Time filter

Source Type

Ryzhikov V.D.,Institute for Scintillation Materials of Ukraine | Naydenov S.V.,Institute for Single Crystals | Opolonin O.D.,Institute for Scintillation Materials of Ukraine | Volkov V.G.,Institute for Scintillation Materials of Ukraine | Smith C.F.,Naval Postgraduate School, Monterey
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2016

This work has been dedicated to the search for a new possibility to use multi-energy digital radiography (MER) for medical applications. Our work has included both theoretical and experimental investigations of 2-energy (2E) and 3- energy (3Crossed D sign•) radiography for imaging the structure of biological objects. Using special simulation methods and digital analysis based on the X-ray interaction energy dependence for each element of importance to medical applications in the X-ray range of energy up to 150 keV, we have implemented a quasi-linear approximation for the energy dependence of the X-ray linear mass absorption coefficient μm (E) that permits us to determine the intrinsic structure of the biological objects. Our measurements utilize multiple X-ray tube voltages (50, 100, and 150 kV) with Al and Cu filters of different thicknesses to achieve 3-energy X-ray examination of objects. By doing so, we are able to achieve significantly improved imaging quality of the structure of the subject biological objects. To reconstruct and visualize the final images, we use both two-dimensional (2D) and three-dimensional (3D) palettes of identification. The result is a 2E and/or 3E representation of the object with color coding of each pixel according to the data outputs. Following the experimental measurements and post-processing, we produce a 3Crossed D sign• image of the biological object - in the case of our trials, fragments or parts of chicken and Turkey. © 2016 SPIE.

Lisitsyn V.M.,Tomsk Polytechnic University | Valiev D.T.,Tomsk Polytechnic University | Tupitsyna I.A.,Institute for Scintillation Materials of Ukraine | Polisadova E.F.,Institute for Scintillation Materials of Ukraine | And 5 more authors.
Journal of Luminescence | Year: 2014

We investigated pulsed photoluminescence and pulsed cathodoluminescence in ZnWO4 crystals and composite materials based on dispersed powders of zinc tungstate in the polymer matrix. It is shown that the size of crystal particles affects the luminescence decay time in excitation by electron and laser radiation. The decay time obtained for the composite material with nanoparticles 25 nm and 100 nm in size is equal to 5 μs and 7 μs, respectively. Relative values of the light yield of composite containing zinc tungstate crystals in the form of rods are found to be larger in comparison with crystallites in the form of grains. The mechanisms of luminescence recombination in laser and electron excitation are discussed. © 2014 Elsevier B.V.

Kolos N.N.,University of Kharkiv | Kovalenko L.U.,University of Kharkiv | Borovskoy V.A.,Institute for Single Crystals
Chemistry of Heterocyclic Compounds | Year: 2011

Dihydro derivatives of pyrazolo[3,4-b]pyridine-, pyrazolo[1,5-a]pyrimidine- , and [1,2,4]triazolo-[1,5-a]pyrimidinecarboxylates have been prepared by cyclocondensation of β-aroylacrylates with 5-aminopyrazoles and 3-amino-1,2,4-triazole. Heating dihydro[1,2,4]triazolo[1,5-a]pyrimidine-7- carboxylates with hydrazine hydrate led to recyclization of the pyrimidine ring to form 6-arylpyridazin-3(2H)-ones. © 2011 Springer Science+Business Media, Inc.

Fedorov A.,Institute for Scintillation Materials of Ukraine | Gektin A.,Institute for Scintillation Materials of Ukraine | Lebedynskiy A.,Institute for Scintillation Materials of Ukraine | Mateychenko P.,Institute for Single Crystals | Shkoropatenko A.,Institute for Scintillation Materials of Ukraine
Radiation Measurements | Year: 2013

500 mkm thick CsI:Tl columnar films can be produced using thermal evaporation in vacuum by sublimation of the same bulk crystal. Comparison of afterglow and radiation stability of deposited CsI:Tl films with source crystal was the aim of current work. It is shown that the afterglow in the films is always below its level in initial single crystal. It was ascertained that the annealing atmospheres influence the processes leading to the activator depletion of the films during the thermal processing. © 2013 Elsevier Ltd. All rights reserved.

Fedorov A.,Institute for Scintillating Materials | Lebedinsky A.,Institute for Scintillating Materials | Mateychenko P.,Institute for Single Crystals
Journal of Crystal Growth | Year: 2011

The dewetting behavior of vacuum deposited CsI films on LiF (1 0 0) oriented substrate was observed. Rupture of initially continuous solid films occurs in a duration of monthsminutes, depending on film thickness. Finally, spherical particles are formed on the substrate. The particles possess a pronounced orientation in the <1 1 0> direction normal to the substrate surface. This effect has been attributed to the difference between surface energy values of the film and substrate, and the interface energy according to Young's equation. The corresponding values of surface energy have been calculated and have confirmed the nature of the observed effect. © 2010 Elsevier B.V. All rights reserved.

Discover hidden collaborations