Distortion Generation Research Articles

ВЛИЯНИЕ ИНВЕРТОРНОГО РЕЖИМА ЗАРЯДНЫХ СТАНЦИЙ ЭЛЕКТРОМОБИЛЕЙ НА КАЧЕСТВО ЭЛЕКТРОСНАБЖЕНИЯ ПОТРЕБИТЕЛЯ В ЭНЕРГОСИСТЕМЕ

Recently, issues of increasing the environmental friendliness of technological productions, increasing the exergetic component and energy saving issues have become particularly relevant. Therefore, when organizing and designing electrical supply systems, a more correct solution is the use of an inverter-battery backup power supply system. Such a system will ensure reliable and uninterrupted operation of consumers in the building. The paper considers the solution of the problem of designing the inverter mode of the power supply system for connecting the charging station of electric vehicles to the substation of the city of Novosibirsk. The connected charger of an electric vehicle, being a non-linear load, leads not only to an increase in the load on the power grid infrastructure, but can also be a source of power supply. They can also cause a deterioration in the quality of electricity due to the generation of harmonic distortion. Therefore, special attention is paid to the influence of the inverter mode of electric vehicle charging stations on the quality of power supply to the consumer in the power system. A simulation simulation of the charging station was performed using the MATLAB Simulink software package

Ni (II) doping induced lattice distortion in Zn3In2S6/BiOBr-OVs for boosting photocatalytic removal of antibiotics and Cr (Ⅵ) performance

Ni doping was used to create S-scheme heterojunction Ni-Zn3In2S6/BiOBr photocatalyst with an oxygen vacancy. This catalyst could remove both metronidazole and Cr (VI). The addition of Ni replaced Zn in the lattice of Zn3In2S6, inducing the generation of lattice distortion and increase the separation efficiency of charge carriers. For MNZ and Cr (VI), N-ZISB-2 (with 2 wt% Ni doping and 15 wt% BiOBr loading) demonstrated the best photocatalytic removal ability (MNZ: 99.31 %, Cr (VI): 99.83 %). The results of XRD and TEM indicated the successful substitution of Ni.The outcomes of XPS, UPS, and ESR demonstrated that the S-scheme heterojunction mechanism was followed by N-ZISB-x. Most intermediates of degradation had little ecological toxicity. In this work, we propose three potential routes for MNZ deterioration. XPS was used to confirm Cr (VI)'s reduction process. This investigation looked at the impact of oxygen vacancies and lattice distortion on photocatalytic performance.

Multivariable-incorporating super-resolution residual network for transcranial focused ultrasound simulation

Background and objective: Transcranial focused ultrasound (tFUS) has emerged as a new non-invasive brain stimulation (NIBS) modality, with its exquisite ability to reach deep brain areas at a high spatial resolution. Accurate placement of an acoustic focus to a target region of the brain is crucial during tFUS treatment; however, the distortion of acoustic wave propagation through the intact skull casts challenges. High-resolution numerical simulation allows for monitoring of the acoustic pressure field in the cranium but also demands extensive computational loads. In this study, we adopt a super-resolution residual network technique based on a deep convolution to enhance the prediction quality of the FUS acoustic pressure field in the targeted brain regions.Methods: The training dataset was acquired by numerical simulations performed at low-(1.0 mm) and high-resolutions (0.5mm) on three ex vivo human calvariae. Five different super-resolution (SR) network models were trained by using a multivariable dataset in 3D, which incorporated information on the acoustic pressure field, wave velocity, and localized skull computed tomography (CT) images.Results: The accuracy of 80.87±4.50% in predicting the focal volume with a substantial improvement of 86.91% in computational cost compared to the conventional high-resolution numerical simulation was achieved. The results suggest that the method can greatly reduce the simulation time without sacrificing accuracy and improve the accuracy further with the use of additional inputs.Conclusions: In this research, we developed multivariable-incorporating SR neural networks for transcranial focused ultrasound simulation. Our super-resolution technique may contribute to promoting the safety and efficacy of tFUS-mediated NIBS by providing on-site feedback information on the intracranial pressure field to the operator.

Redesign of a closed-loop high-speed facility to test distortion generators

Aircraft engine architectures are currently in the phase of a change to meet future market demands. Certain such novel architectures force engines to operate under distorted inflow conditions, which are undesirable during flight. It is important to characterize the effect of such inflow distortions in order to understand the impact on the performance of engine components. This paper discusses the design and development of a novel test-facility that has the capability to test combined total pressure and swirl distortion generators under desired flow conditions. The return duct of the high-speed closed-loop compressor rig R4 at the von Karman Institute for Fluid Dynamics (VKI) has been redesigned to incorporate a test-section where distortion generators can be tested and characterized. Thus, a compressor test-rig is modified to act also as a wind tunnel capable of testing distortion generators at engine-like conditions.

Surge margin monitoring of one turboshaft engine with inlet distortion

In order to explore the engine surge when inlet distortion index and engine surge margin, the relationship between the parameter characteristics of research engine surge, strengthen safety monitoring assessment engine, this paper designed a kind of a certain type of engine bench test surge monitoring system, and unstable flow field of a certain type of vortex axis engine working parameters for monitoring and analysis. In this paper, a plug-plate distortion generator is used to induce a surge engine, and the circumferential static pressure changes of the inlet and outlet of the engine, the axial compressor and the centrifugal compressor under different working conditions are obtained. The changes of circumferential unevenness and mean turbulence, the pressure ratio at working point and the converted air flow rate at working point are analyzed with the increase of the height of the plug-plate under different working conditions. The results show that the distortion index of the working point increases and the surge margin decreases with the increase of the height of the plug-plate at the same rotating speed. When the height of the plug-plate is similar, the higher the speed is, the greater the distortion index of the working point is, and the smaller the surge margin is.

Synthesis of high-voltage cathode material using the Taylor-Couette flow-based co-precipitation method.

LiNi0.5Mn1.5O4 (LNMO), a next-generation high-voltage battery material, is promising for high-energy-density and power-density lithium-ion secondary batteries. However, rapid capacity degradation occurs due to problems such as the elution of transition metals and the generation of structural distortion during cycling. Herein, a new LNMO material was synthesized using the Taylor-Couette flow-based co-precipitation method. The synthesized LNMO material consisted of secondary particles composed of primary particles with an octahedral structure and a high specific surface area. In addition, the LNMO cathode material showed less structural distortion and cation mixing as well as a high cyclability and rate performance compared with commercially available materials.

ESRGAN-DP: Enhanced super-resolution generative adversarial network with adaptive dual perceptual loss

The proposal of perceptual loss solves the over-smoothing problem of images caused by pixel-wise loss and improves the visual quality of the images, but it also inevitably produces a large number of artifacts and distortions in images. The reason for this phenomenon is that the perceptual features only rely on a single pre-trained visual geometry group (VGG) network, which results in the features of the image being unable to be fully extracted, thus limiting the reasoning ability of the model. To fundamentally reduce the generation of artifacts and distortions, this paper proposes the Dual Perceptual Loss (DP Loss). First, we improve the perceptual feature extraction method so that it no longer only extracts single-type VGG features. In addition, a residual network (ResNet) feature that has a complementary relationship with the VGG feature can also be extracted. Then, we propose a dynamic weighting method to eliminate the magnitude difference between perceptual losses. Finally, to obtain the excellent effect of image reconstruction, enhanced super-resolution generative adversarial network (ESRGAN) with strong learning capability is used in this paper to adapt the complexity of DP Loss. The abundant experimental studies and evaluations are conducted on benchmark datasets. Results are encouraging and better than those previously reported on these datasets. The code is available at https://github.com/Sunny6-6-6/ESRGAN-DP.

A new intake distortion design system for research

The intake distortion experiment is one of the important methods for aero-engine aerodynamic stability assessment. In this paper, in order to overcome the shortcomings of traditional design methods such as low accuracy in approximating the target distortion map and many experimental iterations, a design system is proposed to design the target map distortion network using Fluent based on the mapping relationship between screen distance and porous media. Finally, the steady-state total pressure test system is designed, and the physical design of the distortion generator and wind tunnel test are completed, with the error of distortion index of less than 1.5%. The test results show that the design system can simulate the distortion requirements with high accuracy and efficiency.

Stable attenuation-compensated reverse time migration and its application to land seismic data

Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation. To obtain high-resolution imaging results, these negative effects must be considered during reverse time migration (RTM). We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion terms. However, the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form, causing the numerical simulation to become unstable. This is due to the fact that the amplitude of the compensation grows exponentially with frequency. In order to achieve stable attenuation-compensated RTM, we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency band. Based on this modified analytic formula, we then derive an explicit time-space domain attenuation compensation extrapolation operator. Finally, the implementation procedure of stable attenuation-compensated RTM is presented. In addition to being simple to implement, the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise, which will further improve the imaging resolution. We use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuation-compensated RTM in improving imaging resolution in viscous media.

Effects of Inlet Swirl Distortion on a Multi-Stage Compressor with Inlet Guide Vanes and Stall Margin Enhancement Method

Inlet swirl distortion is generally considered as a type of velocity distortion, and inlet guide vanes (IGVs) are widely used in the multi-stage compressor of aero-engines to eliminate the tangential velocity of the swirl flow. However, few studies have explored whether there still exists some negative influence of inlet swirl distortion on the compressor, even after the installation of IGVs. Therefore, in this study, the influence of various types of inlet swirl distortions on a multi-stage compressor with the installation of IGVs is investigated. A swirl distortion generator installed in the inlet duct was designed to produce various types of swirl flow patterns. When the distortion intensity increased to some degree, there still existed a decrease in the compressive capability and an obvious additional efficiency loss. The inlet twin swirl distortion was accompanied by total pressure distortion, so even with the installation of IGVs, there was still a significantly negative influence on the performance of the multi-stage compressor, especially the stall margin. Subsequently, to improve the stall margin under inlet swirl distortion, the stall precursor-suppressed (SPS) casing treatment was installed in the first stage of the multi-stage compressor. It could enhance the stall margin of the compressor with no obvious change in the characteristic curves and no additional efficiency loss under various types of inlet swirl distortions, and its mechanism was verified by capturing the dynamic pressure characteristics.

Optical Filter-Less Photonic FMCW Radar for Multi-Target Detection

Frequency modulated continuous wave (FMCW) radar monitors the instantaneous frequency difference between the transmitted and the received signal to determine the time of flight which is proportional to the range. Modern radar system necessitates multispectral sensing to enhance detection capability and anti-jamming efficacy that encourages the evolution from conventional electrical solutions to photonics-enhanced solutions. Photonics offers wide-bandwidth signal generation, parallel processing, and low propagation distortion. Most photonic-assisted radar models are based on optical filters to select the reference and reflected waveform to mix at the photodiode, which limits the system functionality due to the inability to operate in different frequency bands. We propose an optical filter-less photonics-based de-chirp processing of frequency-modulated continuous-wave radar waveforms that overcomes the issue of carrier frequency tunability and agility. A theoretical analysis is performed, followed by simulation, and validated by experiment. The proposed model is experimentally tested for detecting targets at different distances ranging from 150 cm to 210 cm. The system is emulated to detect multiple targets (up to four), showing a range resolution of <15 cm, and signal processing enables the estimation of the widths of different sizes of the targets.

Numerical solutions for crack problems during elastomer forming

Generically, thermoset elastomers are often referred to as rubber. It is characterized by the chemical bonding between polymer chains. One of the important problems that plague elastomer manufacturing and rubber parts under service is cracks. Predicting the main factors affecting crack propagation trajectories during forming and after curing time is an important challenge. For this purpose, numerical analysis was implemented by using the commercial ABAQUS/CAE software package. A three-dimensional model was established to predict the important factors that affect this process. During the analysis, the effect of forming velocity and the amount of kinetic energy on the distortion of rubber material and crack propagation is explored in detail by using different forming punch velocities. The drop velocity of the upper insert (punch) on the rubber pad was taken as 10 m/s, 7 m/s, and 5 m/s, respectively. Consequently, while each forming velocity will generate different kinetic energy between the interaction surfaces, the change in crack behavior and the normal stress can be monitored in different positions. As a result, among these velocities, it was found that the low forming velocity of the upper insert (punch) is better than the others in forming rubber where cracks and distortions were at minimum values. Also, the amount of kinetic energy is low enough in the case of low speeds and can affect the results significantly. In addition, it was found that the generated stresses have a significant impact on the crack development in a specific area, especially near the fillets and sharp edges. It was concluded that calculating the parameters affecting the crack growth and predicting the crack propagation trajectories using the finite element method is a significant method for predicting and solving crack problems before tool fabrication

Power quality enhancement for charging station with moving window min–max algorithm based shunt active power filter

The widespread development of charging infrastructure is essential for the projected growth of electric vehicles. These charging stations are non-linear loads and necessitate shunt active power filters (SAPFs) to prevent the propagation of current distortions into the grid. Otherwise, the system efficiency and power transfer capability would reduce. This paper proposes control of SAPF with a moving window min–max (MWM) algorithm-based computation of the fundamental active component (FAC) of load current. The proposed algorithm computes FAC as the average of the maximum and minimum value of d-axis current over the period corresponding to its lowest order harmonic. The lowest harmonic is six and two for the balanced and unbalanced loading, respectively. Based on whether the currents are balanced or not, the MWM algorithm determines the width of the moving window where the minimum and maximum values are stored for computing FAC. The computational simplicity of this algorithm is evident from the pseudo-code presented. The experimental results show that the proposed method offers faster dynamic and accurate steady-state responses than the low pass filter-based synchronous reference frame method. Furthermore, analysis of SAPF operation with the proposed extraction scheme based on simulations reveals that the charging station operation complies with the power quality standards.

Atomistic mechanism for whole-field distortion of the substitutional solid solutions

The exploration of lattice distortion is of great significance to design and improve the substitutional solid solutions (SSSs). However, the distortion caused by substitution atoms is not well understood. We propose the atomistic mechanism and establish the corresponding theoretical framework that physically describes the distortion of general SSSs. The consideration is the local distortion propagates from the lattices containing substitution atoms to the bulks. Specifically, the local anisotropic lattice distortion is described by the atomic model based on the minimum energy principle, the non-uniform propagation of the local distortion is expressed by the one-dimension atomic chain model, and the whole-field distortion of SSSs is predicted by superimposing the distortion in the independent atomic chains. The framework is applied not only to predict the lattice constants, track each atoms equilibrium position, but also to estimate the distortion resistance of SSSs, and is validated via ab initio simulations of various SSSs with different types and contents substitution atoms. The research clarifies the origin mechanism and the universal laws of dilatation and lays the fundament for revealing the strengthening mechanism of SSSs.

A High-Precision Elastic Reverse-Time Migration for Complex Geologic Structure Imaging in Applied Geophysics

High-precision elastic reverse-time migration (ERTM) imaging has always been one of the trends in the development of geophysics. However, current wavefield simulations using time-domain finite-difference (FD) approaches in ERTM have second-order temporal accuracy, resulting in travel time changes and waveform distortion in wavefield propagation with large time steps, i.e., temporal dispersion. Errors caused by the temporal dispersion can lead to erroneous imaging locations and out-of-focus diffraction events. A new ERTM and its workflow are established here using temporal and spatial high-order FD accuracy wavefields and the vector-based imaging condition. Our method computes elastic vector-based wavefields by solving a P- and S-wave decomposition form of a quasi-stress–velocity equation. An advanced finite-difference scheme is employed in the wavefield solution to achieve simulation with temporal fourth-order accuracy and spatial arbitrary even-order accuracy. The normalized dot-product imaging condition of the source and receiver P/S wavefields is then applied to generate high-quality images. The elastic wavefield simulation and ERTM numerical examples presented here reveal that the anti-dispersion workflow can improve modeling and imaging accuracy. In addition, the field data application shows that our method can achieve reasonable and reliable ERTM images. This method can integrate the most advanced imaging techniques into this computational framework to improve imaging accuracy.

Effects of Splitting Airfoil’s Aspect Ratio on the Control of Separation and Loss Distribution in a Distortion Generator

The effects of aspect ratio (AR: opposite diameter to width) reduction on the total pressure loss distribution of horizontally arranged splitting airfoils are investigated experimentally and numerically. The array arrangement of airfoils is proposed as a novel distortion generator mechanism. The upgrade feasibility study of the single airfoil loss repeatability in combined pattern was the aim of the present research. Modification of 90° splitting airfoil as a representative of the airfoils category with AR &gt; 1 was a corrective approach to eliminate or delay the downstream wake axis rotation destructive effects on the combined loss predictability. The results of the modified airfoil (single and multiple arrangements) wake simulations based on hybrid turbulence model demonstrate a good agreement with wind tunnel measurements. It was observed that the aspect ratio reduction below the limiting value of “1” for selected opening angle provides the quasi-2D behavior of downstream flow structure related to AR &lt; 1 airfoil category along with relatively higher value of loss related to AR &gt; 1 category. Elimination of the side separation for modified 90° airfoil and the resulting similarity of maximum loss lobes positioning in arrangement of airfoils lead to the reduction of combined flow structure complexity and the improvement of loss predictability. It has appeared that combined loss pattern of the triple arrangement of the airfoils can be reconstructed from dual arrangement, and it can be reproduced from a single pattern in a hierarchical process. Concerning the maximum loss coefficient “values,” an overprediction of velocity recovery rate was observed in simulation results at the fully developed wake region that led to approximately 15% lower maximum loss values in comparison with the experiments.

Prominence of Filtering Techniques for Harmonics Mitigation in Advanced Power Electronics Systems

With the advancement in technology, non-linear loads, continue to increase, and the enigma of harmonics is getting more and more serious. The huge addition of electronic loads in power systems has formed the problem of harmonic generation that has resulted in many associated drawbacks. This paper aims to analyze the harmonics in advanced power electronics-based systems and describes a solution to mitigate them through two distinguished filtering techniques. A rigorous analysis is done concerning the generation of harmonic distortion through different types of loads and harmonic mitigation by employing passive and active power filters. The active power (adaptive) filtering method mitigates all sorts of undesirable frequency components using artificial intelligence (AI) based algorithms by calculating the weight of the fundamental component and generating a harmonics replica to subtract it from the original periodic wave. The simulations that were done show that the indicated techniques can mitigate undesirable harmonics and can lower the total harmonic distortion (THD) effectively according to the statutory limit of the IEEE 519-2014 standard, thus lowering the associated drawbacks of harmonic generation in advanced power electronics systems.

The archetypal molecular patterns of conscious experience are quantum analogs

We define quantum analogs as vibrational excitations of quasiparticles coupled to electromagnetically-mediated resonance energy transfer in water (a crystal lattice). This paper addresses how neural magnetic resonance spectra of the brain’s magnetic field influence dipolar oscillation waves in crystal lattices of interfacial water molecules to produce correlates of phenomenal consciousness. We explore dipolar oscillation waves in hydrophobic protein cavities of aromatic amino acids as a conduit for coherent propagation of vibrational excitation and hydrogen bond distortion associated with phase coherence present in the magnetic field intensity oscillations at a frequency at which the energy switches from its trapped form as excited phonon states to free, cavity-mode magnetic field energy states. A quasi-polaritons that reflect “hydro-ionic waves” is a macroscopic quantum effect of crystal lattice vibrations, consisting of vibron polaritons coupled to ions across the neocortex, except the cerebellum, due to the absence of protein-protein interactions. They are quantum-like at the core and hence can exhibit quantum-like signaling properties when resonant energy is transferred as dipolar waves in hydrophobic protein cavities of aromatic amino acids. This is due to aromatic residue flexibility in molecular electromagnetic resonances. Finally, the archetypal molecular patterning of conscious experiences, which carries an inherent ambiguity necessary for non-contextually applying ‘meaning’ that encompasses cognitive signatures of conscious experience, satisfies the nature of quantum analogs and their transmutative properties.

Numerical Simulation of Flow Field Structure of Flashboard Distortion Generator

In order to accurately analyze the characteristics of flashboard distortion generator, flow field with different structure and aerodynamic parameters was studied by numerical simulation.Then distribiton of Mach on the AIP interface behind the flashboard was analyzed, so as to guide the experiment design of the flashboard distortion generator. The results show that Mach distribution on the AIP interface is basically divided into three obvious regions. Mach transitions from high Mach to low Mach is in a small area. The average Mach of AIP interface increases slowly with the total pressure increasing, and decreases sharply with the increase of inserted depth. The angular vortex structure formed in the corner area where the flashboard meets the shell would extend downstream, so it is necessary to study the influence of angular vortex on compressor stability boundary.

Optical black hole characteristics using microring space‐time distortion circuit

AbstractAn optical black hole circuit designing and modeling using microring Kerr effect within the microring resonator system is proposed. An InGaAsP/InP material other than metamaterials are employed for optical black hole generation. The input sources are the space‐time function modulations, where the resonant space‐time distortion of the electric field propagation through the circuit can be arranged to meet the balanced optical path differences. The nonlinearr Kerr effect can be generated by the two side rings and induced into the center ring. The optical black hole circuit characteristics are investigated from the event horizon to the singularity area, where the potential for a high‐performance light absorber can be envisaged. In applications, the device can be employed in photovoltaics and quantum technology.