19 research outputs found
Ultra high IP3 passive GaAs FET mixers
This paper describes single-balanced passive GaAs FET mixers with different balancing principles for the lower GHz range. The mixers achieve conversion losses of about 7 dB and input third-order intercept points (IIP3) of up to 44 dBm. Port isolation values of more than 70 dB have been achieved. Different balancing topologies, design process and results are being discussed
Mineralisation of distinct biogas digestate qualities directly after application to soil
Biogas is an important energy source produced by the anaerobic fermentation of raw faecal slurries and plant residues. Separation
of the total digestate increases the fertilizer quality of the liquid fraction and the carbon sequestration potential of the solid
fraction. A 12-day incubation study was carried out to investigate the relationships between the chemical composition of different
digestate qualities and the immediate response of soil microbial activity and biomass indices. The highest cumulative (\u3a3) CO2-C
efflux was observed after adding the solid fraction and lowest after adding the liquid fraction to soil, which was even lower than
that of the control. The \u3a3CO2-C efflux showed the strongest negative correlation with the raw ash and strong positive correlations
with the raw fibre concentration and the C/N ratio of the different digestate qualities. The highest and similar \u3a3N2O-N efflux was
observed after adding the total digestate or the liquid fraction, which were equivalent to approximately 1% of added N. This
relatively low percentage indicates a possible origin from nitrifier denitrification. Total digestate and its liquid fraction exhibited
considerable net-N mineralisation rates, which could mainly be predicted by the C/N ratios of the different digestate qualities.
Microbial biomass C did not respond to the application of any digestate quality, whereas the fungal ergosterol content increased
after applying the solid and the composted solid fractions. This raw fibre\u2013induced fungal growth led to strong net-N immobilisation
in soil after applying these two digestate qualities
Mineralisation of distinct biogas digestate qualities directly after application to soil
Gefördert im Rahmen des Projekts DEA