Influence of temperature and glass composition on aluminum nitride contact angle

Results of research of different glass compositions for possibility of their application in metallization pastes intended for ceramics based on aluminum nitride are presented in this article. It includes research of contact angle of aluminum nitride with glasses of different compositions at different temperatures and different roughness of ceramics

Influence of dispersion state of initial AlN powder on the hydrolysis process in air environment

The research results of the hydrolysis processes of aluminum nitride powders received by the SVS method in dependence on humidity of the storage environment, and grain size distribution are presented in this work. Oxidation kinetics was estimated by means of X- ray Diffraction (XRD) and scanning electron microscopy (SEM). The induction period of the hydrolysis process for various powders, its dependence on powder dispersion and thickness of the oxide layer on surface of particles have been defined

Influence of dispersion state of initial AlN powder on the hydrolysis process in air environment

The research results of the hydrolysis processes of aluminum nitride powders received by the SVS method in dependence on humidity of the storage environment, and grain size distribution are presented in this work. Oxidation kinetics was estimated by means of X- ray Diffraction (XRD) and scanning electron microscopy (SEM). The induction period of the hydrolysis process for various powders, its dependence on powder dispersion and thickness of the oxide layer on surface of particles have been defined

Kinetics of thermal destruction of highly porous anionexchange resin TOKEM-320Y

Temperature characteristics, stages and thermal effects of the processes occurring during the thermolysis of TOKEM-320Y anion-exchange resin in an atmosphere of air were determined by differential thermal analysis. The activation energies and the orders of reactions of thermal decomposition of the resin were calculated by the Kissinger and Metzger-Horowitz methods using the TG curves obtained at different heating rates of the resin. Models are proposed that most accurately describe the decomposition of TOKEM-320Y in air in the temperature range 25-800 °C

Fires and Clear-Cuttings as Local Areas of Arthropod Diversity in Polar Regions: Khibiny Mountains

The well-known phenomenon of attracting untypical animals to disturbed territories has been poorly investigated in the polar mountains. We studied arthropod diversity in self-healing industrial clear-cuts and burn areas in the Khibiny Mountains, Kola Polar region. Fieldworks were conducted at four sites, including a control mountain taiga forest and its three transformed variants: burnt forest, uncleared clear-cut, and twice-disturbed burnt clear-cut. Arthropods were collected using formalin traps 2–3, 5–6, and 8–9 years after industrial deforestation in 2012 and an extensive grass-roots fire in 2013. Out of 124 identified species (spiders—61; ground beetles—41; and rove beetles—22), 79 (or 64%) were collected in disturbed, primarily burned areas and were absent in control forest. We note ten species of rove beetles, nine species of ground beetles, and eight species of spiders for the first time in the well-studied arthropod fauna of the Khibiny Mts. We found that grass-root fires transform the soil vegetation covers in the polar mountain forests more powerfully in comparison with extensive deforestation and attract a greater diversity of arthropods with different preferences, enriching the fauna of the polar mountains and the Subarctic region as a whole. The attraction effect persists for, at least, a decade after the violations

Synthesis of nanostructured composite materials of MoO3/TiO2–SiO2 with spherical shape prepared with resin

The aim of this work was to synthesize of nanostructured MoO3/TiO2–SiO2 composites with hollow spherical shape by thermal decomposition of anion exchangers saturated with Mo7O6 24 ions and treated with the TBT–TEOS sol. The effect of the kinetics (Kissinger and the Metzger-Horowitz methods) of thermal decomposition of resins of porous and gel structures on the size of MoO3 nanoparticles and the strength of MoO3/TiO2–SiO2 spheres was shown. The formation of dense spherical nanostructured agglomerates of the composite is facilitated by reactions occurring at the interface between the phases of cylindrical and spherical symmetry when using an anion exchange resin with a porous structure. The decomposition reactions of the anion-exchange resin of the gel structure, accompanied by random nucleation, lead to the formation of hollow spherical agglomerates of the composite with cracks on the surface. The materials were characterized by DSC–TGA, XRD and SEM

Fabrication of MoO3/TiO2-SiO2 with hollow spherical shape using resin as the template: Effect of decomposition of resins

Anion exchange resins are widely used in template synthesis of oxide composites. The present work is aimed to study the thermal destruction of anion exchangers with divinyl-benzene and polyacrylate matrices in order to obtain hollow spherical MoO3/TiO2–SiO2 composites from these resins preliminarily saturated with paramolybate ion and coated with tetrabutoxytitanium sol with tetroethoxysilane. It is shown that the processes of resins decomposition affect the strength of spherical composites. Decomposition of the resin with a polyacrylate matrix, accompanied by random nucleation and burnout of the organic matrix at 350C, leads to the formation of spherical oxide composites with cracks on the surface. The decomposition reactions of the resin with a divinylbenzene matrix occurring at the boundaries of the phases of cylindrical and spherical symmetry, as well as a lower burnout temperature of the organic matrix (290C), contribute to the formation of dense MoO3/TiO2–SiO2 spheres. Hollow spherical composites 0.3–0.5 mm in size are orthorhombic α-MoO3 coated with a mixture of titanium dioxide with anatase structure and amorphous silicon dioxid