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Klym H.,Lviv Polytechnic | Ingram A.,Opole University of Technology | Shpotyuk O.,Vlokh Institute of Physical Optics | Shpotyuk O.,Jan Dlugosz University in Czestochowa | And 2 more authors.
Nanoscale Research Letters

The water-vapor sorption processes in nanoporous MgO-Al2O3 ceramics are studied with positron annihilation lifetime (PAL) spectroscopy employing positron trapping and positronium (Ps)-decaying modes. It is demonstrated that the longest-lived components in the four-term reconstructed PAL spectra with characteristic lifetimes near 2 and 60–70 ns can be, respectively, attributed to ortho-positronium (o-Ps) traps in nanopores with 0.3- and 1.5–1.8-nm radii. The first o-Ps decaying process includes “pick-off” annihilation in the “bubbles” of liquid water, while the second is based on o-Ps interaction with physisorbed water molecules at the walls of the pores. In addition, the water vapor modifies structural defects located at the grain boundaries in a vicinity of pores, this process being accompanied by void fragmentation during water adsorption and agglomeration during water desorption after drying. © 2016, Klym et al. Source

Klym H.,Lviv Polytechnic | Balitska V.,Lviv Institute of Materials | Balitska V.,Lviv State University of Life Safety | Shpotyuk O.,Lviv Institute of Materials | And 2 more authors.
Microelectronics Reliability

The mathematical models of thermally-induced degradation processes in solids with nano- and microscale topological disordering - bulk and thick-film ceramic composites based on mixed transition-metal manganites are considered. It was shown that degradation transformations in these materials are best described by stretched or suppressed exponential relaxation function. The stretched exponential degradation kinetics is proper to own degradation transformations in such one-type systems as bulk ceramics and multilayered thick-film structures. The mechanism of degradation transformations in one-layered thick films, including two or more different on their origin elementary are described by suppressed exponential kinetics. © 2014 Elsevier Ltd. All right reserved. Source

Klym H.,Lviv Polytechnic | Hadzaman I.,Drohobych State Pedagogical University | Yurchak I.,Lviv Polytechnic
Proceedings of the 21st International Conference on Mixed Design of Integrated Circuits and Systems, MIXDES 2014

The temperature sensitive thick-film structures in different design of sensitive layers and separate temperature and humidity sensitive thick-film systems based on spinel-type NiMn2O4-CuMn 2O4-MnCo2O4 manganites with p- and p+-types of electrical conductivity and insulating magnesium aluminate MgAl2O4 were prepared. Taking into account good properties of obtained elements, they can be applied for microelectronics application and as multifunctional integrated sensors for effective monitoring and control. © 2014 Department of Microelectronics and Computer Science. Source

Klym H.I.,Scientific Research Company carat | Klym H.I.,Lviv Polytechnic | Hadzaman I.V.,Scientific Research Company carat | Hadzaman I.V.,Drohobych State Pedagogical University | And 2 more authors.
Proceedings - 10th International Conference on Laser and Fiber-Optical Networks Modeling, LFNM 2010

Temperature and humidity-sensitive thick-film structures based on spinel semiconducting ceramics different chemical composition (Cu0.1Ni 0.1Co1.6Mn1.2O4 and Cu 0.1Ni0.8Co0.2Mn1.9O4) and dielectric magnesium aluminate MgAl2O4 ceramics were fabricated and studied. These elements are shown to be successfully applied for integrated temperature/humidity sensors of environmental monitoring and control. © 2010 IEEE. Source

Chernets M.V.,Drohobych State Pedagogical University | Chernets M.V.,Lublin University of Technology
Journal of Friction and Wear

Using a generalized cumulative wear model, the tribocontact problem has been solved for a sliding bearing, the shaft of which has small contour lobing with various forms. The effect of lobing on the bearing life has been investigated at the complete single-area and mixed-area contact. It has been found that the ovality and trilobing of the shaft promote a rise in the service life. Features of this effect are presented graphically. © 2015, Allerton Press, Inc. Source

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