The paper estimates the household labor earning process using the March Current Population Survey 1968–2011. GMM estimates confirm that the results in Storesletten et al. (2004) still hold in a much larger data set over a longer period. The persistent idiosyncratic risk is strongly countercyclical, with an annual auto-correlation equal to .973 and an standard deviation that increases by 72.5% (from .090 to .156) as the macroeconomy moves from peak to trough.
Polycaprolactone (PCL) was used as both carbon source and biofilm support for denitrifying bacteria in a packed-bed bioreactor. The denitrification performance and microbial diversity were investigated. The microbial community of biofilm developed on the surface of PCL in the reactor was analyzed by pyrosequencing method. The experimental results showed the average nitrate removal efficiency reached 93 % at stable operation. ESEM observation and FTIR analysis were conducted to characterize the PCL structure before and after microbial utilization. For the microbial community, Betaproteobacteria predominated, and most of the PCL-degrading denitrifying bacteria assigned to the family of Comamonadacea. Denitrifying bacteria accounted for more than 20 % in the total population, indicating that PCL is a good carrier and carbon source for biological denitrification.
Biodegradable polymer was used as carbon source and biofilm support for nitrate removal from aqueous solution as an attractive alternative for biological denitrification. The objective of this paper was to investigate the denitrification performance and microbial community of a packed-bed bioreactor using poly (butanediol succinate) (PBS), a biodegradable polymer, as carbon source and biofilm support. NO3-N concentration was determined by UV spectrophotometer. NO2-N concentration was assayed by hydrochloric acid naphthyl ethylenediamine spectrophotometry method. Total organic carbon (TOC) was measured using a TOC analyzer. The morphology of the samples was observed using an environmental scanning electron microscope (ESEM). The microbial community was analyzed by pyrosequencing method. The experimental results showed that an average removal efficiency of nitrate was 95 %. ESEM observation and FTIR analysis indicated the changes of PBS granules before and after microbial utilization. Pyrosequencing results showed that Betaproteobacteria predominated, and most of PBS-degrading denitrifying bacteria were assigned to the family Comamonadaceae. Denitrifying bacteria accounted for 13.02 % in total population. The PBS granules were suitable support and carbon source for denitrifying bacteria.
This paper presents a dual-band rectifying circuit for wireless power transmission working at 2.45 GHz and 5.8 GHz. A modified dual-band matching network is adopted to realize the highly efficient dual-band rectifier. Source-pull simulations are performed, to determine the proper impedances at the two different frequencies. The proposed dual-band rectifier has been implemented and the measurements show good agreement with simulation. With a dual-band input matching network, the measurement results for an input power level of 10 mW show peak RF-to-DC efficiencies of 66.8 % and 51.5 % at 2.45 GHz and 5.8 GHz respectively.