Disintegration of excess activated sludge--evaluation and experience of full-scale applications.

Anaerobic digestion of sewage sludge can be improved by introducing a disintegration of excess activated sludge as a pretreatment process. The disintegration brings a deeper degradation of organic matter and less amount of output sludge for disposal, a higher production of biogas and consequently energy yield, in some cases suppression of digesters foaming and better dewaterability. The full-scale application of disintegration by a lysate-thickening centrifuge was monitored long term in three different WWTPs. The evaluation of contribution of disintegration to biogas production and digested sludge quality was assessed and operational experience is discussed. Increment of specific biogas production was evaluated in the range of 15-26%, organic matter in digested sludge significantly decreased to 48-49%. Results proved that the installation of a disintegrating centrifuge in WWTPs of different sizes and conditions would be useful and beneficial.     

Magnetic field effect on mixed convection in a lid-driven square cavity filled with nanofluids

A numerical investigation of laminar mixed convection heat transfer in a lid-driven cavity filled with nanofluid under the influence of a magnetic field is executed. The left and right vertical walls of the cavity are insulated while the top and bottom horizontal walls are kept constant but different temperatures. The top wall is moving on its own plane at a constant speed while other walls are fixed. A uniform magnetic field is applied in the vertical direction normal to the moving wall. The governing differential equations are discretised by the control volume approach and the coupling between velocity and pressure is solved using the SIMPLE algorithm. The heat and mass transfer mechanisms and the flow characteristics inside the cavity depended strongly on the strength of the magnetic field. A comparison is also presented between the results obtained from the Maxwell and modified Maxwell models. The results show that the heat transfer is generally higher based on the modified Maxwell model.     

Simultaneous synthesis and consolidation of nanostructured TaSi2–Si3N4 composite by pulsed current activated combustion

Dense nanostructured 4TaSi₂–Si₃N₄ composite was synthesized by pulsed current activated combustion synthesis (PCACS) method within 3 min in one step from mechanically activated powders of TaN and Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of a pulsed current and mechanical pressure. Highly dense 4TaSi₂–Si₃N₄ composite with relative density of up to 98% was produced under simultaneous application of a 60 MPa pressure and the pulsed current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.     

Simultaneous high-frequency induction heated combustion synthesis and consolidation of nanostructured HfSi2–SiC composite

Dense nanostructured HfSi₂–SiC composite was synthesized by high-frequency induction heated combustion synthesis (HFIHCS) method in one step from powders of mechanically activated HfC and Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of an induced current and mechanical pressure. Highly dense HfSi₂–SiC was produced under simultaneous application of a 60 MPa pressure and the induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.     

Suppression of inherent ferromagnetism in Pr-doped CeO(2) nanocrystals

Ce(1-x)Pr(x)O(2-δ) (0 ≤x≤ 0.4) nanocrystals were synthesized by self-propagating method and thoroughly characterized using X-ray diffraction, Raman and X-ray photoelectron spectroscopy and magnetic measurements. Undoped CeO(2) nanocrystals exhibited intrinsic ferromagnetism at room temperature. Despite the increased concentration of oxygen vacancies in doped samples, our results showed that ferromagnetic ordering rapidly degrades with Pr doping. The suppression of ferromagnetism can be explained in terms of the different dopant valence state, the different nature of the vacancies formed in Pr-doped samples and their ability/disability to establish the ferromagnetic ordering.     

Rapid consolidation of nanocrystalline 3Ni–Al2O3 composite from mechanically synthesized powders by high frequency induction heated sintering

Nanopowders of Ni and Al₂O₃ were synthesized from 3NiO and 2Al powders by high energy ball milling. Nanocrystalline Al₂O₃ reinforced composite was consolidated by high frequency induction heated sintering method within 2 min from mechanically synthesized powders of Al₂O₃ and 3Ni. The relative density of the composite was 96%. The average hardness and fracture toughness values obtained were 645 kg/mm² and 6.3 MPa m^1/2, respectively.     

Properties and rapid consolidation of ultra-hard tungsten carbide

Extremely dense WC with a relative density of up to 99% was obtained within 3 min under a pressure of 80 MPa using the high frequency induction heating sintering method (HFIHS) method. The average grain size of the WC was about 87 nm. The advantage of this process is not only rapid densification to obtain a near theoretical density but also the prohibition of grain growth in nanostructured materials. The hardness and fracture toughness of the dense WC produced by the HFIHS were investigated.     

Pressure Effect on the Coexistence of Magnetism and Superconductivity in Ho1−x Dy x Ni2B2C

We have measured the transport properties of Ho_(1–x)Dy _x Ni₂B₂C (x=0.1, 0.4) single crystals to study the effects of high pressure conditions on the superconductivity and magnetism. The pressure affects the pair-breaking interaction by changing the magnetic exchange integral J _sf. In the case of x=0.1, the superconducting transition temperature T _c is higher than the Néel temperature T _N and decreases as the pressure increases. On the other hand, for x=0.4, when have lower T _N than T _c, T _c does not change with increasing pressure. These results are due to the effect of the pressure on J _sf.     

Anomaly detection of smart metering system for power management with battery storage system/electric vehicle

A novel smart metering technique capable of anomaly detection was proposed for real-time home power management system. Smart meter data generated in real-time were obtained from 900 households of single apartments. To detect outliers and missing values in smart meter data, a deep learning model, the autoencoder, consisting of a graph convolutional network and bidirectional long short-term memory network, was applied to the smart metering technique. Power management based on the smart metering technique was executed by multi-objective optimization in the presence of a battery storage system and an electric vehicle. The results of the power management employing the proposed smart metering technique indicate a reduction in electricity cost and amount of power supplied by the grid compared to the results of power management without anomaly detection.     

Harnessing the Formation of Natural Killer–Tumor Cell Immunological Synapses for Enhanced Therapeutic Effect in Solid Tumors

The formation of an immunological synapse (IS) on recognition of a cancer cell is the main mechanism underlying the natural killer (NK)-cell-mediated killing of tumor cells. Herein, an integrative strategy for cancer therapy against solid tumors is reported, in which alterations in the cleft of IS, following the secretion of acidic granular content, are utilized as a trigger for the delivery of chemotherapeutic drugs. NK cells are decorated with the IS-environment-responsive micellar system to ensure the release of the payload when they attack cancer cells. Using this strategy, the immunological cytotoxic killing effect of NK cells against solid tumors is reinforced with the site-specific diffusion of chemotherapeutic agents. Harnessing the intrinsic mechanism for the recognition of abnormal cells and the tumor-homing effect of NK cells limit the adverse systemic effects of chemotherapeutic drugs. This approach may provide a pragmatic platform for the universal and effective utilization of IS formation.