategies and preliminary acceptability of an mHealth tool for teens with eating disorders

    Get PDF
    (1) Background: The current study leveraged social media to connect with teens with EDs to identify population specific characteristics and to gather feedback on an mHealth intervention. (2) Methods: We recruited teens with EDs from social media in two phases: (1) Discovery Group, (2) Testing Group. The Discovery Group
    corecore