Search

The parameters of the synthesis of catalysts by the solution combustion method using oxalic acid as a reducing agent were investigated. The activity of the catalysts was determined in the production of hydrogen and carbon nanofibers by the catalytic decomposition of methane. The efficiency of oxalic acid was demonstrated in the preparation of a nickel catalyst (90% Ni/10% Al2O3), which does not require the preliminary reduction with hydrogen. Regression analysis identified that the yields of carbon and hydrogen are most strongly affected by temperature among other synthesis parameters. [ABSTRACT FROM AUTHOR]

The electrical conductivity of carbon nanofiber–thermally expanded graphite compacted systems at various component mass ratios was investigated. Because the initial carbon nanofibers were not pressed, thermally expanded graphite was added as a binder. The compaction was carried out at a pressure of 11 MPa for 30 min. The AC electrical conductivity was measured in a variable-field frequency range of 25 Hz to 1 MHz during heating from 30 to 100°C. It was found that a decrease in the binder content leads to a narrowing of the electrical conductivity range of the system. [ABSTRACT FROM AUTHOR]

• Solution combustion Ni/Al 2 O 3 catalysts for CO x -free hydrogen production. • Potassium content changes the phase composition of resulting catalysts. • Potassium is electronic promoter of nickel, inhibiting the growth of particle size. • Catalysts demonstrated the highest hydrogen yield at 675 and 750 °C. A set of catalysts containing 0.25–10 wt% K 2 O was prepared by solution combustion synthesis. The catalytic systems were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and low-temperature nitrogen adsorption. The catalytic methane decomposition was carried out at 0.5 MPa, 100 L CH4 /(h·g cat), and temperature ranging from 550 to 750 °C. It has been found that varying the potassium content led to a change in the phase composition and textural characteristics of the resulting catalysts. The introduction of potassium (0.25 wt% K 2 O) into the nickel catalyst made it possible to change the particle size distribution towards the formation of smaller particles, from 5 to 30 nm to 5–10 nm, promoting the formation of higher yield of H 2. The Ni-0.25 %K 2 O/Al 2 O 3 и Ni-1 %K 2 O/Al 2 O 3 catalysts demonstrated the highest hydrogen yield of 11.6 g/g cat and 17.0 g/g cat with a maximum at 675 and 750 °C, respectively. The highest yield of carbon material (51.0 g/g cat) was obtained over Ni-1 %K 2 O/Al 2 O 3 catalyst. [ABSTRACT FROM AUTHOR]

In the present study, we investigate the biological properties and genomic organization of virulent bacteriophage AM24, which specifically infects multidrug-resistant clinical Acinetobacter baumannii strains with a K9 capsular polysaccharide structure. The phage was identified as a member of the family Myoviridae by transmission electron microscopy. The AM24 linear double-stranded DNA genome of 97,177 bp contains 167 open reading frames. Putative functions were assigned for products of 40 predicted genes, including proteins involved in nucleotide metabolism and DNA replication, packaging of DNA into the capsid, phage assembly and structural proteins, and bacterial cell lysis. The gene encoding the tailspike, which possesses depolymerase activity towards the corresponding capsular polysaccharides, is situated in the phage genome outside of the structural module, upstream of the genes responsible for packaging of DNA into the capsid. The data on characterization of depolymerase-carrying phage AM24 contributes to our knowledge of the diversity of viruses infecting different capsular types of A. baumannii. [ABSTRACT FROM AUTHOR]

The characteristics of thermal electrets based on epoxy resins were adjusted by varying curing agent and filler contents. The addition of carbon nanotubes (MWNT-1020) reduced the electret characteristics of the epoxy composites due to a higher electrical conductivity and improved the mechanical properties of the epoxy composites. [ABSTRACT FROM AUTHOR]