The macrokinetic features of combustion in the Ta-Zr-B system were studied. Combustion is characterized by spin mode, suggesting the limiting role of gas-phase mass transfer of reagents. The mechanism of chemical reactions and phase formation in combustion wave was discussed. Primary layers of t...

Almost full density (>99% theoretical density (ρth)) was achieved for ZrB2-20vol% SiC-Xwt.% Ta (X = 2,5, 5 and 10) composites after Spark Plasma Sintering (SPS) (Temperature: 1900 °C, Pressure: 50 MPa; Time: 3 min). The microstructure of ZrB2-based composites exhibited core-rim structure and i...

This paper describes a model developed to simulate the evolution of carbide layers (TaC/Ta2C) formed during carburizing and annealing treatments of tantalum. The model is based on a parabolic evolution of the layer thickness during the growth, and on the carbon conservation during the annealing....

On the basis of the evolutionary methodology for crystal structure prediction, we have revealed a novel monoclinic C2/m structure TaB4 with planar six-membered ring boron network along the crystallographic b axis. We name it as m-TaB4. The calculations of elastic constants and phonon dispersion ...

The chemical-physical properties of thin lanthanum (oxy)boride films deposited on polycrystalline tantalum substrates by different deposition techniques (Pulsed Laser Deposition - PLD - with either nanosecond or femtosecond laser source, and electron beam evaporation) were compared in order to i...

The new ternary transition metal-rich borides Ta2OsB2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositio...

Niobium boride powders having NbB, NbB2 and Nb3B4 phases in various amounts and single phase NbB powders were successfully synthesized by using powder metallurgy methods from related metal oxide raw materials in the presence of a strong reducing agent. Nb2O5, B2O3 and Mg powder blends were mille...

Manganese oxide/titanium dioxide (MnOx/TiO2, or MnTi) catalyst prepared by an ultrasound-assisted impregnation method was employed for simultaneous nitrogen oxide (NO) reduction and elemental mercury (Hg0) oxidation under a simulated selective catalytic reduction (SCR) atmosphere. An NO reductio...

Copper slag is a byproduct of the pyrometallurgical smelting of copper concentrate. It was used in this study to catalyze elemental mercury (Hg0) oxidation in simulated coal combustion flue gas. The copper slag exhibited excellent catalytic performance in Hg0 oxidation at temperatures between 20...

The selective catalytic reduction (SCR) system for NOX removal in coal-fired power plants has a promoting effect on the oxidation and removal of elemental mercury. In this study, basic mechanism of mercury oxidation by V2O5-based SCR catalyst is investigated via density functional theory method ...

Fe2O3 is one of the catalytically active compositions present in fly ash for mercury oxidation. Fe2O3 sample was prepared by a precipitation method. The textural property and surface chemical state of Fe2O3 sample were characterized by Brunauer-Emmett-Teller (BET) surface area and X-ray photoele...

The mercury speciation and concentration in flue gas before and after selective catalytic reduction (SCR) system of a 300MW coal-fired utility boiler has been determined using Ontario Hydro method (OHM). The effect of SCR catalyst on mercury speciation transformation is investigated and the impa...

Commercial vanadium-titanium-based selective catalytic reduction (SCR) catalyst exhibits a certain ability for mercury removal during the denitrification process of coal-fired flue gas. WO3 is an important additive agent for SCR catalyst, yet few studies have been reported on the role of WO3 dur...

Manganese oxide octahedral molecular sieve (OMS-2) with cryptomelane structure synthesized by a solvent-free method was employed to oxidize gaseous elemental mercury (Hg0) in coal combustion flue gas for the first time. Brunauer-Emmett-Teller (BET) surface area analysis, X-ray diffraction (XRD),...

Periodic DFT computational studies are applied to investigate mercury adsorption and oxidation mechanism over RuO2 catalyst. The adsorption of mercury species (Hg0, HgCl, HgCl2) and HCl on RuO2(1 1 0) surface were obtained. The results indicate that all the mercury species have strong interactio...

Transformation of metallic mercury (Hg°) to mercuric ion (Hg2+) in hydrosphere is the entrance of mercury cycle in water environments and leads to toxicological impact of serious global concern. Two yeast strains of Yarrowia (Idd1 and Idd2) isolated from Hg-contaminated sediments were studied f...

In order to evaluate the influence of acoustic phonon scattering on electron mobility in β -Ga2O3, electronic structure and transport properties were analyzed under the frame of deformation potential and relaxation time approximation. First-principles calculations were carried out, to calculate...

Soybean oil-based silanized factice (SF) was prepared and its compatibility with styrene butadiene rubber (SBR)/silica composite was evaluated. Characterization of SF, obtained by the inter-mixing of soybean oil (SBO), sulfur and bis-(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT) with curing a...

A novel process was proposed for preparing titanium dioxide by the decomposition of titanium slag in sodium hydroxide system under atmospheric pressure. The kinetics on the decomposition of titanium slag was mainly investigated. The results on effect of reaction temperature, particle size and Na...

The formation of organic poisoning intermediate species during fuel (alcohol) oxidation over a noble-metal catalyst electrode retards the electrooxidation reaction. To address this problem, we report the synthesis of a manganese-titanium-oxide-hydroxide-supported palladium nanocatalyst ([email p...