Optical spectroscopy of rare-earth ions doped KY(WO4)2 thin films

KY(WO4)2 thin films doped with Dy3+, Tb3+, Yb3+, were grown onto KY(WO4)2 substrates using liquid-phase epitaxy. Spectroscopic investigations of the grown layers were performed. Obtained results were compared with spectra given for bulk crystals. Upconversion experiments after direct Yb3+ excitation in Dy3+-Yb3+ and Tb3+-Yb3+ codoped layers will be also presented

The variation of the magnetic field of the Ap star HD~50169 over its 29 year rotation period

Context. The Ap stars that rotate extremely slowly, with periods of decades to centuries, represent one of the keys to the understanding of the processes leading to the differentiation of stellar rotation. Aims. We characterise the variations of the magnetic field of the Ap star HD 50169 and derive constraints about its structure. Methods. We combine published measurements of the mean longitudinal field of HD 50169 with new determinations of this field moment from circular spectropolarimetry obtained at the 6-m telescope BTA of the Special Astrophysical Observatory of the Russian Academy of Sciences. For the mean magnetic field modulus , literature data are complemented by the analysis of ESO spectra, both newly acquired and from the archive. Radial velocities are also obtained from these spectra. Results. We present the first determination of the rotation period of HD 50169, Prot = (29.04+/-0.82) y. HD 50169 is currently the longest-period Ap star for which magnetic field measurements have been obtained over more than a full cycle. The variation curves of both and have a significant degree of anharmonicity, and there is a definite phase shift between their respective extrema. We confirm that HD 50169 is a wide spectroscopic binary, refine its orbital elements, and suggest that the secondary is probably a dwarf star of spectral type M. Conclusions. The shapes and mutual phase shifts of the derived magnetic variation curves unquestionably indicate that the magnetic field of HD 50169 is not symmetric about an axis passing through its centre. Overall, HD 50169 appears similar to the bulk of the long-period Ap stars.Comment: 10 pages, 3 figures, accepted for publication in A&

New Statistical Methods For Systematizing The Nuclei Fission Fragments: Post-Scission Approach

A new statistical method for systematizing the nuclei fission fragments, investigation of their mass and charge spectra and neutron fission parameters has been suggested. In proposed method, the mass and charge yields of nucleons are determined from the equilibrium conditions of the nuclear fragments post-fission ensemble. Here we consider protons and neutrons of different fragments as statistically non-equivalent. The abilities of the proposed statistical method for explanation of the U, Pa, Th, Ac and Ra post-fission fragments ordering and neutron emission function calculation have been demonstrated.Comment: 11 pages, 5 figure

СУЧАСНІ УЯВЛЕННЯ ПРО ГРАНУЛОЦИТАРНИЙ АНАПЛАЗМОЗ ЛЮДИНИ

The aim of the work – to generalize some problems of etiology, epidemiological aspects, clinical signs, and laboratory diagnosis of human granulocytic anaplasmosis.Attention was paid that human granulocytic anaplasmosis proliferates in some European countries and Ukraine too as there are a lot of Ixodes ticks existence ranges. This disease has variety of clinical manifestations that’s why early diagnosis of disease needs meticulous laboratory conformation.In Ukraine examination of human granulocytic anaplasmosis are at an initial stage. It is quite possibly that in the majority of Ukrainian regions, human granulocytic anaplasmosis masks and is registered under the diagnosis of other nosologies, transmitted by Ixodes ticks. So, laboratory services which are responsible for diagnosis of such diseases need qualify improvement, and doctors have to know about this pathology and be able to suspect and confirm it. Special recommendations for different stages diagnosis of such human pathology beginning from primary medical care must be introduced.Мета роботи – узагальнити дані про етіологію, епідеміологічні особливості, клінічні прояви та підходи до лабораторної діагностики гранулоцитарного анаплазмозу людини (ГАЛ).Підкреслено, що ця хвороба набуває поширення в багатьох країнах Європи та Україні внаслідок наявності ареалів для її векторів – іксодових кліщів. Звернено увагу на строкатість її клінічних ознак, що ускладнює ранню діагностику захворювання і вимагає ретельного лабораторного підтвердження.Висновок. В Україні дослідження щодо ГАЛ перебувають на початковому етапі. З великою ймовірністю можна припустити, що на більшості території України ГАЛ реєструється під діагнозом інших нозологій, які передаються іксодовими кліщами, що пов’язано з подібністю окремих клінічних проявів цих інфекцій, а також недостатньою базою для їх лабораторної діагностики, з одного боку, та відсутністю настороженості дільничних лікарів та інфекціоністів щодо ГАЛ – з іншого

HD 965: An extremely peculiar A star with an extremely long rotation period

Context. One of the keys to understanding the origin of the Ap stars and their significance in the general context of stellar astrophysics is the consideration of the most extreme properties displayed by some of them. In that context, HD 965 is particularly interesting, as it combines some of the most pronounced chemical peculiarities with one of the longest rotation periods known. Aims. We characterise the variations of the magnetic field of the Ap star HD 965 and derive constraints about its structure. Methods. We combine published measurements of the mean longitudinal field of HD 965 with new determinations of this field moment from circular spectropolarimetry obtained at the 6-m telescope BTA of the Special Astrophysical Observatory of the Russian Academy of Sciences. For the mean magnetic field modulus , literature data are complemented by the analysis of ESO archive spectra. Results. We present the first determination of the rotation period of HD 965, P = (16.5+/-0.5) y. HD 965 is only the third Ap star with a period longer than 10 years for which magnetic field measurements have been obtained over more than a full cycle. The variation curve of is well approximated by a cosine wave. does not show any significant variation. The observed behaviour of these field moments is well represented by a simple model consisting of the superposition of collinear dipole, quadrupole and octupole. The distribution of neodymium over the surface of HD 965 is highly non-uniform. The element appears concentrated around the magnetic poles, especially the negative one. Conclusions. The shape of the longitudinal magnetic variation curve of HD 965 indicates that its magnetic field is essentially symmetric about an axis passing through the centre of the star. Overall, as far as its magnetic field is concerned, HD 965 appears similar to the bulk of the long-period Ap stars.Comment: 7 pages, 4 figures, accepted for publication in Astronomy & Astrophysics. arXiv admin note: text overlap with arXiv:1902.0586

The record-breaking rotational braking of the He strong CP star HD 37776

We study the long-term light and spectral variations in the He-strong magnetic chemically peculiar star HD 37776 (V901 Ori) to search for changes of its 1.5387 d period in 1976-2007. We analyze all published photometric observations and spectrophotometry in the HeI 4026 A line. The data were supplmented with 506 new (U)VB observations obtained during the last 2 observing seasons, 66 estimates of HeI equivalent widths on 23 CFHT spectrograms and 35 of the 6-m Zeeman spectrograms. All the 1895 particular observations heve been processed simultaneously. We confirm the previously suspected increase of the period in HD 37776 which is a record-breaking among CP stars. The mean rate of the period increase during the last 31 years is 0.541+-0.020 s per year. We interpret this ongoing period increase as the slowing down of the star's surface rotation due to momentum loss through events and processes in its magnetosphere.Comment: 3 pages, 1 figure, Proceedings of the "CP#AP Workshop", Vienna, 10.-14.Sept.2007, eds.J.Ziznovsky, J.Zverko, E.Paunzen, M.Netopil, will be published in Contrib. Astron. Obs. Skalnate Ples