0000000000303305
AUTHOR
Volodymyr Savchyn
Modification of Polymer-Magnetic Nanoparticles by Luminescent and Conducting Substances
The polymer encapsulated magnetic nanoparticles were obtained by suspension polymerization of styrene in the aqueous dispersion of magnetite. Functionalization of capsules was carried out by adsorp...
Luminescence, vibrational and XANES studies of AlN nanomaterials
Abstract The paper reports comparative studies on synthesized aluminium nitride nanotubes, nanoparticles and commercially available micron-sized AlN powder using different spectroscopic techniques: cathodoluminescence measurements (CL), X-ray absorption near edge spectroscopy (XANES) and Fourier-transform infrared spectroscopy (FTIR). Crucial distinctions in CL spectra are observed for nano- and microsized aluminium nitride powders; systematic shift of the IR absorption maximum has been detected for nanostructured aluminium nitride as compared to commercial samples. Through XANES experiments on Al K-edge structural differences between nano- and bulk AlN are revealed, intensity of features i…
Combustion Formation of Novel Nanomaterials: Synthesis and Cathodoluminescence of Silicon Carbide Nanowires
This paper presents the combustion synthesis and characterization of one-dimensional silicon carbide nanostructures (nanowires of 3C-SiC polytype with zincblend structure) by means of cathodoluminescence technique. Cathodoluminescence spectra of nano-SiC samples and, as a reference, of a commercially available SiC micropowder are compared. It is shown that the emission band at 1.97 eV which is slightly evidenced in the spectrum of the commercial SiC under 10 keV electron beam irradiation becomes the prevailing band in CL of the purified silicon carbide nanowires.
Silicon carbide nanowires: synthesis and cathodoluminescence
Silicon carbide nanowires have been synthesized via a combustion synthesis route. Structural studies showed that obtained SiC nanowires belong dominantly to 3C polytype with zinc-blend structure. Cathodoluminescence spectra from these nanostructures within the temperature range of 77...300 K, show obvious differences with respect to the bulk materials. The exciton band of the bulk 3C-SiC is significantly damped and the prevailing line is found to be at 1.99 eV (77 K), proving the key role of defect centers in optical properties of the investigated nanomaterial.
Old Growth Forests in the Ukrainian Carpathians: Criteria and Indicators, identification methodology, and results up-to date
Historically, identification and conservation of OGF remnants in the region has undergone several stages: - 2006-10 – pilot application of the OGF concept within the High Conservation Value Forests identification (FSC certification mainly); - 2008-12 – pilot field works on the Old-Growth Forests (OGF) identification in Ukrainian Carpathians; - 2012 – harmonized C&I for OGF identification in Maramuresh part of the Carpathians (RO / UA) developed, - 2012 - now – large-scale field identification; - 2014 – the OGF C&I above used as a basis for the Virgin Forest C&I by the Carpathian Convention, see: http://www.carpathianconvention.org/tl_files/carpathiancon/Downloads/03%20Meetings%2…