This study investigated the cotransport of titanium dioxide nanoparticles (nTiO(2)) and fullerene nanoparticles (nC(60)), two of the most widely utilized nanoparticles, in saturated quartz sand under a series of ionic strengths in NaCl solutions (0.1-10 mM) at both pH 5 and 7. Under all examined ionic strengths at pH 5, both breakthrough h curves and retained profiles of nTiO(2) in the copresence of nC(60) were similar to those without nC(60), indicating that nC(60) nanoparticles copresent in suspensions did not significantly affect the transport and retention of nTiO(2) in quartz sand at pH 5. In contrast, under all examined ionic strengths at pH 7, the breakthrough curves of nTiO(2) in the copresence of nC(60) in suspensions were higher and the retained profiles were lower than those without nC(60), which demonstrated that the presence of nC(60) in suspensions increased the rate of transport (decreased retention) of nTiO(2) in quartz sand at pH 7 Competition of deposition sites on quartz sand surfaces by the copresence of nC(60) was found to contribute to the increased nTiO(2) transport at pH 7. Under all examined ionic strength conditions at both pH 5 and 7, the breakthrough curves of nC(60) were reduced in the copresence of nTiO(2), and the corresponding retained profiles were higher than those without nTiO(2), indicating that the presence of nTiO(2) decreased the transport of nC(60) in quartz sand. Co-deposition of nC(60) with nTiO(2) in the form of nTiO(2)-nC(60) clusters as well as the deposition of nC(60) onto previously deposited nTiO(2) were responsible for the increased nC(60) deposition in the presence of nTiO(2) at pH 5, whereas deposition of nC(60) onto surfaces of predeposited nTiO(2) was found to be responsible for the increased nC(60) deposition at pH 7.
Fano resonances are numerically predicted in an ultracompact plasmonic structure, comprising a metal-isolator-metal (MIM) waveguide side-coupled with two identical stub resonators. This phenomenon can be well explained by the analytic model and the relative phase analysis based on the scattering matrix theory. In sensing applications, the sensitivity of the proposed structure is about 1.1 x 10(3) nm/RIU and its figure of merit is as high as 2 x 10(5) at lambda=980 nm, which is due to the sharp asymmetric Fano line-shape with an ultra-low transmittance at this wavelength. This plasmonic structure with such high figure of merits and footprints of only about 0.2 mu m(2) may find important applications in the on-chip nano-sensors.
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.