• Brink Klemmensen posted an update 5 hours, 16 minutes ago

    This review summarizes the existing treatment processes and their possible up-gradation with the aim to accomplish the marked effluent standards for the nutrients. The concept of conventional systems and advanced systems for nutrients (nitrogen and phosphorous) removal which are already developed or under development are deeply discussed. Further, the challenges of each treatment systems are abridged. Finally, the possible suggestions for the modification/retrofitting of existing treatment systems for achieving stringent disposal standards are pointed out.To avoid recycling plastic waste containing polybrominated diphenyl ethers (PBDEs) or hexabromocyclododecane (HBCD), which are listed in the Stockholm Convention on Persistent Organic Pollutants (POPs), a simple method to determine their contents at the time of waste disposal is needed. Herein, we developed a rapid analytical method using a gas chromatograph coupled with quadrupole mass spectrometry or electron capture detection to simultaneously detect PBDEs and HBCD in plastic waste. PBDEs and HBCD were ultrasonically extracted from plastic samples using toluene. The dissolved polymer matrix was then removed using n-hexane and 44% H2SO4-impregnated silica gel before analysis of the extract. A run time of less than 10 min was achieved using a custom, short GC column (5 m). The detection limits of the method were below the upper threshold of the low POP content limits defined by the Basel Convention ( less then 1000 mg kg-1 for both PBDEs and HBCD). The accuracy of the method was confirmed by analyzing seven polymer reference materials. The determined PBDE and HBCD concentrations in most of these reference materials were within 30% of the certified values; the coefficients of variation in triplicate analysis were also within 30%. The concentrations of PBDEs and HBCD in actual plastic waste measured by this method were comparable with those obtained by more sophisticated and expensive methods, such as GC-high-resolution MS for PBDEs and liquid chromatography-tandem mass spectrometry for HBCD. Hence, the method developed herein is a less expensive alternative for identifying PBDE- and HBCD-containing wastes.The existing keyword spotting (KWS) techniques can recognize pre-defined keywords well but have a poor recognition accuracy for user-defined keywords. In real use cases, there is a high demand for users to define their keywords for various reasons. To address the problem, in this work, three techniques have been proposed, including incremental training with revised loss function, data augmentation, and fine-grained training, to improve the accuracy for the user-defined keywords while maintaining high accuracy for pre-defined keywords. The proposed techniques are applied to a classical KWS model (cnn-trad-fpool3) and a state-of-the-art KWS model (res15) respectively. The experimental results show that the proposed techniques have better recognition accuracy than several existing methods for the recognition of use-defined keywords. With the proposed techniques, the recognition accuracy of user-defined keywords on cnn-trad-fpool3 and res15 are significantly improved by 21.78% and 24.42%, respectively.This paper investigates the quasi-synchronization problem of the stochastic heterogeneous complex dynamical networks with impulsive couplings and multiple time-varying delays. It is shown that this kind of dynamical networks can achieve exponential quasi-synchronization by exerting impulsive control added on only one chosen pinning node. By employing the Lyapunov stability theory, some sufficient criteria on quasi-synchronization for this dynamical network are established, revealing the relationship between the quasi-synchronization performance and the stochastic perturbations as well as the frequency and strength of impulsive coupling. Finally, some numerical examples are used to illustrate the effectiveness of the main results.The radiative and non-radiative decay processes of five compounds are investigated through a comprehensive computational approach, for the aim of investigating the effect of different halogen substituents to the phosphorescent emission. Their optimal configurations at the ground (S0) and lowest triplet excited (T1) states are obtained and the calculated phosphorescent emission spectra are comparable with the experimental values. For 1,4-di(9H-carbazol-9-yl)benzene (PDCz), the electronic transition is between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), while for the four halides, the electronic transitions are attributed to several molecular orbitals. According to calculations, 9,9′-(2,5-diiodo-1,4-phenylene)bis(9H-carbazole) (PDICz) possesses the largest radiative decay rate constant (kr) and non-radiative decay rate constant (knr), which can be attributed to the strong spin-orbital coupling from the heavy iodine atom. However, the phosphorescent quantum efficiency (Φ) of PDICz is lower than that of 9,9′-(2,5-dibromo-1,4-phenylene)bis(9H-carbazole) (PDBCz), implying that a comprehensive consideration is necessary. Furthermore, by analyzing the vibrational mode, we have confirmed that the reorganization energies are also influenced by the different halogen atoms. While the dominated factor that determines the kr and knr comes from the spin-orbital coupling. selleck inhibitor We expect that our research findings will be beneficial to the newly designed organic phosphorescent materials in the future.The silver nanoparticles have been frequently used in SERS detection, for their unique optical properties and sensitive surface Raman enhancement properties. However, as the preparation of silver nanoparticles will use polyvinylpyrrolidone (PVP) to achieve the effect of reducing agent and surfactant, the surface of the prepared silver nanoparticles will be wrapped by PVP, forming an insulating layer and an ill-defined AgNPs interface, which limits the plasmonic coupling between the laminates of AgNPs. This paper reported a simple method to remove PVP for high performance and reusable SERS substrate, and the residue of PVP was studied after clean centrifugal by ethanol or water. When the number of cleaning times reached 10, there was basically no residual of PVP. The cleaned AgNPs interface effectively enhanced the plasma resonance of the local surface (LSPR) and greatly improved the SERS activity of the substrate. Moreover, probe molecules (R6G) are introduced to study the influence of single molecule PVP on subsequent detection.