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36 pages, 2856 KiB  
Review
Intertwined Orders and the Physics of High Temperature Superconductors
by Eduardo Fradkin
Particles 2025, 8(3), 70; https://doi.org/10.3390/particles8030070 - 23 Jul 2025
Viewed by 174
Abstract
Complex phase diagrams are a generic feature of quantum materials that display high-temperature superconductivity. In addition to d-wave superconductivity (or other unconventional states), these phase diagrams typically include various forms of charge-ordered phases, including charge-density waves and/or spin-density waves, as well as electronic [...] Read more.
Complex phase diagrams are a generic feature of quantum materials that display high-temperature superconductivity. In addition to d-wave superconductivity (or other unconventional states), these phase diagrams typically include various forms of charge-ordered phases, including charge-density waves and/or spin-density waves, as well as electronic nematic states. In most cases, these phases have critical temperatures comparable in magnitude to that of the superconducting state and appear in a “pseudo-gap” regime. In these systems, the high temperature state does not produce a good metal with well-defined quasiparticles but a ”strange metal”. These states typically arise from doping a strongly correlated Mott insulator. With my collaborators, I have identified these behaviors as a problem with “Intertwined Orders”. A pair-density wave is a type of superconducting state that embodies the physics of intertwined orders. Here, I discuss the phenomenology of intertwined orders and the quantum materials that are known to display these behaviors. Full article
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32 pages, 3242 KiB  
Article
A Data-Driven Bayesian Belief Network Influence Diagram Approach for Socio-Environmental Risk Assessment and Mitigation in Major Ecosystem- and Landscape-Modifier Projects
by Salim Ullah Khan, Qiuhong Zhao, Muhammad Wisal, Kamran Ali Shah and Syed Shahid Shah
Sustainability 2025, 17(8), 3537; https://doi.org/10.3390/su17083537 - 15 Apr 2025
Cited by 1 | Viewed by 732
Abstract
Infrastructure projects that transform ecosystems and landscapes, such as hydropower developments, are essential for economic growth but pose significant socio-environmental challenges. Addressing these complexities requires advanced, dynamic management strategies. This study presents the Bayesian integrated risk mitigation model (BIRMM), a novel probabilistic framework [...] Read more.
Infrastructure projects that transform ecosystems and landscapes, such as hydropower developments, are essential for economic growth but pose significant socio-environmental challenges. Addressing these complexities requires advanced, dynamic management strategies. This study presents the Bayesian integrated risk mitigation model (BIRMM), a novel probabilistic framework designed to augment traditional environmental impact assessments. BIRMM enables comprehensive risk evaluation, scenario-based analysis, and mitigation planning, empowering stakeholders to make informed decisions throughout project lifecycles. BIRMM integrates socio-environmental and economic risks using a three-dimensional risk assessment approach grounded in a Bayesian belief network influence diagram. It provides a holistic view of risk interactions by capturing interdependencies across spatial, temporal, and magnitude dimensions. Through simulation of risk dynamics and adaptive evaluation of mitigation strategies, BIRMM offers actionable insights for resource allocation, enhancing project resilience, and minimizing socio-environmental disruptions. The framework was validated using the Balakot Hydropower Project in Pakistan. BIRMM successfully simulated proposed risks and assessed mitigation strategies under varying scenarios, demonstrating its reliability in navigating complex socio-environmental challenges. The case study highlighted its potential to support adaptive decision-making across all project phases. With its versatility and practical ease, BIRMM is particularly suited for large-scale energy, transportation, and urban development projects. By bridging gaps in traditional methodologies, BIRMM advances sustainable development practices, promotes equitable stakeholder outcomes, and establishes itself as an indispensable decision-support tool for modern infrastructure projects. Full article
(This article belongs to the Collection Risk Assessment and Management)
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12 pages, 4054 KiB  
Article
Low-Frequency Communication Based on Rydberg-Atom Receiver
by Yipeng Xie, Mingwei Lei, Jianquan Zhang, Wenbo Dong and Meng Shi
Electronics 2025, 14(5), 1041; https://doi.org/10.3390/electronics14051041 - 6 Mar 2025
Viewed by 1034
Abstract
Rydberg-atom receivers have developed rapidly with increasing sensitivity. However, studies on their application in low-frequency electric fields remain limited. In this work, we demonstrate low-frequency communication using an electrode-embedded atom cell and a whip antenna without the need for a low-noise amplifier (LNA). [...] Read more.
Rydberg-atom receivers have developed rapidly with increasing sensitivity. However, studies on their application in low-frequency electric fields remain limited. In this work, we demonstrate low-frequency communication using an electrode-embedded atom cell and a whip antenna without the need for a low-noise amplifier (LNA). Three modulations—binary phase-shift keying (BPSK), on–off keying (OOK), and two-frequency shift keying (2FSK)—were employed for communication using a Rydberg-atom receiver operating near 100 kHz. The signal-to-noise ratio (SNR) of the modulated low-frequency signal received by Rydberg atoms was measured at various emission voltages. Additionally, we demonstrated the in-phase and quadrature (IQ) constellation diagram, error vector magnitude (EVM), and eye diagram of the demodulated signal at different symbol rates. The EVM values were measured to be 8.8% at a symbol rate of 2 kbps, 9.4% at 4 kbps, and 13.7% at 8 kbps. The high-fidelity digital color image transmission achieved a peak signal-to-noise ratio (PSNR) of 70 dB. Our results demonstrate the feasibility of a Rydberg-atom receiver for low-frequency communication applications. Full article
(This article belongs to the Topic Quantum Wireless Sensing)
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17 pages, 7389 KiB  
Article
Quadruple-Q Skyrmion Crystal in Centrosymmetric Body-Centered Tetragonal Magnets
by Satoru Hayami
Magnetism 2025, 5(1), 2; https://doi.org/10.3390/magnetism5010002 - 17 Jan 2025
Viewed by 1950
Abstract
We conduct a numerical investigation into the stability of a quadruple-Q skyrmion crystal, a structure generated by the superposition of four spin density waves traveling in distinct directions within three-dimensional space, hosted on a centrosymmetric body-centered tetragonal lattice. Using simulated annealing applied [...] Read more.
We conduct a numerical investigation into the stability of a quadruple-Q skyrmion crystal, a structure generated by the superposition of four spin density waves traveling in distinct directions within three-dimensional space, hosted on a centrosymmetric body-centered tetragonal lattice. Using simulated annealing applied to an effective spin model that includes momentum-resolved bilinear and biquadratic interactions, we construct a magnetic phase diagram spanning a broad range of model parameters. Our study finds that a quadruple-Q skyrmion crystal does not emerge within the phase diagram when varying the biquadratic interaction and external magnetic field. Instead, three distinct quadruple-Q states with topologically trivial spin textures are stabilized. However, we demonstrate that the quadruple-Q skyrmion crystal can become the ground state when an additional high-harmonic wave–vector interaction is considered. Depending on the magnitude of this interaction, we obtain two types of quadruple-Q skyrmion crystals exhibiting the skyrmion numbers of one and two. These findings highlight the emergence of diverse three-dimensional multiple-Q spin states in centrosymmetric body-centered tetragonal magnets. Full article
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23 pages, 8405 KiB  
Article
The Concept of the Estimation of Phase Diagrams (An Optimised Set of Simplified Equations to Estimate Equilibrium Liquidus and Solidus Temperatures, Partition Ratios, and Liquidus Slopes for Quick Access to Equilibrium Data in Solidification Software) Part I: Binary Equilibrium Phase Diagrams
by Gergely Kőrösy, András Roósz and Tamás Mende
Metals 2024, 14(11), 1266; https://doi.org/10.3390/met14111266 - 7 Nov 2024
Cited by 1 | Viewed by 1482
Abstract
This paper presents equations derived from thermodynamic equations for calculating the liquidus and solidus temperatures, the liquidus slope, and the partition ratio for solidification simulations. The constants of these equations can be easily determined from measurement data obtained by digitalisation from known diagrams [...] Read more.
This paper presents equations derived from thermodynamic equations for calculating the liquidus and solidus temperatures, the liquidus slope, and the partition ratio for solidification simulations. The constants of these equations can be easily determined from measurement data obtained by digitalisation from known diagrams or can be calculated using a CALPHAD-based software. ESTPHAD has a hierarchical system; the developed functions of the binary systems are used in the calculation of the functions of the ternary systems, the functions of the ternary systems in the calculation of the function of quaternary systems, and so on. The developed method is demonstrated by processing the liquidus and solidus of Si–Ge isomorphous and Al–Mg and Al–Si eutectic equilibrium phase diagrams. The use of this method for calculating the functions of ternary systems will be shown in Part II. The advantages of this method are that the equations are simple, can be determined very quickly, and can be built into the simulation software very easily. The most significant advantage is that the calculation time is shorter by some order of magnitude than that of a CALPHAD-type calculation. Full article
(This article belongs to the Special Issue Thermodynamic Assessment of Alloy Systems)
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22 pages, 1315 KiB  
Article
The Ordered Structures Formed by Janus-like Particles on a Triangular Lattice
by Andrzej Patrykiejew
Molecules 2024, 29(21), 5215; https://doi.org/10.3390/molecules29215215 - 4 Nov 2024
Viewed by 1194
Abstract
The formation of ordered structures by Janus-like particles, composed of two parts (A and B), with orientation-dependent interactions on a triangular lattice was studied using Monte Carlo methods. The assumed lattice model allows each particle to take on one of the six orientations. [...] Read more.
The formation of ordered structures by Janus-like particles, composed of two parts (A and B), with orientation-dependent interactions on a triangular lattice was studied using Monte Carlo methods. The assumed lattice model allows each particle to take on one of the six orientations. The interaction between the A parts of neighboring particles was assumed to be attractive, while the AB and BB interactions were assumed to be repulsive. Moreover, it was assumed that the interaction between a pair of neighboring particles depended on the degrees to which their AA, AB, and BB parts face each other. It was shown that several ordered phases of different densities and structures may appear, depending on the magnitudes of AB and BB interactions. In particular, we found several structures composed of small clusters consisting of three (OT), four (OR), and seven (S) particles, surrounded by empty sites, the lamellar phases (OL, OL1, and OL3), the structures with hexagonal symmetry (R3×3 and K), as well as the structures with more complex symmetry (R5×5 and LAD). Several phase diagrams were evaluated, which demonstrated that the stability regions of different ordered phases are primarily determined by the strengths of repulsive AB and BB interactions. Full article
(This article belongs to the Special Issue Exclusive Feature Papers in Physical Chemistry, 2nd Edition)
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16 pages, 4790 KiB  
Article
Deterministic and Stochastic Analysis of Fractional-Order Legendre Filter with Uncertain Parameters
by Mohammed A. Hassan, Andrew Amgad and Osama H. Galal
Fractal Fract. 2024, 8(11), 645; https://doi.org/10.3390/fractalfract8110645 - 31 Oct 2024
Viewed by 824
Abstract
Fractional order filters are increasingly used due to their flexibility and continuous stepped stopband attenuation rate. The current work presents a deterministic design plan for an optimal fractional-order Legendre low-pass filter along with a stochastic investigation of its parametric uncertainty. First, the filter’s [...] Read more.
Fractional order filters are increasingly used due to their flexibility and continuous stepped stopband attenuation rate. The current work presents a deterministic design plan for an optimal fractional-order Legendre low-pass filter along with a stochastic investigation of its parametric uncertainty. First, the filter’s order was determined using the provided parameters, then the flower pollination algorithm was used to tune the transfer function parameters. This method uses the phase delay and magnitude response functions to quantify the desired output. Circuit diagrams, LT spice simulations, and a case study were used to validate the method. In addition, the effects of various components on stability and the performance metrics were further examined. Next, each of the described fractional system parameters (R1, R2, the ratio R4R3, Cα, and Cβ) was modeled as an uncertain term in a distinct cases, referred to as Cases I–V, respectively, and their combined effect was investigated as Case VI. These uncertain parameters were implemented using both random variables and stochastic processes. The system response was assessed using the Monte Carlo simulation method, and the mean, standard deviation, probability density function, and lower and upper bounds were plotted. Additionally, the key statistics of the cutoff frequency were tabulated in all cases. Many findings are addressed by the provided system solutions; briefly, the results revealed that the impact of uncertainty cases on system response, in descending order, was Case VI, Case III, Case V, Case II, Case I, and Case IV. Furthermore, the system demonstrated instability in Cases III and VI, which drew the designers’ attention to these two cases. Full article
(This article belongs to the Section Engineering)
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19 pages, 6658 KiB  
Article
A Three-Level Neutral-Point-Clamped Converter Based Standalone Wind Energy Conversion System Controlled with a New Simplified Line-to-Line Space Vector Modulation
by Tarak Ghennam, Lakhdar Belhadji, Nassim Rizoug, Bruno Francois and Seddik Bacha
Energies 2024, 17(9), 2214; https://doi.org/10.3390/en17092214 - 4 May 2024
Cited by 1 | Viewed by 1591
Abstract
Wind power systems, which are currently being constructed for the electricity worldwide market, are mostly based on Doubly Fed Induction Generators (DFIGs). To control such systems, multilevel converters are increasingly preferred due to the well-known benefits they provide. This paper deals with the [...] Read more.
Wind power systems, which are currently being constructed for the electricity worldwide market, are mostly based on Doubly Fed Induction Generators (DFIGs). To control such systems, multilevel converters are increasingly preferred due to the well-known benefits they provide. This paper deals with the control of a standalone DFIG-based Wind Energy Conversion System (WECS) by using a three-level Neutral-Point-Clamped (NPC) converter. The frequency and magnitude of the stator output voltage of the DFIG are controlled and fixed at nominal values despite the variable rotor speed, ensuring a continuous AC supply for three-phase loads. This task is achieved by controlling the DFIG rotor currents via a PI controller combined with a new Simplified Direct Space Vector Modulation strategy (SDSVM), which is applied to the three-level NPC converter. This strategy is based on the use of a line-to-line three-level converter space vector diagram without using Park transformation and then simplifying it to that of a two-level converter. The performance of the proposed SDSVM technique in terms of controlling the three-level NPC-converter-based standalone WECS is demonstrated through simulation results. The whole WECS control and the SDSVM strategy are implemented on a dSPACE DS 1104 board that drives a DFIG-based wind system test bench. The obtained experimental results confirm the validity and performance in terms of control. Full article
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13 pages, 6548 KiB  
Article
Chiral Modulations in Non-Heisenberg Models of Non-Centrosymmetric Magnets Near the Ordering Temperatures
by Andrey O. Leonov
Magnetism 2024, 4(2), 91-103; https://doi.org/10.3390/magnetism4020007 - 1 Apr 2024
Viewed by 1587
Abstract
The structure of skyrmion and spiral solutions, investigated within the phenomenological Dzyaloshinskii model of chiral magnets near the ordering temperatures, is characterized by the strong interplay between longitudinal and angular order parameters, which may be responsible for experimentally observed precursor effects. Within the [...] Read more.
The structure of skyrmion and spiral solutions, investigated within the phenomenological Dzyaloshinskii model of chiral magnets near the ordering temperatures, is characterized by the strong interplay between longitudinal and angular order parameters, which may be responsible for experimentally observed precursor effects. Within the precursor regions, additional effects, such as pressure, electric fields, chemical doping, uniaxial strains and/or magnetocrystalline anisotropies, modify the energetic landscape and may even lead to the stability of such exotic phases as a square staggered lattice of half-skyrmions, the internal structure of which employs the concept of the “soft” modulus and contains points with zero modulus value. Here, we additionally alter the stiffness of the magnetization modulus to favor one- and two-dimensional modulated states with large modulations of the order parameter magnitude. The computed phase diagram, which omits any additional effects, exhibits stability pockets with a square half-skyrmion lattice, a hexagonal skyrmion lattice with the magnetization in the center of the cells parallel to the applied magnetic field, and helicoids with propagation transverse to the field, i.e., those phases in which the notion of localized defects is replaced by the picture of a smooth but more complex tiling of space. We note that the results can be adapted to metallic glasses, in which the energy contributions are the same and originate from the inherent frustration in the models, and chiral liquid crystals with a different ratio of elastic constants. Full article
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24 pages, 7048 KiB  
Article
Estimation of an Extent of Sinusoidal Voltage Waveform Distortion Using Parametric and Nonparametric Multiple-Hypothesis Sequential Testing in Devices for Automatic Control of Power Quality Indices
by Aleksandr Kulikov, Pavel Ilyushin, Aleksandr Sevostyanov, Sergey Filippov and Konstantin Suslov
Energies 2024, 17(5), 1088; https://doi.org/10.3390/en17051088 - 24 Feb 2024
Cited by 1 | Viewed by 1268
Abstract
Deviations of power quality indices (PQI) from standard values in power supply systems of industrial consumers lead to defective products, complete shutdown of production processes, and significant damage. At the same time, the PQI requirements vary depending on the industrial consumer, which is [...] Read more.
Deviations of power quality indices (PQI) from standard values in power supply systems of industrial consumers lead to defective products, complete shutdown of production processes, and significant damage. At the same time, the PQI requirements vary depending on the industrial consumer, which is due to different kinds, types, and composition of essential electrical loads. To ensure their reliable operation, it is crucial to introduce automatic PQI control devices, which evaluate the extent of distortion of the sinusoidal voltage waveform of a three-phase system. This allows the power dispatchers of grid companies and industrial enterprises to quickly make decisions on the measures to be taken in external and internal power supply networks to ensure that the PQI values are within the acceptable range. This paper proposes the use of an integrated indicator to assess the extent of distortion of the sinusoidal voltage waveform in a three-phase system. This indicator is based on the use of the magnitude of the ratio of complex amplitudes of the forward and reverse rotation of the space vector. In the study discussed, block diagrams of algorithms and flowcharts of automatic PQI control devices are developed, which implement parametric and nonparametric multiple-hypothesis sequential analysis using an integrated indicator. In this case, Palmer’s algorithm and the nearest neighbor method are used. The calculations demonstrate that the developed algorithms have high speed and high performance in detecting deviations of the electrical power quality. Full article
(This article belongs to the Topic Intelligent Control in Smart Energy Systems)
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18 pages, 3351 KiB  
Article
Multiphysics Study of Thermal Profiles and Residual Stress in Welding
by Yousung Han
Materials 2024, 17(4), 886; https://doi.org/10.3390/ma17040886 - 14 Feb 2024
Cited by 7 | Viewed by 1752
Abstract
One of the effects of welding is residual stress. Welding involves complex tests concerning differences in values of the mechanical parameters of its regions as an effect of residual stress. Such multiphysics characteristics of welding pose a challenge in predicting residual stress. In [...] Read more.
One of the effects of welding is residual stress. Welding involves complex tests concerning differences in values of the mechanical parameters of its regions as an effect of residual stress. Such multiphysics characteristics of welding pose a challenge in predicting residual stress. In the present study, a thermo-mechanical constitutive model considering phase transformation and transformation plasticity is implemented in the numerical model in ABAQUS user subroutines. In order to consider phase evolution in welding, the metallurgical parameters for Leblond’s phase equation were obtained from the calibration of DH36 steel with a CCT diagram. In addition, the effects of welding speed on thermal profiles and residual stress generation were investigated. Analysis has suggested that the width of the heat-affected zone (HAZ) decreases with an increase in welding speed, and the phase fraction is significantly affected by this kind of parameter. Such phase transformation has led to the generation of a compressive stress in the fusion zone (FZ) and HAZ. The volume difference between coexisting phases produces a compressive stress in cooling, and its magnitude was increased with martensite increasing. Full article
(This article belongs to the Special Issue Welding and Joining Processes of Metallic Materials)
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12 pages, 452 KiB  
Article
Tunable Josephson Current through a Semiconductor Quantum Dot Hybridized to Majorana Trijunction
by Yumei Gao and Xiaoyan Zhang
Coatings 2023, 13(9), 1627; https://doi.org/10.3390/coatings13091627 - 17 Sep 2023
Cited by 4 | Viewed by 1417
Abstract
We investigate theoretically the Josephson current through one semiconductor quantum dot (QD) coupled to triple nanowires (junctions) with Majorana bound states (MBSs) prepared at their ends. We find that not only the strength but also the period of the Josephson current flowing between [...] Read more.
We investigate theoretically the Josephson current through one semiconductor quantum dot (QD) coupled to triple nanowires (junctions) with Majorana bound states (MBSs) prepared at their ends. We find that not only the strength but also the period of the Josephson current flowing between the left and right Josephson junctions via the dot can be fully controlled in terms of the third junction side-coupled to the QD. When the phase factor is zero in the third junction, which acts as a current regulator, the Josephson current is a 2π-period function of the difference in phases of the left and right junctions. Now, the magnitude of the current is suppressed by hybridization between the QD and the regulator junction. The period of the current becomes 4π under the condition of nonzero phase factor in the regular junction, and thus either the magnitude or the sign (flow direction) of the current can be controlled in this trijunction device. This is difficult to realize in the usual tow-terminal structure. It is also found that the direct overlap between the MBSs in the regulator junction generally enhances the current’s amplitude, but those in the left and right Majorana junctions suppress the current. The above results are explained with the help of the device’s energy diagram and the current carrying density of states (CCDOS) and might be applied for adjusting the current density in the superconducting coated conductors technologies. Full article
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17 pages, 14856 KiB  
Article
Simulations and Experiments on the Microstructure and Property Evolution of In Situ TiC+Al3Ti-Reinforced Aluminum Coatings on AZ91D Magnesium Alloy
by Liuqing Yang, Zhiyong Li, Boqiong Li, Yingqiao Zhang, Shouzheng Wei and Yanlong Jia
Crystals 2023, 13(7), 1151; https://doi.org/10.3390/cryst13071151 - 24 Jul 2023
Cited by 4 | Viewed by 1582
Abstract
With the development of computational thermodynamics, it is possible to design a material based on its simulated microstructure and properties before practical operations. In order to improve the surface properties of AZ91D magnesium alloy, Jmatpro was used in this study to design an [...] Read more.
With the development of computational thermodynamics, it is possible to design a material based on its simulated microstructure and properties before practical operations. In order to improve the surface properties of AZ91D magnesium alloy, Jmatpro was used in this study to design an alloy system with in situ TiC+AlTi3-reinforced aluminum coatings. The Gibbs free energy, hardness, and phase diagrams of aluminum coatings with different ratios of Ti to B4C were simulated. According to the simulation results, TiB2, TiC, Al3Ti_DO22, and Al4C3 were formed in the coating while TiB2, TiC, Al3Ti_DO22, Al4C3, and Al3Mg2 were formed in the transition zone between the base metal and the coating. Based on the simulation results, different amounts of Ti were used with B4C (the ratios were 3:1, 4:1, 5:1, and 6:1) to fabricate TiC+Al3Ti reinforced aluminum coatings on AZ91D magnesium alloy via laser cladding. The microstructure and phase composition of the coating were studied using scanning electron microscopy (SEM) incorporated with energy- dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results indicated that intermetallic phases, such as AlTi3(C, N)0.6, AlMg, Al3Mg2, Al3Ti, and TiC were formed in the coatings. As the Ti content increased, the content of Al3Ti increased and the content of TiC decreased in the coatings, which is consistent with the simulation results. The average hardness of the coatings was approximately four to five times that of the magnesium alloy substrate, and the corrosion current density of the coatings was around 2.5 × 10−6, which is two orders of magnitude lower than that of AZ91D magnesium alloy. Full article
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26 pages, 13664 KiB  
Article
Assessment and Commissioning of Electrical Substation Grid Testbed with a Real-Time Simulator and Protective Relays/Power Meters in the Loop
by Emilio C. Piesciorovsky, Raymond Borges Hink, Aaron Werth, Gary Hahn, Annabelle Lee and Yarom Polsky
Energies 2023, 16(11), 4407; https://doi.org/10.3390/en16114407 - 30 May 2023
Cited by 9 | Viewed by 3125
Abstract
Electrical utility substations are wired with intelligent electronic devices (IEDs), such as protective relays, power meters, and communication switches. Substation engineers commission these IEDs to assess the appropriate measurements for monitoring, control, power system protection, and communication applications. Like real electrical utility substations, [...] Read more.
Electrical utility substations are wired with intelligent electronic devices (IEDs), such as protective relays, power meters, and communication switches. Substation engineers commission these IEDs to assess the appropriate measurements for monitoring, control, power system protection, and communication applications. Like real electrical utility substations, complex electrical substation grid testbeds (ESGTs) need to be assessed for measuring current and voltage signals in monitoring, power system protection, control (synchro check), and communication applications that are limited by small-measurement percentage errors. In the process of setting an ESGT with real-time simulators and IEDs in the loop, protective relays, power meters, and communication devices must be commissioned before running experiments. In this study, an ESGT with IEDs and distributed ledger technology was developed. The ESGT with a real-time simulator and IEDs in the loop was satisfactorily assessed and commissioned. The commissioning and problem-solving tasks of the testbed are described to define a method with flowcharts to assess possible troubleshooting in ESGTs. This method was based on comparing the simulations versus IED measurements for the phase current and voltage magnitudes, three-phase phasor diagrams, breaker states, protective relay times with selectivity coordination at electrical faults, communication data points, and time-stamp sources. Full article
(This article belongs to the Section F: Electrical Engineering)
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17 pages, 3954 KiB  
Article
Amplitude and Phase Angle of Oscillatory Heat Transfer and Current Density along a Nonconducting Cylinder with Reduced Gravity and Thermal Stratification Effects
by Zia Ullah, Nawishta Jabeen and Muhammad Usman Khan
Mathematics 2023, 11(9), 2134; https://doi.org/10.3390/math11092134 - 2 May 2023
Cited by 17 | Viewed by 2018
Abstract
Due to excessive heating, various physical mechanisms are less effective in engineering and modern technologies. The aligned electromagnetic field performs as insulation that absorbs the heat from the surroundings, which is an essential feature in contemporary technologies, to decrease high temperatures. The major [...] Read more.
Due to excessive heating, various physical mechanisms are less effective in engineering and modern technologies. The aligned electromagnetic field performs as insulation that absorbs the heat from the surroundings, which is an essential feature in contemporary technologies, to decrease high temperatures. The major goal of the present investigation is to use magnetism perpendicular to the surface to address this issue. Numerical simulations have been made of the MHD convective heat and amplitude problem of electrical fluid flow down a horizontally non-magnetized circular heated cylinder with reduced gravity and thermal stratification. The associated non-linear PDEs that control fluid motion can be conveniently represented using the finite-difference algorithm and primitive element substitution. The FORTRAN application was used to compute the quantitative outcomes, which are then displayed in diagrams and table formats. The physical features, including the phase angle, skin friction, transfer of heat, and electrical density for velocity description, the magnetic characteristics, and the temperature distribution, coupled by their gradients, have an impact on each of the variables in the flow simulation. In the domains of MRI resonant patterns, prosthetic heartvalves, interior heart cavities, and nanoburning devices, the existing magneto-hydrodynamics and thermodynamic scenario are significant. The main findings of the current work are that the dimensionless velocity of the fluid increases as the gravity factor Rg decreases. The prominent change in the phase angle of current density αm and heat flux αt is examined for each value of the buoyancy parameter at both α=π/6 and π angles. The transitory skin friction and heat transfer rate shows a prominent magnitude of oscillation at both α=π/6 and π/2 positions, but current density increases with a higher magnitude of oscillation. Full article
(This article belongs to the Special Issue Advances in Computational Fluid Dynamics with Applications)
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