Electrical properties of compacted carbon nanomaterials

In this paper, the electrical properties of various compacted carbon nanomaterials were investigated. Compacted carbon nanomaterials (carbon nanofibers, multi-walled carbon nanotubes) were compacted into cylindrical samples and the electrical properties were measured in a frequency range from 50 Hz to 1MHz

Solubility of Helium in Ice Ih at Pressures up to 2000 bar: Experiment and Calculations

The solubility of helium in ice Ih has been examined both experimentally and theoretically. It has been demonstrated that the calculations are in good accord with the experimental data. The tested calculation method has been used for deriving the helium solubility in ice Ih at pressures up to 2000 bar and at temperatures of 0–50 °C. Obtained data may be useful in some practical applications (storage of enriched with helium natural gas in permafrost, extraction of helium from natural gas)

Turning cellulose waste into electricity: hydrogen conversion by a hydrogenase electrode.

Hydrogen-producing thermophilic cellulolytic microorganisms were isolated from cow faeces. Rates of cellulose hydrolysis and hydrogen formation were 0.2 mM L(-1) h(-1) and 1 mM L(-1) h(-1), respectively. An enzymatic fuel cell (EFC) with a hydrogenase anode was used to oxidise hydrogen produced in a microbial bioreactor. The hydrogenase electrode was exposed for 38 days (912 h) to a thermophilic fermentation medium. The hydrogenase activity remaining after continuous operation under load was 73% of the initial value

Electrical properties of epoxy composites based on carbon black

In this work, AC electrical properties of epoxy composites based on carbon black (CB) were determined depending on the loading of filler. The measurements were carried out within a frequency range 20 Hz – 1 MHz. The loading of carbon black was 0–5 wt.% in composites. The conductivity increased when increasing the content of carbon black and the maximum values were observed at 5 wt.% CB. The maximum value of permittivity was at 0.75 wt.% CB and it can be considered as percolation threshold

Electron micrograph of the cellulose.

<p><b>T</b>he isolated microorganisms immersed in exopolysaccharide matrix on the surface of cellulosic fibers (7 days of cultivation).</p

Dynamic of changes in the open circuit potential values.

<p>The cultivation time of hydrogen-producing bacteria in the bioreactor cell was 25 days (overpressure in the bioreactor – 0.5 atm, pH 6.7–7.0, 60 °C).</p

Hydrogen production by the selected microbial consortium using different types of substrates.

<p>1 – glossy white paper; 2 – glossy paper with print; 3 – glossy colour printed paper; 4 – white newsprint paper; 5 – newsprint with print; 6 – colour newsprint paper; 7 – wheat bran; 8 – kitchen waste; 9 – grains; 10 – yeast; 11 – wood sawdust; 12 – straw; 13 – pretreated filter paper; 14 – filter paper. The cultivation time was 7 days.</p

Scheme of the developed bioreactor cell.

<p>MPDBP - pyrrole derivative N-methyl-N’-(12-pyrrol-1-yldodecyl)-4,4’-bipyridinium ditetrafluoroborate.</p

Electron micrograph of the cellulose.

<p>The initial stage of cellulose colonisation by isolated microorganisms (3 days of cultivation).</p

Dependence of power output on overvoltage of the oxygen-hydrogen fuel cell combined with a bioreactor.

<p>The cultivation time of hydrogen-producing bacteria in the bioreactor cell was 38 days (25th day – black curve; 29th day – red curve; 34th day – green curve; 38th day – yellow curve, overpressure in the bioreactor – 0.5 atm, pH 6.7–7.0, 60 °C).</p