The usual means of solar farm condition monitoring are limited by the typically poor quality and low-resolution data collected. A micro-synchrophasor measurement unit has been adapted and integrated ...with a power quality monitor to provide the high-resolution, high-precision, synchronised time-series data required by analysts to significantly improve solar farm performance and to better understand their impact on distribution grid behaviour. Improved renewable energy generation at large solar photovoltaic facilities can be realised by processing the enormous amounts of high-quality data using machine learning methods for automatic fault detection, situational awareness, event forecasting, operational tuning, and planning condition-based maintenance. The limited availability of existent data knowledge in this sector and legacy performance issues steered our exploration of machine learning based approaches to the unsupervised direction. A novel application of the Clustering Large Applications (CLARA) algorithm was employed to categorise events from the large datasets collected. CLARA has been adapted to recognise solar site specific behaviour patterns, abnormal voltage dip and spike events using the multiple data streams collected at two utility-scale solar power generation sites in England. Fourteen days of empirical field data (seven consecutive summer days plus seven consecutive winter days) enabled this analytical research and development approach. Altogether, ∼725 million voltage measurement data points were investigated, and automatic voltage anomaly detection demonstrated.
•Novel apparatus was designed and installed in the solar farm to gather the μPMU data.•Time-series feature vector approximation performed to find optimal feature vector length.•CLARA was employed on large-scale μPMU data to identify abnormal voltage events.•This framework tested on two UK based solar sites for both summer and winter seasons.
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•DIET stimulation by electrical voltage (EV), and/or magnetite-addition.•Enhancing LCFA β-oxidation and successful handling up to 2.0 g COD/L/d.•Better than any of them, combing EV ...and magnetite achieved 0.22 L CH4/g CODadded.•EV disconnection led to a sharp CH4 production drop, recovered by reconnection.•PilA, and CO2 reduction-related genes less expressed when EV cut, and vice versa.
Although electrical voltage (EV) application is widely used for direct interspecies electron transfer stimulation (DIET-S) in anaerobic digestion (AD), three relevant questions are yet to answer, i.e., i) can EV stimulate AD of recalcitrant/toxic wastes, e.g., long chain fatty acid (LCFA)?, ii) is it beneficial to combine EV with other DIET-S strategy?, and iii) after microbial community enrichment, if EV is disconnected, will the enhanced AD performance be affected?. For answering these questions, we operated four reactors: CR, EVR, MR, and (EV-M)R, referring to control, EV-applied, magnetite-supplemented, and “EV-applied with magnetite-supplemented” reactors, respectively, using oleate as substrate. Maximal treatable organic loading rate in CR and DIET-S reactors was 0.75, and 2.00 g COD/L/d. CH4 production yields from EVR, MR, and (EV-M)R were 0.19, 0.16, and 0.22 L CH4/g CODadded, respectively. DIET-S enriched DIET-implicated species, and thermodynamically enhanced LCFA β-oxidation. Genes involved in CH4 generation via CO2 reduction in EVR, MR, and (EV-M)R, were 2.4, 2.6, and 4.0 times higher than CR, respectively. Considering its CO2 reduction capability, Methanothrix sp. is claimed to establish DIET network with Syntrophomonas sp. in DIET-S reactors. For answering the third question, we further operated EVR and (EV-M)R. EV disconnection sharply lessened CH4 production, however, EV reconnection caused performance recovery, without significant change in microbial community structure. Relative abundances of pilA, ATPase, and hydrogenotrophic methanogenesis-related genes were increased by EV reconnection, and vice versa. This study provides engineering tool for enhancing LCFAs degradation, and scientific clues for the importance of continuous EV application, as DIET-S warranty.
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•Production and evaluation of self-sensing materials under various loads.•Friction Stir Processing’s influence on electrical response was analyzed.•Consistent electrical responses ...observed in pulse and cyclic load tests.•Polarization direction and thickness affect sensitivity, aiding SSM behaviour comprehension.•Electrical response occurs only with pulse loads, confirming the piezoelectric effect.
Recent advancements in materials engineering have addressed challenges in integrating sensory properties into metallic components, notably through Self-Sensing Materials (SSMs) embedding piezoelectric particles like Barium Titanate (BT) via Friction Stir Processing (FSP). This study explores self-monitoring metallic parts obtained by incorporating BT particles in AA5083-H111 plate via FSP, evaluating their behaviour under cyclic and pulse loads for real-time operational insights. The study explores how manufacturing processes affect SSMs’ electrical voltage response, focusing on FSP’s impact on different nugget regions, investigating polarization direction, electrode positioning, thickness effects, and performance under pulse loads. Findings indicated consistent electrical responses across specimens, with sensitivity affected by polarization direction and thickness. There was no evidence of electrical voltage response for constant loads. The pulse and cyclic loads triggered an electrical response, exhibiting a piezoelectric behaviour. The study highlights the intricate relationship between specimen features and piezoelectric properties, offering insights into optimizing SSM performance.
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•Electrical voltage (EV, 0.3 V) was applied for facilitating granulation in UASB.•EV could form big, settleable, and hydrophobic granules within 50 d.•EV also increased the specific ...methanogenic activity up to two times.•Pseudomonas and Methanosaeta relative abundances were 17 and 28% higher in EV.•Increased expression of quorum sensing genes by 27 times.
Despite having high-rate methanogenic performance, up-flow anaerobic sludge blanket reactor still has challenges regarding long-start up period (3–8 months) for granulation. In this study, “electrical voltage (EV, 0.3 V) application” was attempted for facilitating granulation in the continuous operation with increased organic loading rates (0.5–11.0 kg COD/m3/d). Up to 11.0 kg COD/m3/d, EV-reactor exhibited the stable performance, while the control failed. After 49 days of operation (at 7 kg COD/m3/d), the granules collected from EV-reactor had larger diameter (2.3 vs 1.6 mm), higher settling velocity (2.6 vs 1.9 cm/s), and higher hydrophobicity (52.1 % vs 34.5 %), compared to the control. EV application also increased the specific methanogenic activity for propionate and hydrogen almost by two times. The relative abundance of Pseudomonas sp. (quorum sensing (QS)-related microbe) in EV-reactor was 17 % higher than that in the control. In addition, EV application increased the expression of QS genes significantly by 27 times.
Plants play an extremely important role in environmental cleanliness by reducing harmful gases in the atmosphere. Spathiphyllum spp. and African violet (Saintpaulia ionantha) plants are widely found ...in many countries of the world, decorative inside. Since these two plants are commercially propagated throughout the world, they have economic importance at the same time. Spathiphyllum spp. also has a separate prescription due to its ability to clean some air toxins in the interior. Simultaneously monitoring, the frequencies and electrical voltage values per hour were measured by using oscilloscope for during one day on the leaves of these plants. African violet plant decrease and Spathiphyllum spp. increase are showed in frequency values especially at night and in the near morning. The change in voltage values in the Spathiphyllum spp. plant was particularly reduced in the morning and the changes were clearer until the evening, and the voltage change in the African violet plant was at very low levels.
We present a detailed study of the Li+ ion adsorption on two different hydrogenated carbon nanostructures, namely as pristine graphene (PG) and topologic Stone-Wales defective graphene (SWG) using ...the density functional theory (DFT). The studies are focused to analyze the structure-stability relationship with the estimated electronic and electrical properties for lithium-ion batteries (LIB) formed with an anode based on the Li/Li+#PG and Li/Li+#SWG systems. In addition, the electronic effects induced due to Li+ adsorption and the presence of SW defect on the graphene models were analyzed by the frontier molecular orbitals, ChelpG charges, Raman and UV–Vis spectra. It was verified that Li+ is more stably adsorbed on the edges on both graphene structures through an electrostatic interaction between cation and more negatively charged edges of nanostructures. TD-DFT calculations showed that the metallic nature of isolated graphene is disturbed after the adsorption of Li+, and this was demonstrated from the calculated HOMO-LUMO gap. The same Li+-Graphene geometries were optimized by introducing neutral charge in order to enable the calculation of ionization potentials. I was also found that such systems potentially contributed to the modeling of graphene-based anodes with reasonable electrical voltage responses estimated for a LIB. The simulation of Raman and UV–Vis spectra revealed significant variations in intensity and shifts the typical bands of graphene due to the presence of the Li+ ion that can contribute to point out new experiments to the spectroscopic characterization of these systems. Our results suggest that these carbon nanostructures are potential candidates for efficient applications in electrochemical systems, mainly dealing with LIB.
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•Li-Graphene interactions are evaluated as potential anodic systems in LIB.•Li + ion adsorption is thermodynamically more stable on the edges of graphene.•The SW defect in graphene can reduce the electrical voltage of the LIB.•There is an increase in the metallic character of Li/Li+-Graphene systems.
Based on the Hall effect, a magneto-acousto-electrical tomography (MAET) has been indicated to have a good ability for distinguishing the conductivity variations along the acoustic propagation ...direction, and B-scan imaging of the MAET is expected to obtain pathological information of the tissue. For achieving a clear B-scan image, in this paper, we designed and implemented a MAET system with a planar transducer and conducted a series of experiments to explore the characteristics of the magneto-acoustic-electrical (MAE) signal and electromagnetic interference (EMI) signal. The influence of the EMI signal on the MAE voltage signal was demonstrated experimentally, and the generation mechanism of the EMI signal was explained. Concurrently, several effective methods were proposed for reducing the EMI signal and improving the imaging resolution of the B-scan image. Additionally, for obtaining a B-scan image with high resolution, the detection front end was redesigned and algorithms applying the characteristics of the MAE signal were proposed. The accuracy, feasibility, and effectiveness of the improved methods were verified. Finally, a B-scan image was reconstructed with the relative amplitude of the conductivity. The results showed that: 1) the MAE signal obtained by the redesigned platform could be well separated from the EMI signal and had a higher SNR than that obtained by the previous detection system; 2) the proposed imaging algorithms had a high detection accuracy and achieved an axis resolution of 1 mm on the z-axis; and 3) the interfaces of the conductivity changes of homogeneous phantoms with 0.5% salinity were clearly presented by measuring the MAE wave packets, and the measured thicknesses of the phantoms were highly consistent with the actual thicknesses. This paper provides a theoretical and experimental basis for detecting the interface positions of conductivity variation, and the presented MAET technology is expected to become an alternative medical imaging modality for the early diagnosis and detection of biological cancerous tissues.
This study investigates the effect of input current direction on the electrical voltages of ultra-high-performance concrete containing fine steel slag aggregates (UA). For the application of ...electrical impedance tomography based on Laplace’s equation, electrical voltage should be identical under different input current directions. However, the electrical voltages of UA differ significantly corresponding to forward and backward current directions. The percentage differences of real voltages (VRE¯) corresponding to different input current directions are between 4.57% and 76.39% under different boundary conditions such as Wenner, same-boundary, and opposite-boundary conditions. VRE¯ originates from a different internal resistance of the internal path (Rip) corresponding to the input current direction. Among the investigated boundary conditions, the Wenner boundary condition provides the lowest VRE¯ because it leads to the generation of an almost uniform current density between the two inner probes used for measuring voltages than other conditions.
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