http://dspace.nbuv.gov.ua:80/handle/123456789/114717 2026-04-13T04:03:04Z 2026-04-13T04:03:04Z Tsvirko, M. Tkaczyk, S. Kozak, M. Kalota, B. http://dspace.nbuv.gov.ua:80/handle/123456789/119962 2017-06-11T00:04:28Z 2013-01-01T00:00:00Z

Luminescent temperature sensor based on [Ru(bpy)₃]²⁺ incorporated into chitosan Tsvirko, M.; Tkaczyk, S.; Kozak, M.; Kalota, B. A novel luminescent temperature sensor using ruthenium(II)-tris(2,2´-bipyridil) ([Ru(bpy)₃]²⁺) incorporated into chitosan polymer matrix was developed. The sensor exhibits completely reversible and stable luminescent response (λ exc = 455 nm, λ em = 605 nm), strong temperature sensitivity (–2.0 %/°C), significant luminescence intensity decrease (~10×) in the range of 25–75°C, and stable construction. Ruthenium(II) complex oxygen sensitivity was avoided by use of matrix (chitosan) with low oxygen permeability coefficient. In the absence of oxygen the sensor shows a little higher accuracy and stability of luminescence response than under oxygen conditions. Moreover, this sensor, due to biocompatibility of the used ingredients and the emission in the red VIS-region, which is transparent for tissues, is promising for use in biological applications.

2013-01-01T00:00:00Z Kanishchev, V.N. http://dspace.nbuv.gov.ua:80/handle/123456789/119910 2017-06-11T00:03:35Z 2013-01-01T00:00:00Z

The increase of crystal growing rate without damaging the smoothness of interface border Kanishchev, V.N. This paper provides literature data on non-stationary crystallization of binary melt, making it possible to put forward a hypothesis about a fluctuation mechanism of the structure transitions on the interface surface. Another argument for this hypothesis is the authors' observation results of the front crystallization at growing a sapphire crystal by horizontal directed crystallization. It has been suggested that it will be possible to grow crystals with a smooth interface border faster at a variable rate of crystallization rather than at a constant one.

2013-01-01T00:00:00Z Belikov, K.N. Sofronova, E.M. Matejchenko, P.V. Babayevskaya, N.V. Sofronov, D.S. http://dspace.nbuv.gov.ua:80/handle/123456789/119909 2017-06-11T00:03:57Z 2013-01-01T00:00:00Z

Production of disperse particles of CdS from thiourea solutions in the presence of amino acids Belikov, K.N.; Sofronova, E.M.; Matejchenko, P.V.; Babayevskaya, N.V.; Sofronov, D.S. Synthesis of fine-dispersed particles of CdS by precipitation from thiourea solutions in the presence of different amino acids is carried out. It is found that the presence of ε aminocapronic, glutamic and n-aminobenzoic acids leads to the formation of small lamellar particles. Introduction of n-aminobenzoic acid in reaction mixture allows to increase a specific surface by 30 times.

2013-01-01T00:00:00Z Golovina, I.S. Bryksa, V.P. Strelchuk, V.V. Geifman, I.N. http://dspace.nbuv.gov.ua:80/handle/123456789/119908 2017-06-11T00:03:04Z 2013-01-01T00:00:00Z

Phase transitions in the nanopowders KTa₀.₅Nb₀.₅O₃ studied by Raman spectroscopy Golovina, I.S.; Bryksa, V.P.; Strelchuk, V.V.; Geifman, I.N. Raman spectra of KTa₀.₅Nb₀.₅O₃ nanopowder solid solution were obtained at the temperatures from –190°C to 600°C and investigated for the first time. The compound was synthesized by a new technology. Temperature dependences of the intensity, width and frequency of the B₁(TO₂), A₁(TO₁), B₁(TO₃), A₁(TO₃) and B₂(TO₃) modes are thoroughly analyzed. A significant expanding of the temperature ranges of all phase transitions, correlated with a spread of particle sizes is registered. It was found that an average temperature of each of the phase transitions is shifted in different way, in particular: a low-temperature transition at 30 degrees higher, the middle transition at 10 degrees higher, and the ferroelectric phase transition occurs at 20 degrees lower than the temperature of the corresponding transitions in single-crystal KTa₀.₅Nb₀.₅O₃.

2013-01-01T00:00:00Z