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Maintaining stability in modern power systems is challenging due to complex structures, rising power demand, and load disturbances. The integration of renewable energy sources further threatens stability by causing imbalances between generation and demand. Conventional load frequency stabilization methods fall short in such scenarios. This paper proposes an optimal fractional‐order proportional‐integral‐derivative‐acceleration (FOPIDA) controller, enhanced by a robust adaptive neuro‐fuzzy inference system (ANFIS), to improve load frequency control and reliability in power systems with wind and solar generators. First, the dynamical model of a multi‐area interconnected power system, including a thermal power plant, wind turbine, and solar photovoltaic generators, is developed. A decentralized ANFIS‐FOPIDA controller is then designed for load frequency control objectives. The gains of this controller are optimized using the whale optimization algorithm (WOA), focusing on frequency deviation and tie‐line power exchange. Simulations on a New England IEEE 10‐generator 39‐bus power system demonstrate the approach's effectiveness under various disturbances, including random load‐generation disturbances and nonlinear generation behaviors. Comparisons with other strategies, such as fractional order (FO) beetle swarm optimization algorithm (FOBSOA)‐FOPIDA, WOA‐PIDA, and WOA‐ANFIS‐PIDA, and recent control approaches highlight the superior performance of the WOA‐ANFIS‐FOPIDA method in enhancing power system stability. [ABSTRACT FROM AUTHOR]

Because of the large number of parameters that interact in amplifier functions, determining dynamic regime parameters as well as the mode of function of amplifier stages is an extremely complex problem. This paper describes a LabVIEW application for studying the functioning of an amplifier in various connections. The user selects the generator's parameters, the type of connection and its parameters, as well as the load circuit characteristics. The application can determine both the stage characteristics and the Bode characteristics. The amplifier's stability zone, as well as its gain and phase, are determined based on these characteristics. An important advantage of this application is that the design of the amplifier stage can be created starting from some parameters that the amplifier can establish, from which the values of components can be determined. In order to validate the simulation results from the LabVIEW application, the specialized program Multisim was used, as well as experimental measurements using the Electronics Explorer Board. Both Multisim and Electronics Explorer Board can determine Bode characteristics. In both simulations and experimental amplifiers, the same schemes with the same transistor were used. The application can be used for educational purposes as well as to design an amplifier's stage to achieve specific parameters. [ABSTRACT FROM AUTHOR]

At present, HTS magnets cannot operate in the real closed-loop persistent current mode due to the existence of joint resistance, flux creep, and AC loss of the HTS tape. Instead of using a current source, HTS flux pumps are capable of injecting flux into closed HTS magnets without electrical contact. This paper presents a practical superconducting DC dynamo for charging a conduction-cooled HTS magnet system based on a flux-pumping technique. To minimize heat losses, the rotor is driven by a servo motor mounted outside the vacuum dewar by utilizing magnetic fluid dynamic sealing. Different parameters, such as air gap and rotating speed, have been tested to investigate the best pumping effect, and finally, it successfully powers a 27.3 mH HTS non-insulated double-pancake coil to the current of 54.2 A within 76 min. As a low-cost and compact substitute for the traditional current source, the realization of a contactless DC power supply can significantly improve the flexibility and mobility of the HTS magnet system and could be of great significance for the technological innovation of future HTS magnets used in offshore wind turbines, biomedical, aerospace, etc. [ABSTRACT FROM AUTHOR]

The flywheel-type dual-stator permanent magnet starter generator combines engine flywheel and starter generator rotor into a single unit, which has the advantages of high efficiency, high power density, and compact structure. This paper proposes a new type of dual-stator permanent magnet starter generator topology in which the two stators are concentric and share the same permanent magnet rotor. Equivalent magnetic circuit modeling of the inner stator's magnetic field, outer stator's magnetic field, and synthetic magnetic field using the equivalent magnetic circuit method list the system of flux equations and solve the main magnetic flux, leakage flux, and leakage coefficient, and the results show that the equivalent magnetic circuit method has smaller error and higher accuracy than the finite element method. The harmonic electric potential of the starter generator is modeled and analyzed. The permanent magnet rotor and inner and outer stator structures are optimized to obtain the optimal parameters, and the prototype is manufactured and tested. The optimized starter generator no-load induced electromotive force fundamental amplitude is improved. The induced electromotive force harmonic distortion rate is reduced, and the output performance of the whole generator is significantly improved. [ABSTRACT FROM AUTHOR]

After long-term operation of a generator, the stator winding will gradually experience aging or electrical corrosion, and scientific experimental analysis methods are needed to diagnose the health status of equipment. By analyzing the leakage current data of stator winding DC withstand voltage tests of multiple large tubular generators, this paper proposed an insulation performance evaluation method and measures to prevent winding breakdown; according to the electrical corrosion and high operating temperature of stator winding of wall mounted structure, we studied a series of innovative designs and processes for stator renovation, and conducted finite element simulation calculation of stator temperature field. The temperature rise test data shows that the operating temperature of the generator after stator modification is effectively reduced, and there is significant reduction in temperature deviation at each measuring point. The research results are close to the simulation calculation values, proving that the new process adopted for stator transformation is effective and feasible. [ABSTRACT FROM AUTHOR]

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This paper provides a proof of concept for a linear electric generator that can be used to harvest energy from various sources of linear motion, such as vibrations, free-piston engines and wave energy. The generator can be used to power small electronic devices, such as sensors, or charge household batteries. The literature was reviewed to develop an understanding about the applications, control methods, excitation methods and mechanics of rotating and linear electric machines. A bidirectional, two-sided linear machine was designed with two stator cores and a single mover core. The stator windings and mover winding can be independently excited, allowing for three modes: no mover excitation, a DC excited mover, and an AC excited mover. Simulation results showed that the magnetic flux generated by DC excited stator cores were concentrated in the centre of the mover core. The use of two stator cores eliminates lateral flux in the mover core when it is not excited, minimising attraction and repulsion forces. Parametric analysis showed that flux cutting occurred in all operation modes, verifying that the generator will produce power when operating. Hardware tests produced an output current when the machine was electrically and mechanically excited, verifying the proposed design. [ABSTRACT FROM AUTHOR]

The rise of the renewable energy sources (RES) in microgrids has increased the impact of damping and low inertia on network stability. This gives rise to several issues in the power systems, including power fluctuations from variable RES, degradation of the frequency regulation, voltage surges, and oversupply from grid‐connected distributed generators. This paper presents a cascaded hybrid load‐frequency controller for an airport microgrid that addresses frequency fluctuations caused by load changes. It is combining a self‐adaptive fuzzy controller (SAF) and a classical two‐degree‐of‐freedom proportional integral derivative (PID) controller (2DOFPID) called CSAF‐2DOFPID. It is applied to the control section of a diesel generator, an electric aircraft energy storage system, and a demand response program. The controller parameters are optimized using a suggested hybrid differential artificial hummingbird algorithm (D‐AHA) to minimize frequency deviation. The proposed control framework is simulated on an airport microgrid comprising various components, and the impact of time delay on the controller's signals, system uncertainty is also examined. The simulation results demonstrate that the proposed self‐adaptive cascaded fuzzy controller outperforms other controllers such as PID, CF‐PID, and CF‐2DOFPID in reducing frequency fluctuations, and the D‐AHA algorithm achieves favourable results compared to other algorithms in the optimal tuning controller parameters. [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic has resulted in a permanent shift in individuals' daily routines and driving behaviours, leading to an increase in remote work. There has also been an independent and parallel rise in the adoption of solar photovoltaic (PV) panels, electrical storage systems, and electric vehicles (EVs). With remote work, EVs are spending longer periods at home. This offers a chance to reduce EV charging demands on the grid by directly charging EV batteries with solar energy during daylight. Additionally, if bidirectional charging is supported, EVs can serve as a backup energy source day and night. Such an approach fundamentally alters domestic load profiles and boosts the profitability of residential power systems. However, the lack of publicly available post-Covid EV usage datasets has made it difficult to study the impact of recent commuting patterns shifts on EV charging. This paper, therefore, presents SPAGHETTI (Synthetic Patterns & Activity Generator for Home-Energy & Tomorrow's Transportation Investigation), a tool that can be used for the synthetic generation of realistic EV drive cycles. It takes as input EV user commuting patterns, allowing for personalised modeling of EV usage. It is based on a thorough literature survey on post-Covid work-from-home (WFH) patterns. SPAGHETTI can be used by the scientific community to conduct further research on the large-scale adoption of EVs and their integration into domestic microgrids. As an example of its utility, we study the dependence of EV charge state and EV charging distributions on the degree of working from home and find that there is, indeed, a significant impact of WFH patterns on these critical parameters. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of the performance evaluation of looped tube thermoacoustic power generators using numerical and experimental analysis. The study focuses on small-scale generators operating at atmospheric pressure and utilizing low-cost linear alternators. The analysis considers factors such as temperature variation, pressure fluctuation, volume flow rate, and acoustic power distribution. The results show that the generators produce maximum acoustic power at a frequency of 78 Hz, with an overall thermal to electric efficiency of approximately 8.3%. The article also includes references to other research papers and articles that cover various aspects of thermoacoustic engines and generators, providing valuable insights into the field. [Extracted from the article]

This paper deals with the reactivation of three test benches of high, medium and low power electric generators for hydraulic energy conversion in the University of Carabobo Hydraulic Laboratory. The method involves three stages: i) Description of three high, medium and low power electric generators for hydraulic energy conversion, ii) Rehabilitation of three high, medium and low power electric generators for hydraulic energy conversion and iii) Evaluation of performance indexes of high, medium and low power electric generators for hydraulic conversion. The results indicate that for the low power electric generator, the position angle of the distributor blades is an experimental factor that has a significant effect on the response variables studied. With respect to the medium and high power electric generators, the most influential factor on operation and power generation is the flow supplied. [ABSTRACT FROM AUTHOR]

This paper focuses on modelling of Heat sink for thermoelectric Generator which requires a heat sink to achieve high electrical output efficiency. Thermoelectricity refers to a phenomenon in which a temperature gradient causes a flux of the electric charge. This work deals with models of different geometries, based on heatsinks designed to improve thermoelectric generator performance. The thermo-electric generator efficiency increased with the temperature gradient ΔT with the cooling junction. Here comparing of the conventional and analytical heat sinks, from analytical heat sinks, we can choose the beat efficient heat sink for thermoelectric generator high performance. The heat sink, whose device is to be improved by the geometry of the Heat sink models designed with different shapes of Fins, provides this cooling junction. After analyzing the various heat sink models, with different geometrical Heat sink fins, cylindrical-shaped fins's-height at 10 mm temperature cooled to 6.7℃ and pressure loss to 1.8Pa from high temperature were found to be most effective for thermoelectric generator efficiency. The improvement in temperature and pressure loss was achieved using the optimized cylindrical heat sink with 10mm fins height design. [ABSTRACT FROM AUTHOR]

This document is a correction to a previously published paper titled "Why the observed spin evolution of older-than-solar-like stars might not require a dynamo mode change." The correction addresses minor typographical errors that do not impact the results of the paper but could cause confusion in reproducing the calculations. Specifically, the correction involves changing the notation for stellar mass and radius in subsection 2.3. The corrected notation uses m⊙* and r⊙* to represent normalized values to solar mass and solar radius. The authors of the paper are Ketevan Kotorashvili, Eric G Blackman, and James E Owen. [Extracted from the article]

This document is a correction to a paper titled "Fundamental scales in the kinematic phase of the turbulent dynamo" published in the Monthly Notices of the Royal Astronomical Society. The correction addresses a typo in section 2.1 of the paper, specifically in the description of the traceless rate of strain tensor. The correct tensor is provided, and it is stated that the error only affected the reporting in the paper, not the results or conclusions of the study. [Extracted from the article]

A high-performance low-humidity sensor and moisture-enabled electric generator are prepared through a mesoporous silica-mediated polymerizable deep eutectic solvent platform. The strong hydrophilicity and high ionic conductivity of ionogels are the main reasons for realizing dual-function devices. This work provides a novel approach for the combination of humidity detection and utilization. [Display omitted] • Mesoporous silica/polymerizable deep eutectic solvent functionalized ionogels were prepared by UV light stimulation. • Mesoporous silica containing abundant hydroxyl groups can regulate the intermolecular forces in polymer networks. • Low-humidity sensing and moisture-enabled electric generation can be realized simultaneously through functionalized ionogels. Although technologies related to humidity detection and utilization, such as humidity sensors, atmospheric water harvesting, energy collection, and moisture-enabled electrical generation technologies, have been widely reported, there is still an urgent need for effective monitoring and utilization of humidity in low-humidity places. An ideal low-humidity sensor requires a high response, fast response time and low humidity hysteresis. Soft ion power supplies inspired by electric eels convert the chemical potential energy of ion gradients into electrical energy by utilizing humidity, but their production is challenging. This paper reports a new strategy for developing functionalized ionogels based on mesoporous silica and a polymerizable deep eutectic solvent (SiO 2 @PDES). Due to their strong hydrophilicity, high ionic conductivity, excellent adhesion, flexibility and mechanical strength, SiO 2 @PDES ionogels can not only detect low humidity but also generate electric power through a reasonably designed device structure. In the 5–30% RH range, the response of the SiO 2 @PDES humidity sensor reaches 1600%, with negligible humidity hysteresis (0.8% RH). As a biomimetic soft ion power supply, SiO 2 @PDES ionogels generate a high open-circuit voltage of ∼600 mV at 33% RH, which expands the environmental adaptability of moisture-enabled electrical generation equipment. In addition, the excellent moisture-enabled electrical generation performance endows portable wearable power supplies with high potential for applications such as charging capacitors and lighting LEDs. [ABSTRACT FROM AUTHOR]

Microgrids are extensively integrated into electrical systems due to their many technical, economic, and environmental advantages. However, they encounter a challenge as they experience high-frequency fluctuations caused by the stochastic nature of renewable energy generation, electric loads, and the presence of Electric Vehicles (EVs). Therefore, various techniques, algorithms, and controllers have been introduced to ensure effective Load Frequency Control (LFC) and maintain a stable power system in microgrids. These methods aim to ensure that the system's frequency remains stable and within an acceptable range, especially when faced with changing load demands and other factors. This paper presents a novel enhanced control approach, Particle Swarm Optimization-Trained Artificial Neural Network (PSO-TANN), to optimize the load frequency model of a microgrid with vehicle-to-grid integration. The results are then compared under various scenarios, including renewable energy integration, EV charging and discharging dynamics, and varying load demands. The comparative analysis involves assessing the performance of the conventional Proportional–Integral–Derivative (PID) controller, the PSO-PID controller, and the newly proposed controlling technique. The suggested controller attains 99.904% efficiency with a negligible mean squared error of 1.1112 × 10−7, decreasing the integrated time absolute error to 1.0 × 10−4. It shows rapid response, precise targeting, and quick peak output ability, with marginal overshoot and undershoot, and a transient time of 28.5626 s, efficiently controlling microgrid frequency. Stability analysis validates the effectiveness of the proposed PSO-TANN controller in ensuring stability within the microgrid's LFC system during uncertainties and disturbances. This establishes resilience, diminishes settling time, and maintains reliable performance while controlling frequency. • An investigation into an islanded microgrid's Load Frequency Control (LFC) model framework has been conducted, comprising diesel generator, solar PV system, wind turbine, and EVs operating in vehicle-to-grid mode to supply power to electric loads, consequently impacting the frequency dynamics of the microgrid system. • A novel enhanced control approach, Particle Swarm Optimization-Trained Artificial Neural Network (PSO-TANN) has been implemented to optimize the load frequency model of a microgrid. • An extensive comparative analysis with other controllers, including PID and PSO-PID, is conducted across diverse scenarios involving renewable energy integration and EV charging and discharging dynamics under various load disturbances to reduce settling time, control system frequency, and ensure reliable performance. • The stability analysis validates the efficiency of the proposed PSO-TANN controller in ensuring reliability during uncertainties and disturbances, maintaining overall robustness and stability of the LFC system within the microgrid. [ABSTRACT FROM AUTHOR]

Understanding the longevity of Mars's dynamo is key to interpreting the planet's atmospheric loss history and the properties of its deep interior. Satellite data showing magnetic lows above many large impact basins formed 4.1-3.7 billion years ago (Ga) have been interpreted as evidence that Mars's dynamo terminated before 4.1 Ga—at least 0.4 Gy before intense late Noachian/early Hesperian hydrological activity. However, evidence for a longer-lived, reversing dynamo from young volcanics and the Martian meteorite ALH 84001 supports an alternative interpretation of Mars's apparently demagnetized basins. To understand how a reversing dynamo would affect basin fields, here we model the cooling and magnetization of 200-2200 km diameter impact basins under a range of Earth-like reversal frequencies. We find that magnetic reversals efficiently reduce field strengths above large basins. In particular, if the magnetic properties of the Martian mantle are similar to most Martian meteorites and late remagnetization of the near surface is widespread, >90% of large (> 800 km diameter) basins would appear demagnetized at spacecraft altitudes. This ultimately implies that Mars's apparently demagnetized basins do not require an early dynamo cessation. A long-lived and reversing dynamo, unlike alternative scenarios, satisfies all available constraints on Mars's magnetic history. Weak magnetic fields above Mars's large impact basins are often interpreted as a signature of the dynamo's early cessation. Here, the authors demonstrate that these weakly magnetic basins may instead have formed in a long-lived but reversing dynamo. [ABSTRACT FROM AUTHOR]

Paleomagnetic analyses have suggested that the lunar magnetic field underwent a significant change from 4.25 to 3.19 Ga, indicating the rapid transition of the lunar dynamo mechanism. We used the van der Pauw (vdP) method to measure the electrical resistivity of Fe‐S‐P alloys under conditions relevant to the lunar core and estimated the thermal conductivity of the Fe‐S‐P lunar core. These values were incorporated into thermal and dynamo models to investigate the evolution of the lunar core. Our model indicates that the inner core began to grow as early as 4.35 Ga, the solidification regime switched at 3.50 Ga, and the thermal dynamo ceased between 3.78 and 3.51 Ga. The cessation of the dynamo could be due to a low buoyancy flux and insufficient entropy dissipation. Thermal and compositional dynamos cannot sustain the ancient strength of the Moon's magnetic field, and require other energy sources. Plain Language Summary: The transport properties of planetary core materials dominate heat transfer through thermal convection, which is closely linked to the geodynamo of the planetary core. The van der Pauw (vdP) method was used to measure the electrical resistivity of Fe‐S‐P alloy, and we assessed the effects of pressure, temperature, and light elements (sulfur and phosphorus) on the electrical resistivity of these alloys. We estimated the thermal conductivity of the Fe‐S‐P lunar core and modeled the growth of the lunar core. We found that the inner core nucleated at 4.35 Ga in the center and then solidified at the core‐mantle boundary (CMB) at 3.50 Ga. The adiabatic heat conduction at the lunar CMB indicated that a thermally driven dynamo persisted until 3.78–3.51 Ga in the Moon's history. We discuss the cessation of the lunar core dynamo in relation to the buoyancy flux, entropy, Reynolds number and Elsasser number and explain the variation in the magnetic field in conjunction with the previous dynamo mechanism. Key Points: The electrical resistivity and thermal conductivity of Fe‐S‐P alloys were determined at 3 and 5 GPaA low thermal conductivity Fe‐S‐P core nucleated earlier and the bottom‐up growth regime switched to a top‐down regime at 3.50 GaMultiple dynamo mechanisms worked together to generate a high magnetic field, low buoyancy flux and entropy dissipation causing the dynamo to cease [ABSTRACT FROM AUTHOR]

The absence or presence of a lunar paleomagnetosphere is important because it bears directly on the volatile content of the regolith and exploration targets for Artemis and other missions to the Moon. Recent paleointensity study of samples from the Apollo missions has readdressed this question. Multiple specimens from a young 2-million-year-old glass shows a strong magnetization compatible with that induced by charge-separation in an impact plasma, whereas paleointensities of single crystals yield evidence for null magnetizations spanning 3.9 to 3.2 Ga. Together, these data are consistent with an impact mechanism for the magnetization of some lunar samples, and absence of a long-lived lunar core dynamo and paleomagnetosphere recorded in other samples. Here, we present a dataset that allows researchers to examine replicates of these measurements. For the glass, we present data from specimens that fail standard paleointensity selection criteria but nevertheless imply a complex, changing magnetic field environment. For the single crystals, the replicate measurements further illustrate the initial zero magnetization state of these materials. [ABSTRACT FROM AUTHOR]

The details of the dynamo process in the Sun are an important aspect of research in solar-terrestrial physics and astrophysics. The surface part of the dynamo can be constrained by direct observations, but the subsurface part lacks direct observational constraints. The torsional oscillations, a small periodic variation of the Sun's rotation with the solar cycle, are thought to result from the Lorentz force of the cyclic magnetic field generated by the dynamo. In this study, we aim to discriminate between three Babcock–Leighton dynamo models by comparing the zonal acceleration of the three models with the observed one. The property that the poleward and equatorward branches of the torsional oscillations originate from about ±55° latitudes with their own migration time periods serves as an effective discriminator that could constrain the configuration of the magnetic field in the convection zone. The toroidal field, comprising poleward and equatorward branches separated at about ±55° latitudes, can generate the two branches of the torsional oscillations. The alternating acceleration and deceleration bands in time are the other property of the torsional oscillations that discriminates between the dynamo models. To reproduce this property, the phase difference between the radial (B r ) and toroidal (B ϕ ) components of the magnetic field near the surface should be about π /2. [ABSTRACT FROM AUTHOR]

This study presents a thermoset moulding compound designed for electrical machines with high power densities. The compound reduces residual stresses induced by the difference in thermal expansion during use and by shrinkage in the compound during the manufacturing process. To reduce the internal stresses in the compound, in the electrical sheet lamination and at their interface, first the moulding's coefficient of thermal expansion (CTE) must match that of the lamination because the CTE of the electrical sheets cannot be altered. Second, the shrinkage of the compound needs to be minimized because the moulding compound is injected around a prefabricated electrical sheet lamination. This provides greater freedom in the design of an electric motor or generator, especially if the thermoset needs to be directly bonded to the electrical sheet. The basic suitability of the material for the injection moulding process was iteratively optimised and confirmed by spiral flow tests. Due to the reduction of the residual stresses, the compound enables efficient cooling solutions for electrical machines with high power densities. This innovative compound can have a significant impact on electric propulsion systems across industries that use laminated electrical sheets. [ABSTRACT FROM AUTHOR]

Water droplets help life in nature survive, thrive, and evolve. With water droplet serving as one of the indispensable elements in the Internet of Things (IoT), many droplet‐oriented technologies, such as microfluidics, droplet manipulation, electrowetting, and energy harvesting, make rapid progress driven by material science, computer science, and medicine. Droplet‐based wearable devices are endowed with advantages such as flexibility, sensing ability, and automation for various parameter detection. Besides, the continuous exploration of droplet manipulation has led to the emergence of a wide variety of manipulation methods. Meanwhile, electrowetting that utilizes external fields modifying liquid–solid surfaces has found its applications in various areas, including droplet transportation, microfabrication, and healthcare. The energy generation from water droplets also presents exciting opportunities for the development of novel electricity generators. These approaches for droplet utilization underscore the immense potentials and versatilities of droplet‐based technologies in the IoT landscape. Hence, this mini review presents the fundamental droplet‐based technologies by summarizing their working mechanisms and methods, device structures, and applications. Given the challenges in materials, fabrication, and system integration, this review shows the overall development roadmap in terms of improved functionality and performance and highlights the opportunities toward multifunctional, self‐sustainable, and intelligent systems, which is called for IoT construction. [ABSTRACT FROM AUTHOR]

A critical component of predicting thermal convection and dynamo action in the cores of terrestrial planetary bodies is the adiabatic heat flux at the top of the core. Powders of Fe, FeS, and Fe-9wt%Si were mixed to imitate the core of Asteroid 4 Vesta, which studies of HED meteorites indicate is comprised of 13–16wt%S and 1–2wt%Si. In a 1000-ton cubic anvil press, the voltage drop across an Fe-16wt%S-2wt%Si sample of 8–10 mm3 was measured at 2, 3, 4, and 5 GPa and ~300–2000 K. The resistivity of Fe-16wt%S-2wt%Si is 400 ± 50 μΩ·cm for 2–5 GPa for the complete liquid state. Using the Wiedemann–Franz Law, this gives an electronic thermal conductivity of 11 ± 1.5 W/m/K for 2–4 GPa at complete melting and an adiabatic heat flow of 55 ± 15 MW at the top of an early Fe-16wt%S-2wt%Si Vestan core. The 2 GPa boundary of the miscibility of Fe-16wt%S-2wt%Si is observed. The adiabatic heat flow through an Fe-16wt%S-2wt%Si core of variable size is discussed, as well as the resistivity of liquid Fe alloy at small planetary core conditions as a function of S and Si alloying composition. On the basis of previous studies on binary and ternary alloys of Fe with S and/or Si, we interpolate the separate effects of S and Si on the resistivity (and inversely on thermal conductivity and core adiabatic heat flow). [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is highly corrosive to electric generators, which is the main problem of biogas utilization. The industrial scale of the biofilter system relies on the performance of sulfide-oxidizing bacteria (SOB) via the activity of sulfur oxidation (soxABXYZ) and flavocytochrome sulfide dehydrogenase (fccAB) enzymes to reduce to a concentration below 100 ppm before using in industrial machinery. The main purpose of this research is to investigate the SOB community in full-scale H2S removal and their gene expression (fccAB and soxABXYZ) associated with H2S elimination efficiency. In this study, SOB communities were obtained from 2 sampling sites of the full-scale biofilter of palm oil factory (PPG), comprising starting sludge (PPG1) and recirculating sludge (PPG2). The abundance of SOB strains was examined by next-generation sequencing analysis (NGS) based on the 16S rRNA gene. The changes in the expression of genes involved in sulfur oxidation, namely soxABXYZ, and fccAB, between the 2 sampling sites were evaluated by using a comparative genomic hybridization (CGH) microarray. The results indicate that the high abundance of SOB genera that could play a vital role in biofilters belonged mainly to Sulfurovum, Paracoccus, Acidihalobacter, Acidithiobacillus, Thioalkalispira, Thiofaba, Caldisericum, Bacillus, were rapidly increased in the biofilter tank. Interestingly, expressions of soxAXYZ gene cluster at PPG2 were increased in Paracoccus pantotrophus J40 and Paracoccus alkenifer DSM 11593 for 1.1188 and 1.0518-fold, respectively, while in Acidihalobacter prosperus F5, the expression of fccAB genes was up to 1.3704 fold in comparison with PPG1. Increasing both relative abundance and gene expressions at PPG2 were correlated with 95% H2S removal efficiency. Hence, stabilization of the SOB microbiome is vital to H2S removal in industrialscale biogas applications. [ABSTRACT FROM AUTHOR]

Abstract Maintaining stability in modern power systems is challenging due to complex structures, rising power demand, and load disturbances. The integration of renewable energy sources further threatens stability by causing imbalances between generation and demand. Conventional load frequency stabilization methods fall short in such scenarios. This paper proposes an optimal fractional‐order proportional‐integral‐derivative‐acceleration (FOPIDA) controller, enhanced by a robust adaptive neuro‐fuzzy inference system (ANFIS), to improve load frequency control and reliability in power systems with wind and solar generators. First, the dynamical model of a multi‐area interconnected power system, including a thermal power plant, wind turbine, and solar photovoltaic generators, is developed. A decentralized ANFIS‐FOPIDA controller is then designed for load frequency control objectives. The gains of this controller are optimized using the whale optimization algorithm (WOA), focusing on frequency deviation and tie‐line power exchange. Simulations on a New England IEEE 10‐generator 39‐bus power system demonstrate the approach's effectiveness under various disturbances, including random load‐generation disturbances and nonlinear generation behaviors. Comparisons with other strategies, such as fractional order (FO) beetle swarm optimization algorithm (FOBSOA)‐FOPIDA, WOA‐PIDA, and WOA‐ANFIS‐PIDA, and recent control approaches highlight the superior performance of the WOA‐ANFIS‐FOPIDA method in enhancing power system stability.

Traditional approaches to managing maintenance histories for repairing spalling involved time-consuming and non-intuitive information representation and manual practices. Therefore, this study introduces an innovative approach to improve the efficiency of roadway maintenance history management. To enable intuitive understanding of the spalling maintenance history through visualization, this study utilizes Autodesk Revit and developed Dynamo scripts to automatically input the spalling maintenance history stored in Excel into a 3D model, thereby creating a Building Information Modeling (BIM). The BIM, generated through the automatic input of maintenance history using Dynamo, is expected to enhance the efficiency of maintenance history management. Additionally, it will assist stakeholders in their decision-making process through the intuitive information provision. Furthermore, there is potential for this approach to be applied beyond roadways and the management of other infrastructures. • Spalling 3D models were created using Revit based on collected real-world data. • Dynamo enabled automatic information input between 3D models and Excel data. • BIM makes intuitive checking of spalls and integrated repair histories possible. • BIM and Dynamo replaced paper and Excel for integrated spall repair data management. [ABSTRACT FROM AUTHOR]

The integration of 3D laser scanning and digital photogrammetry in the architecture, engineering, and construction (AEC) industry has facilitated high-quality architectural surveys. However, the processes remains constrained by significant costs, extensive manual labor, and accuracy issues associated with manual data processing. This article addresses these operational challenges by introducing automated Building Information Modeling (BIM) techniques that minimize manual input through the use of Dynamo for Autodesk Revit. We developed algorithms that efficiently convert point cloud data into accurate BIM models, enhancing productivity and reducing the potential for errors. The application of these algorithms is analyzed in a case study of the Old Lifeguard Station of Fuseta, showcasing notable reductions in modeling time and improvements in accuracy. The findings suggest that automated scan-to-BIM methods could provide a viable solution for enhancing BIM workflows across the industry, with the potential for wider adoption given their impact on efficiency and model quality. [ABSTRACT FROM AUTHOR]

Considerable efforts have recently been made to augment the power density of moisture‐enabled electric generators. However, due to the unsustainable ion/water molecule concentration gradients, the ion‐directed transport gradually diminishes, which largely affects the operating lifetime and energy efficiency of generators. This work introduces an electrode chemistry regulation strategy into the ionic diode‐type energy conversion structure, which demonstrates 1240 h power generation in ambient humidity. The electrode chemical regulation can be achieved by adding Cl−. The purpose is to destroy the passivation film on the electrode interface and provide a continuous path for ion‐electron coupling conduction. Moreover, this device simultaneously satisfies the requirements of fast trapping of moisture molecules, high rectification ratio transport of ions, and sustained ion‐to‐electron current conversion. A single device can deliver an open‐circuit voltage of about 1 V and a peak short‐circuit current density of 350 µA cm−2. Finally, the first‐principle calculations are carried out to reveal the mechanism by which the electrode surface chemistry affects the power generation performance. [ABSTRACT FROM AUTHOR]

In drilling operations, measuring vibration parameters is crucial for enhancing drilling efficiency and ensuring safety. Nevertheless, the conventional vibration measurement sensor significantly extends the drilling cycle due to its dependence on an external power source. Therefore, we propose a vibration-accumulation-type self-powered sensor in this research, aiming to address these needs. By leveraging vibration accumulation and electromagnetic power generation to accelerate charging, the sensor's output performance is enhanced through a complementary charging mode. The experimental results regarding sensing performance demonstrate that the sensor possesses a measurement range spanning from 0 to 11 Hz, with a linearity of 3.2% and a sensitivity of 1.032. Additionally, it exhibits a maximum average measurement error of less than 4%. The experimental results of output performance measurement indicate that the sensor unit and generator set exhibit a maximum output power of 0.258 μW and 25.5 mW, respectively, and eight LED lights can be lit at the same time. When the sensor unit and power generation unit output together, the maximum output power of the sensor is also 25.5 mW. Furthermore, we conducted tests on the sensor's output signal in conditions of high temperature and humidity, confirming its continued functionality in such environments. This sensor not only achieves self-powered sensing capabilities, addressing the power supply challenges faced by traditional downhole sensors, but also integrates energy accumulation with electromagnetic power generation to enhance its output performance. This innovation enables the sensor to harness downhole vibration energy for powering other micro-power devices, showcasing promising application prospects. [ABSTRACT FROM AUTHOR]

The modelling and analysis of high‐frequency bearing voltage are of great significance to the assessment and mitigation of the electrical erosion risk in wind power systems. However, the dual‐winding permanent magnet synchronous generator (DW‐PMSG), as one of the mainstream models in wind power industry, has not been specifically analysed for its bearing voltage modelling method in the existing research. The high frequency common mode equivalent circuit model of DW‐PMSG is established, and the effect of parasitic parameters between two sets of winding on bearing voltage is analysed. A model parameters extraction method based on differential evolution algorithm is proposed, and the range of parameters is estimated by finite element simulation and test results, which improves the search efficiency and solution accuracy. The accuracy of the proposed model is verified by the comparison of simulation and experimental results. On this basis, it is possible to conduct more in‐depth research on the bearing voltage and bearing currents of DW‐PMSG, and provide theoretical basis and simulation means for the design of suppression schemes. [ABSTRACT FROM AUTHOR]

The starter generator, characterized by controllable starting torque and disturbance in generator load torque, poses challenges for the multi-electric aero engine control. The key to addressing this issue lies in multi-electric aero engine control with the collaboration of a starter generator. Firstly, a multi-electric aero engine model is established, comprising a full-state turbofan engine model to enhance low-speed simulation capability and an external characteristic model of a starter generator to improve real-time simulation capability. Subsequently, the control methods for a multi-electric aero engine with starter generator coordination are proposed in three processes, including the starting process, acceleration/deceleration process, and steady-state process. During the starting process, the acceleration is controlled by coordinating the torque of the starter generator and the fuel of the aero engine. During the acceleration/deceleration process, the fuel limit value is adjusted based on the electrical load of the starter generator. During the steady-state process, the fuel is compensated based on the q-axis current of the starting generator in response to load torque disturbance. Finally, hardware-in-the-loop simulation experiments are conducted for the control of a multi-electric aero engine. The results show that the coordination reduces the oscillation of the acceleration during the startup of a multi-electric aero engine, enhancing its ability to resist disturbances from electrical load fluctuations during power generation. [ABSTRACT FROM AUTHOR]

This study proposes an optimal approach for enhancing the quality of a weak electrical power distribution system by utilizing thyristor‐controlled series capacitors (TCSC). The proposed approach considers various system components, including shunt capacitors and distributed generators that rely on renewable energy sources, which are characterized by uncertainty due to changing weather conditions. The proposed system maximizes the benefits of these components by updating its parameters to improve the distribution power system's quality under all operating conditions, which change due to the varying energy generated by the distributed generators and load changes. The optimal TCSC values are calculated for all operating conditions using the Hyper‐Spherical Search with graded objective functions management strategy (HSSA‐GOFMS) algorithm. The GOFMS converts all restrictions into objective functions with limits and prioritizes the search for objectives according to a sequential system of priorities. This strategy prevents the possibility of non‐convergence. The results demonstrate the effectiveness of the proposed approach in improving the performance quality of a weak electrical distribution system. The proposed strategy achieves the target voltage level limits within nominal values, even with the interference of the system with generators distributed at variable power levels. Furthermore, the proposed approach enhances the performance quality of the system under a wide range of load changes. [ABSTRACT FROM AUTHOR]

First results are presented from the conjugate maneuvers performed by NASA's Ionospheric Connection Explorer (ICON) spacecraft. During each several‐minute maneuver, ICON crosses the magnetic equator, measuring the plasma drift at the ∼600‐km apex of a magnetic field line and the neutral wind profiles (∼90–300 km altitude) along both ends of that field line. The analysis utilizes 149 pairs of maneuvers separated by ∼24 hr but at nearly the same location and local time. Principal component regression reveals that 39 ± 7% and 24 ± 9% of the day‐to‐day variance in the daytime vertical and zonal drift, respectively, is attributable to conjugate neutral winds. The remaining variance is likely driven by external potentials from non‐conjugate winds and geomagnetic activity (median Kp 2−). Zonal winds at 100–113 km and >120 km altitude are the primary drivers of conjugate vertical and zonal drift variance, respectively. These observations can test vertical‐coupling mechanisms in whole‐atmosphere models. Plain Language Summary: The plasma that composes the ionosphere can change dramatically from one day to the next, exhibiting significant changes in its height and density which are not well predicted by models. This variability can have adverse impacts on satellite‐based navigation and communication systems, limiting their performance and availability. One of the key parameters that controls daytime ionospheric conditions is the upward and downward motion of plasma above 200 km, which affects the lifetime of newly created plasma. The force that puts the plasma in motion is electromotive, generated by the motion of the atmosphere (i.e., the wind) around 100–150 km that pushes charged particles across magnetic field lines. NASA's Ionospheric Connection Explorer is the first mission to directly observe these electrical generators, one at each "footpoint" of the arched magnetic field lines that thread the ionosphere and generator region. The results show that just under half of the day‐to‐day changes in ionospheric motion can be explained by this local generator mechanism. The major controller is the east‐west winds, with north‐south winds having only a minor influence on this mechanism. Key Points: The first data set of simultaneous plasma drift and magnetically conjugate neutral winds in both hemispheres is presentedThe day‐to‐day changes in winds account for 39 ± 7% and 24 ± 9% of the conjugate vertical and zonal daytime drift variance, respectivelyVertical drift variance is mainly driven by zonal winds at 100–113 km, and zonal drift variance is mainly driven by zonal winds above 120 km [ABSTRACT FROM AUTHOR]

A foil that is free to pitch and heave in an upstream flow can oscillate very regularly and with large amplitudes given that its inertial properties and support stiffness in pitch and heave are well adapted to the flow velocity. Useful energy can be extracted from these oscillations via an appropriate damping in heave that models the presence of an electric generator. In recent years, the structural parameters of such a fully passive oscillating-foil turbine (OFT) have been optimized, yielding a maximum energy extraction efficiency of 51.0% under the assumptions of 2D and unconfined flow. However, the turbine is normally deployed in channels with finite cross-sectional area, thus impacting the flow rate passing through the turbine via the blockage effect. In this work, we extend the applicability of the 2D optimized structural parameters to 2D confined scenarios with a simple tuning of the viscous heave damping coefficient. Performance is determined via a fluid-structure interaction solver based on an unsteady Reynolds-averaged Navier–Stokes approach. As expected, confining the turbine increases the heave amplitude and the power, up to a point where the motions become chaotic, and thus require an increase in the heave damping coefficient. This study shows that in all confined 2D scenarios, reasonably good performances of the fully passive OFT can be maintained when using its optimal structural parameters obtained in 2D unconfined conditions, given that the generator is adjusted accordingly. [ABSTRACT FROM AUTHOR]

In this study, real voyage data and ship specifications of a general cargo ship are employed, and it is assumed that diesel generators are replaced with hydrogen proton exchange membrane fuel cells. The effect of the replacement on CO2, NOX, SOX, and PM emissions and the CII value is calculated. Emission calculations show that there is a significant reduction in emissions when hydrogen fuel cells are used instead of diesel generators on the case ship. By using hydrogen fuel cells, there is a 37.4% reduction in CO2 emissions, 32.5% in NOX emissions, 37.3% in SOX emissions, and 37.4% in PM emissions. If hydrogen fuel cells are not used instead of diesel generators, the ship will receive an A rating between 2023 and 2026, a B rating in 2027, a C rating in 2028–2029, and an E rating in 2030. On the other hand, if hydrogen fuel cells are used, the ship will always remain at an A rating between 2023 and 2030. The capital expenditure (CAPEX) and operational expenditure (OPEX) of the fuel cell system are USD 1,305,720 and USD 2,470,320, respectively, for a 15-year lifetime, and the hydrogen fuel expenses are competitive at USD 260,981, while marine diesel oil (MDO) fuel expenses are USD 206,435. [ABSTRACT FROM AUTHOR]

We devise a general method for obtaining 0-form noninvertible discrete chiral symmetries in 4-dimensional SU(N)/ℤp and SU(N) × U(1)/ℤp gauge theories with matter in arbitrary representations, where ℤp is a subgroup of the electric 1-form center symmetry. Our approach involves placing the theory on a three-torus and utilizing the Hamiltonian formalism to construct noninvertible operators by introducing twists compatible with the gauging of ℤp. These theories exhibit electric 1-form and magnetic 1-form global symmetries, and their generators play a crucial role in constructing the corresponding Hilbert space. The noninvertible operators are demonstrated to project onto specific Hilbert space sectors characterized by particular magnetic fluxes. Furthermore, when subjected to twists by the electric 1-form global symmetry, these surviving sectors reveal an anomaly between the noninvertible and the 1-form symmetries. We argue that an anomaly implies that certain sectors, characterized by the eigenvalues of the electric symmetry generators, exhibit multi-fold degeneracies. When we couple these theories to axions, infrared axionic noninvertible operators inherit the ultraviolet structure of the theory, including the projective nature of the operators and their anomalies. We discuss various examples of vector and chiral gauge theories that showcase the versatility of our approach. [ABSTRACT FROM AUTHOR]

We review and extend the theory of ideal, homogeneous, incompressible, magnetohydrodynamic (MHD) turbulence. The theory contains a solution to the 'dynamo problem', i.e., the problem of determining how a planetary or stellar body produces a global dipole magnetic field. We extend the theory to the case of ideal MHD turbulence with a mean magnetic field that is aligned with a rotation axis. The existing theory is also extended by developing the thermodynamics of ideal MHD turbulence based on entropy. A mathematical model is created by Fourier transforming the MHD equations and dynamical variables, resulting in a dynamical system consisting of the independent Fourier coefficients of the velocity and magnetic fields. This dynamical system has a large but finite-dimensional phase space in which the phase flow is divergenceless in the ideal case. There may be several constants of the motion, in addition to energy, which depend on the presence, or lack thereof, of a mean magnetic field or system rotation or both imposed on the magnetofluid; this leads to five different cases of MHD turbulence that must be considered. The constants of the motion (ideal invariants)—the most important being energy and magnetic helicity—are used to construct canonical probability densities and partition functions that enable ensemble predictions to be made. These predictions are compared with time averages from numerical simulations to test whether or not the system is ergodic. In the cases most pertinent to planets and stars, nonergodicity is observed at the largest length-scales and occurs when the components of the dipole field become quasi-stationary and dipole energy is directly proportional to magnetic helicity. This nonergodicity is evident in the thermodynamics, while dipole alignment with a rotation axis may be seen as the result of dynamical symmetry breaking, i.e., 'broken ergodicity'. The relevance of ideal theoretical results to real (forced, dissipative) MHD turbulence is shown through numerical simulation. Again, an important result is a statistical solution of the 'dynamo problem'. [ABSTRACT FROM AUTHOR]

The characterization of small-size engines requires dedicated rigs that are usually used for loading the power unit. Adding the possibility of motoring the engine is an important advantage that allows more detailed information on operating characteristics. It can be used for obtaining precious data that contribute to the development of more accurate numerical models and subsequent validation. Cost competitiveness is another essential aspect of small-size engines, given that development efforts need to be contained as much as possible. Within this context, the present work developed and tested a setup capable of cranking and motoring a small-size 50 cc spark ignition engine. Two configurations were considered for coupling an electric motor to the power unit: the first through a pulley-belt transmission and the second via a plastic clutch assembly. The main idea was to ensure the capability of motoring the engine up to a rotational velocity of 6000 rpm. Engine load was applied through a 1 kW electric generator connected directly to the crankshaft. The overall setup was designed in the two configurations and a stress–strain analysis was performed. The belt-driven option was found to be more favorable in terms of mechanical component requirements, showing a safety factor of around 4.0, while the plastic clutch assembly involved a more complex design phase and turned out to be more demanding, with a safety factor of around 2.9. [ABSTRACT FROM AUTHOR]

Magnetic fields are now widely recognized as critical at many scales to galactic dynamics and structure, including multiphase pressure balance, dust processing, and star formation. Using imposed magnetic fields cannot reliably model the interstellar medium's (ISM) dynamical structure nor phase interactions. Dynamos must be modeled. ISM models exist of turbulent magnetic fields using small-scale dynamo (SSD). Others model the large-scale dynamo (LSD) organizing magnetic fields at the scale of the disk or spiral arms. Separately, neither can fully describe the galactic magnetic field dynamics nor topology. We model the LSD and SSD together at a sufficient resolution to use the low explicit Lagrangian resistivity required. The galactic SSD saturates within 20 Myr. We show that the SSD is quite insensitive to the presence of an LSD and is even stronger in the presence of a large-scale shear flow. The LSD grows more slowly in the presence of SSD, saturating after 5 Gyr versus 1–2 Gyr in studies where the SSD is weak or absent. The LSD primarily grows in warm gas in the galactic midplane. Saturation of the LSD occurs due to α -quenching near the midplane as the growing mean-field produces a magnetic α that opposes the kinetic α. The magnetic energy in our models of the LSD shows a slightly sublinear response to increasing resolution, indicating that we are converging toward the physical solution at 1 pc resolution. Clustering supernovae in OB associations increases the growth rates for both the SSD and the LSD, compared to a horizontally uniform supernova distribution. [ABSTRACT FROM AUTHOR]

With the rapid development of modern society, our demand for energy is increasing. And the extensive use of fossil energy has triggered a series of problems such as an energy crisis and environmental pollution. A moisture-enabled electric generator (MEG) is a new type of energy conversion method, which can directly convert the ubiquitous moisture in the air into electrical energy equipment. It has attracted great interest for its renewable and environmentally friendly qualities. At present, most MEGs still have low power density, strong dependence on high humidity, and high cost. Herein, we report the development of a high-efficiency MEG based on a lignocellulosic fiber frame with high-power-density, all-weather, and low-cost characteristics using a simple strategy that optimizes the charge transport channel and ion concentration difference. The MEG devices we manufactured can generate the open-circuit voltage of 0.73 V and the short-circuit current of 360 μA, and the voltage can still reach 0.6 V at less than 30% humidity. It is possible to drive commercial electronic devices such as light-emitting diodes, electronic displays, and electronic calculators by simply connecting several electric generators in series. Biomass-based moisture-enabled electric generation has a low cost, is easy to integrate on a large scale, and is green and pollution-free, providing clean energy for low-humidity or high-electricity-cost areas. [ABSTRACT FROM AUTHOR]

The reliance on imported fuels for electricity generation and internal transportation in insular electrical systems has historically posed a significant challenge due to their geographic isolation. The vulnerability of insular ecosystems to pollution has driven the need to transition toward renewable energy sources. Despite their inherent variability, wind and solar energy have gained acceptance. Integrating these renewable technologies into insular grids presents technical challenges that impact the quality of the power supply, particularly with the increasing presence of electric vehicles. Nevertheless, the batteries of these vehicles provide an opportunity to enhance network performance. This article introduces an innovative power smoothing technique that utilizes electric vehicle batteries to optimize self-consumption and reduce power fluctuations. The proposed method is an enhanced version of the ramp-rate energy smoothing method, incorporating adaptability through real-time control of the ramp-rate using fuzzy logic. It employs an aggregated model of lithium-ion batteries with a bidirectional power electronic converter. Experimental validation is carried out in the Micro-Grid Laboratory of the University of Cuenca, Ecuador. Experimental results demonstrate a significant 14% reduction in energy generation variability, resulting in a more stable electrical supply profile. Additionally, there is a marginal improvement in energy delivery, with an additional injection of 0.23 kWh compared to scenarios without the participation of electric vehicle batteries in power smoothing tasks. These findings support the effectiveness of the proposed approach in optimizing the integration of intermittent renewable generators and electric vehicle charging in insular energy systems. [ABSTRACT FROM AUTHOR]

We report on a first-principles numerical and theoretical study of plasma dynamo in a fully kinetic framework. By applying an external mechanical force to an initially unmagnetized plasma, we develop a self-consistent treatment of the generation of "seed" magnetic fields, the formation of turbulence, and the inductive amplification of fields by the fluctuation dynamo. Driven large-scale motions in an unmagnetized, weakly collisional plasma are subject to strong phase mixing, which leads to the development of thermal pressure anisotropy. This anisotropy triggers the Weibel instability, which produces filamentary "seed" magnetic fields on plasma-kinetic scales. The plasma is thereby magnetized, enabling efficient stretching and folding of the fields by the plasma motions and the development of Larmor-scale kinetic instabilities such as the firehose and mirror. The scattering of particles off the associated microscale magnetic fluctuations provides an effective viscosity, regulating the field morphology and turbulence. During this process, the seed field is further amplified by the fluctuation dynamo until energy equipartition with the turbulent flow is reached. By demonstrating that equipartition magnetic fields can be generated from an initially unmagnetized plasma through large-scale turbulent flows, this work has important implications for the origin and amplification of magnetic fields in the intracluster and intergalactic mediums. [ABSTRACT FROM AUTHOR]

We discuss the unique solvability of the inverse coefficient problem for the system of magnetic hydrodynamic equations, which describes the magnetic field generation processes of the planets that have dynamos. [ABSTRACT FROM AUTHOR]