Precise determination of the absolute intensities of the gamma-ray lines of 235U and some 238U daughters

2006 ◽  
Vol 568 (2) ◽  
pp. 734-738 ◽  
Author(s):  
F.S. Al-Saleh ◽  
Al-J.H. Al-Mukren ◽  
M.A. Farouk
Keyword(s):  
Gamma Ray ◽  
Precise Determination ◽  
Absolute Intensities ◽  
The Absolute

Determination of the half-life and the absolute photon emission intensities for the main gamma-ray energies of 124I

2021 ◽  
Vol 167 ◽  
pp. 109455
Author(s):  
L. Pibida ◽  
D.E. Bergeron ◽  
B. Zimmerman ◽  
R. Fitzgerald ◽  
J.T. Cessna ◽  
...  
Keyword(s):  
Half Life ◽  
Gamma Ray ◽  
Photon Emission ◽  
The Absolute

scholarly journals ASTROMETRIC RESEARCH IN UKRAINE AT THE XIX – BEGINNING OF XX CENTURIES

2021 ◽  
Vol 34 ◽  
pp. 5-10
Author(s):  
T.G. Artemenko
Keyword(s):  
Southern Hemisphere ◽  
Solar Physics ◽  
Precise Determination ◽  
Scientific Activity ◽  
Astronomical Observatory ◽  
Earth Tides ◽  
Genealogical Tree ◽  
Main Research ◽  
The Absolute

The paper presents the stages of development of astrometric research at the Ukrainian observatories in the ХIХ – beginning of ХХ century. They are related to the establishment of university astronomical observatories in Kyiv (1845), Odessa (1871), Kharkiv (1888). Mykolaiv Naval observatory was founded in 1821 for navigation needs with assistance of Admiral A.S. Greig. The absolute catalogs compiled at the Pulkovo and Mykolaiv Observatories made a significant contribution to the international work of compilation of a FK3 system. Special attention is paid to the scientific activity of the oldest observatory at the territory of Ukraine – the Astronomical observatory of L’viv University (1771). Researches at this observatory were mainly concerned with the field of geodesy and meteorology. Despite the short first period of scientific activity (near 10 years), it gave impetus to some famous scientists. At the last decades of ХIХ century observatory of the L’viv University renewed their activity in astrometry, solar physics, and astrophysics. Southern departments of Pulkovo observatory in Odessa (1899) and Mykolaiv (1912) played an important role in extension of Pulkovo absolute catalogues to the southern hemisphere. Systematic observations of the Sun conducted at these departments contributed to the more precise determination of the position of vernal equinox.  In ХIХ century Ukrainian observatories participated in the international programs, such as AGK (Astronomischer Gesellschaft Katalog), the photographic catalog “Carte du Ciel” (France). Among the actual observational programs were surveys of zodiacal stars (M.P.Ditchenko in Kyiv), near-pole stars (V.I.Fabritius, R.P.Fogel, M.P.Ditchenko in Kyiv, L.O.Struve and K.N.Kuz'menko in Kharkiv, I.O.Djukov, L.F.Cherniev in Odessa). In the frame of observations of Bonner Durchmusterung (BD) and its southern continuation, organized by the German Astronomical Society, observations of the equatorial zone were provided by I.E. Kortazzi at Mykolaiv observatory, B.V.Novopashenny at the Astronomical Observatory of Odessa University in 1930s years. Needs of astrophotography lead to the creation of the “Сatalog of the faint stars” project. In 1932 at the First Astrometric Conference in Leningrad, the Pulkovo astronomers Gerasimovich B.P and Dniprovsky M.I. suggested the idea of using eхtragalactic nebulae as the reference objects for determination of the absolute motion of the stars. Among the tasks to be solved at the project was compilation of a general catalogue (KSZ) and a fundamental catalog of faint stars (FKSZ). It was planned to involve all the meridian instruments of the USSR as well as foreign ones, especially in the southern hemisphere. The idea of orientation of the KSZ coordinates system related to the observations of small planets was suggested by B.V.Numerov. Astronomers of Mykolaiv Astronomical Observatory participated in the international part of this project (AGK3R-catalogue). The Poltava gravimetric observatory was founded by A.Ya.Orlov in 1926 to construct a gravity map of the territory of Ukraine and to establish astrometric research, earth tides, and Latitude Service with zenith-telescopes. The main research fields of the Main Astronomical Observatory of the NAS of Ukraine, founded by A.Ya.Orlov in 1944, were related to the positional and photographic astrometry during the first decade of its work. We defined three “genealogical scientific trees” of astrometric schools. Two of them were formed under the leadership of outstanding personalities of the XX century: Prof. Alexander Ya. Orlov (the founder and first director of the Observatory, 1944–1948, 1950–1951), who moved to Kyiv from Poltava, and Prof. Avenir A.Yakovkin (director of the Observatory in 1952–1959), who moved to Kyiv from Kazan. The third genealogical tree has grown from the Pulkovo astronomical school. Formation of main directions of scientific researches and its transformation are also discussed. Keywords: astrometric research, positional astrometry, photographic astrometry, fundamental astrometry.

Determination of the Absolute Intensities of Spectral Lines of the 12С2H4 Molecule

2018 ◽  
Vol 61 (6) ◽  
pp. 1074-1078
Author(s):  
Yu. S. Aslapovskaya ◽  
N. I. Raspopova
Keyword(s):  
Spectral Lines ◽  
Absolute Intensities ◽  
The Absolute

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

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