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Research was done on the reaction chemistry in the afterglow of oxygen in helium, which is studied, by ultraviolet absorption spectroscopy, optical emission spectroscopy and numerical modeling. In conclusion, the etching rate of polyimide correlated with the concentration of oxygen atoms in the afterglow, indicating that the O atoms were the active species involved in the process.

The transmittance of the p-doped hole transporting layer (p-HTL) and the charge generation layer (p-CGL) corresponding to the photoluminescence (PL) of blue dopants in an emitting layer decreases as the ratio of the p-dopant increases due to the absorption of the p-dopant. However, there was little difference in the luminous efficiency of blue top-emitting organic light-emitting diodes using p-HTL or p-CGL at a maximum doping ratio of 20%. p-HTL for a single structure required a 5% doping ratio to ensure sufficient electrical characteristics, but p-CGL for the two-stack tandem structure required more than a 10% doping ratio. The optical simulation showed that the device was affected by the specific absorbance of the p-dopant depending on the doping ratio and thickness. Although there was no significant difference in efficiency depending on the doping ratio at a thickness of 10 nm, the reduction rate of the external quantum efficiency increased from over 20 nm due to the doping ratio. [ABSTRACT FROM AUTHOR]

Reported herein are solution-processed polymer anode electrodes for blue phosphorescent organic light-emitting diodes (PhOLEDs). The highly conductive anodes were made from 10-wt%-methyl-red-(MR)-doped poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (PH1000) films. The red-colored and uniform polymer films demonstrated electrical conductivity values that significantly increased from 0.25 to 50 S·cm−1 after doping. The more than 200-fold enhancement in conductivity indicates that the doped films have a lower sheet resistance and better hole injection and transport properties than the pristine films. The resultant PhOLEDs based on the doped polymer anodes exhibited stable, broad, and intense blue emission at 468 nm with a 2616 cd·m−2 maximum luminance and a 4 V turn-on voltage. The obtained study results confirmed the effectiveness of the MR dye as a dopant for the significant enhancement of the conductivity and effective hole injection of PEDOT:PSS. Efficient future flexible optoelectronic applications can be built using this highly conductive polymer electrode obtained via a simple, solution-processed, and cost-effective doping approach. [ABSTRACT FROM AUTHOR]

In order to evaluate the efficacy of using reduced sulfur species in lieu of conventional substrates, a sequencing batch reactor (SBR) was used to develop an autotrophic denitrifying culture which in turn was used to seed a static granular bed reactor (SGBR) for continuous flow treatment. Both bioreactors were able to quickly acclimate to the anoxic environment and achieve stable autotrophic denitrification within several weeks of being placed in operation. The seed for the SBR was obtained from operating basins at the Cedar Rapids plant. MiSeq analysis showed the presence of the autotrophic denitrifier Thiobacillus in the seed from the sulfur oxidation basin; however, Shinella and Sulfurovum became the dominant autotrophic denitrifiers in the SBR. Both the SBR and SGBR achieved excellent nitrate removal (i.e., >95%) with stoichiometric amounts of thiosulfate added to the synthetic influent. The results of this feasibility study suggest that anaerobic granules from the UASB at the plant serve as good seed biomass for autotrophic denitrification when augmented by sulfur oxidation basin and sulfide scrubber biomass, and that reduced sulfur species at the plant (or augmented with an external sulfur source) can serve as electron donors for nearly complete denitrification. Practitioner points: Autotrophic denitrification of industrial wastewater was investigated to evaluate reduced sulfur species as electron donor for nitrogen removal.An autotrophic denitrifying culture was cultivated in an SBR, and continuous autotrophic denitrification was accomplished in an SGBR.No increase in head loss was observed in the SGBR, and it was able to operate without the need for backwashing in more than 200 days of operation.Reduced sulfur was demonstrated to be a sufficient electron donor for nearly complete denitrification.MiSeq analysis resolved primary species responsible for autotrophic denitrification in this study. [ABSTRACT FROM AUTHOR]