In this article, we propose a novel super-resolution method for ultrawideband radar imaging, to address the problem of degraded range estimation accuracy of off-grid targets. We propose generalized atomic norm minimization (ANM) with modality demixing, dubbed ANM-MD, which effectively harnesses the sparsity of radar targets over a continuous range space. First, we demix the radar echo of targets according to their frequency dependency modalities (FDMs) in the geometrical theory of diffraction model. By modality demixing, we can suppress the influence of multiple FDMs on consequent estimation of target ranges. Then, we estimate the scattering parameters of radar targets separately in each FDM, leading to accurate estimation of target ranges. Experimental results show that our method can improve the accuracy of range estimation of off-grid targets by more than 15% compared with existing methods, leading to improved quality of super-resolution imaging.
A data-driven intelligent substation virtual loop automatic generation and independent verification method is proposed. The virtual connection information of the historical substation configuration description (CD) file is rapidly extracted by using the document object model (DOM) method，and the historical SCD database is constructed. The precise matching of the information of the intelligent electronic (IED) to be designed and the historical IED information is realized，and then the automatic generation scheme of the virtual connection is proposed. In view of the problems ofconnection and missed connection in practical application，the standard template library is constructed to verify the virtual connection generated automatically，and the visualization technology is used to realize the alarm，reminding the to add and modify the virtual connection. The correctness of the proposed method is verified based on an actual intelligent substation case.
Electricity, Production of electric energy or power. Powerplants. Central stations
Pancreatic health is closely linked to diabetes, making accurate fat quantification crucial for early diagnosis. This study proposes a deep learning-based method for automatic pancreatic segmentation and fat quantification. The nnU-Net model achieves high-precision segmentation on m-Dixon Imaging, with a Dice similarity coefficient (DSC) of 0.92. A novel sub-region partitioning and quantification method enables precise delineation of the pancreatic head, body, and tail. Analysis of 256 subjects (healthy, prediabetic, diabetic) reveals a significant association between pancreatic tail fat and type 2 diabetes (p < 0.05). Using random forest classifiers, diabetes risk was effectively predicted based on tail fat content and a composite fat index, yielding an area under the curve (AUC) of 0.68 and 0.73, respectively. This method offers a promising tool for the early diagnosis of diabetes.
This work presents a compact, low-cost hexa-band microstrip antenna for Internet of Things (IoT) applications. The proposed hexa-band antenna is composed of simple six-λ/4 resonators to generate six resonant frequencies: GSM 1.84 GHz (1.8 –1.89 GHz), Bluetooth 2.31 GHz (2.25 –2.375 GHz), WiMAX 3.3 GHz (3.16 –3.47 GHz), WiFi 4.63 GHz (4.34 –5 GHz), upper WLAN 6.1 GHz (5.8 –6.91 GHz), and X-band 9.26 GHz (8.87 –9.83 GHz). The proposed hexa-band antenna is fabricated using FR4 substrate with (23 × 20 × 1.6) mm3 dimensions, and its measured results are presented to validate the simulated results. Results from simulations and measurements are used to examine the radiation properties, including radiation patterns, gain, efficiency, VSWR, and reflection coefficient. The proposed hexa-band antenna has a miniaturized size and good radiation performance.
In order to reduce the carbon emission level of gas turbines and improve their flexibility, this paper proposes a low-carbon economic optimization strategy for the integrated energy system that takes into account oxy-fuel combustion carbon capture technology and source-load bilateral response. Firstly, the operating principle and energy flow characteristics of oxy-fuel combustion technology were studied, and a coupling model of air separation oxygen production equipment and carbon capture equipment was constructed. Secondly, the adjustable heat-to-power ratio was introduced as a supply-side response strategy, and a comprehensive trade-off was made for the demand-side between the characteristics of electricity, heat energy and gas load, and a demand-side response mechanism was formed with the guidance of energy prices and considering their substitutable attributes with each other. Finally, through constraining the carbon emissions by tiered carbon trading with consideration of carbon emissions of gas load, the units output in each period was optimized with the system operating cost as the objective. Multiple scenarios were set up for simulation analysis, and the results show that the oxy-fuel combustion carbon capture technology can effectively reduce the carbon emissions of the system, and the source-load bilateral response can flexibly adjust the energy supply relationship between the supply side and the demand side, and effectively reduce the operating cost of the system.
Electricity, Production of electric energy or power. Powerplants. Central stations
In this research, we present an innovative method for estimating the beams of array antennas. Traditional beam analysis methods rely on placing receiving antennas in the far-field region, which requires moving or rotating the Tx or Rx, and using radiation pattern measurements. However, such methods often demand vast spatial requirements and the use of high-cost network analyzers. In contrast, the technique proposed in this study utilizes a board patterned with coupling lines strategically placed in the antenna’s near-field zone. Signals intercepted by these coupling lines undergo conversion into DC voltage via a power detector situated at the line terminus. Interestingly, this method enables beam estimation solely based on the DC voltage level output of the power detector, thus offering a cost-effective and space-efficient solution that represents a significant advancement from traditional beam estimation methods.
Electrical engineering. Electronics. Nuclear engineering, Electricity and magnetism
It is known that an electric-magnetic duality transformation is a symmetry of the classical source-free Maxwell theory in generic spacetimes. This provides a conserved Noether charge, physically related to the polarization state of the electromagnetic field. We argue that this conservation law fails to hold at the quantum level in presence of a background classical gravitational field with non-trivial dynamics, as determined by the Chern-Pontryagin scalar. This is the spin 1 analog of the chiral anomaly for massless Dirac fermions.
Abstract Displacement susceptibility is a very important parameter to characterise the displacement polarisation of dielectrics. Two methods based on the time‐domain current and potential combined spectra are proposed to measure the displacement susceptibility. One is based on the time‐domain polarisation current and decay potential combined spectra, and the other is based on the time‐domain depolarisation current and recovery potential combined spectra. The principle of the proposed methods are verified by simulation. In addition, a measurement system for the two proposed methods is built and is used to measure the displacement susceptibility of transparent organic glass and opaque nonlinear field grading materials. The experimental results are compared with those of the present optical method and the frequency‐domain method. Simulation and experimental results show that the proposed methods for the measurement of displacement susceptibility are feasible and practical, which lays a foundation for the research on the polarisation characterisation of dielectrics.
In this paper, a CMOS wideband low-pass filter is proposed. In the wide band active filter design, the unit gain frequency (GBW) of OPAMP should be larger than GHz. The GBW of the proposed OPAMP is around 2.3 GHz. Additionally, the OPAMP with a complementary structure in signal and common mode feedback is proposed and has a wide operating voltage range at the input and output. The 1-dB gain compression point (P1dB) at the output is 4.9 dBm. A source follower is employed for driving 50 Ω output impedance without degrading the bandwidth and linearity of the filter. The power consumption is 27 mW from a 1-V supply voltage. The 3 dB bandwidth of the filter ranges from 330 MHz to 660 MHz with 3-bit cap tuning. This work is implemented in a 65-nm CMOS process, with a chip area of 0.18 mm2.
Electrical engineering. Electronics. Nuclear engineering, Electricity and magnetism
Steven H. Crouse, Stefani Kocevska, Sean Noble
et al.
On-line infrared absorbance spectroscopy enables rapid measurement of solution-phase molecular species. Many spectra-to-concentration models exist for spectral data, with some models able to handle overlapping spectral bands and nonlinearities. However, model accuracy is limited by the quality of training data used in model fitting. The process spectra of nuclear waste simulants at the Savannah River Site display incongruity between training and process spectra; the glycolate spectral signature in the training data does not match the glycolate signature in Savannah River National Laboratory process data. A novel blind source separation algorithm is proposed that preprocesses spectral data so that process spectra more closely resemble training spectra, thereby improving model quantification accuracy when unexpected sources of variation appear in process spectra. The novel blind source separation preprocessing algorithm is shown to improve nitrate quantification from an R2 of 0.934 to 0.988 and from 0.267 to 0.978 in two instances analyzing nuclear waste simulants from the Slurry Receipt Adjustment Tank and Slurry Mix Evaporator cycle at the Savannah River Site.
Aiming at the open-circuit detecting difficulty of the rotating diode of polyphase brushless exciter, the 39-phase-11-pole brushless exciter is taken as the example in this paper, the armature current characteristics of the brushless exciter during normal operation and single-tube open-circuit fault are analyzed. Firstly, the change law of armature magnetic field in two states is analyzed, a magnetic field detection coil is proposed to be installed on any pole of the stator in the exciter according to the structural characteristics of the exciter and electromagnetic coupling relationship. Then, combining with the harmonic characteristics of the spatial magnetic field of the brushless exciter, the flux expression of the detection coil is derived, and the induced voltage of the detection coil could be obtained. Specifically, it is found that an open diode fault causes a change in the amplitude of a specific frequency harmonic in the induced voltage. Finally, the finite element simulation proves that the detection coil method can effectively identify the rotating diode open circuit fault without affecting the normal operation of the brushless exciter.
Electricity, Production of electric energy or power. Powerplants. Central stations
Mareike Hummert, Paul Leenders, Alexander Mellmann
et al.
The application of the non-thermal atmospheric pressure plasma technology is a promising tool for microbial inactivation. During the activation process, many reactive substances and radicals arise associated with physicochemical changes in the fluid and massive pH drop. In this study, we analyzed and optimized plasma activation settings and conditions of water and liquids to obtain inactivation of the waterborne microorganism <i>Pseudomonas aeruginosa</i> in a liquid environment. The minimal electrical output was 60 Watt with 20 min activation time followed by 30 min contact time with 10<sup>8</sup> cells/mL. Using higher electrical power (>90 W) with a Lab Unit generating plasma-activated water, a shorter activation time (<10 min) was sufficient for bacterial inactivation. The organic and inorganic composition of the activated liquid with different mineral salt concentrations is of utmost importance for the yield of reactive species during the plasma activation process and consequently for the antimicrobial effect. Plasma-activated fluids with high organic and inorganic contents demonstrated lower inactivation efficiencies than low loaded fluids; yet antimicrobial efficacy could be achieved by increasing the electrical power and activation time. For sufficient inactivation of bacterial suspensions, at least half a volume unit of plasma-activated water had to be added after appropriately optimized activation. Further dilutions reduced the antimicrobial effect. PAW lost activity after being left standing for a prolonged time after activation, so for maximizing the antimicrobial effect a direct use after activation is recommendable. Bacterial inactivation was shown by the absence of colony forming units on culture media and, at the molecular level, damage to the membrane and inactivation of enzymes were observed. Plasma-activated fluids demonstrated a high potential in applications as microbiological disinfectant in liquids.
Vinod Kumar Gandi, Rishi Verma, Manoj Warrier
et al.
Sparkgap are most widely used closing switches in various high-voltage pulsed power systems and its reliable operation at desired voltage level is very essential. Conventionally by adjusting the filling gas pressure inside sparkgap switch, breakdown voltage level is altered but switching characteristics such as stability in hold-off voltage at various pressures, breakdown delay, plasma channel formation, and erosion rate are mainly dictated by adopted electrode profile and its dimensions, inter-electrode gap length and polarity. In this paper, experimental results obtained on breakdown characteristics of four different electrode geometries—Plane Parallel, Hemi-spherical, Bruce, and Rogowski and also a generalized criterion for fixing major dimensions of electrode and inter-gap length to ensure uniform electric field in the inter-electrode region are reported. All electrodes are of brass material and have common radius and thickness of 25 mm and 18 mm, respectively (surface finish <1 µm). Experiments performed on various electrode profiles in gap lengths of 2 mm to 5 mm range with pure nitrogen (N<sub>2</sub>) gas pressurization up to 50 psi reveal that among all profiles, Rogowski performs most reliably having stable hold-off voltage in wide operating range. Hold-off voltage magnitude and breakdown delay was commonly obtained higher for negative polarity in all trials. A comprehensive overview of experimental investigation reported herein compares suitability of various electrode profiles and polarity for reliable switching.
Overhead line tree barriers may cause line tripping faults and are a major hidden danger to line operation. It is a safe and effective way to remove the tree barriers under the transmission lines by high energy laser. By taking six types of typical trees as the research objects, finite element models are established to analyze the temperature distribution characteristics and burning efficiency of these trees under point and line laser cauterization, and point and line cauterization experiments are conducted respectively. The results show that the temperature of the tree surface decreases sharply from the the laser spot center to the spot edge, and the thermal effect is only obvious in the center of the burning area, and the temperature rising rate at the spot center slows down with the heating time. Within the same time period, compared to other five tree types, Paulownia has the highest temperature, reaching 1259.20 °C at maximum in 15 s. When the output power of laser is the same, the point laser and line laser have an average burning speed of 0.37 mm/s and 5.45 mm/s, respectively. The experimental results show that the line laser is 6.53-8.45 times faster than the point laser in average burning speed, which indicates that the line laser has a significantly higher burning speed than that of point laser. The research results can provide an important basis for application of line laser in clearing tree barriers.
Electricity, Production of electric energy or power. Powerplants. Central stations
We report the first investigation of the electrical and magnetic properties of the triangular-lattice compound Zr$_2$NiP$_2$ (space group $P$6$_3$/$mmc$). The temperature evolution of electrical resistivity follows the Bloch-Grüneisen-Mott law, and exhibits a typically metallic behavior. No transition is visible by both electrical and magnetic property measurements, and nearly no magnetization is detected ($M_0$ $<$ 0.002$μ_\mathrm{B}$/Ni) down to 1.8 K up to 7 T. The metallic and nonmagnetic characters are well understood by the first-principles calculations for Zr$_2$NiP$_2$.
Power data trading is an important way that data can play valuable role. However, there exists considerable problems in the present data trading, such as centralized trading trust, unclear trading rules and difficult transaction supervision. This paper proposed power trading scheme based on blockchain. Firstly, upon the analysis of the characteristics of power data and the problems encountered in power data trading, the applicability of block chain to power data trading scenarios is expounded. Then, the basic characteristics and classification of block chain technology are described. Next, the design details for intelligent contract are put forward to ensure the secure and automatic execution of power data transaction. Finally, in combination with consensus mechanism, transaction account and other factors, the blockchain-based power data transaction is proposed including its basic framework and especially the analysis of key supporting technologies to ensure the operation security and smoothness of power data trading.
Electricity, Production of electric energy or power. Powerplants. Central stations
The structure of delafloxacin meglumine was analyzed by infrared absorption (IR), ultraviolet absorption (UV), nuclear magnetic resonance (1H NMR, 13C NMR, DEPT, 1H-1H COSY, 1H-13C HSQC and 1H-13C HMBC) spectroscopy, mass spectrometry and elemental analysis. The characteristic absorption peaks in the IR spectra were discussed. The 1H and 13C NMR signals of delafloxacin meglumine were assigned, and the two-dimensional signals were used to elucidate its structure. The crystal structure of delafloxacin meglumine was studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD).
In this paper, a novel Fabry-Perot cavity (FPC) antenna with a perfect electric conductor (PEC) wall is proposed to design a structurally compact and robust high-gain antenna. Generally, the FPC antenna comprising a PEC ground and a partially reflective dielectric surface (PRDS) is required to have a half-wavelength height to satisfy the resonance condition. If a perfect magnetic conductor (PMC) is substituted for the PEC ground, the height of the FPC antenna can be reduced to a quarter wavelength. The PRDS of the proposed FPC antenna is located on the PEC ground to obtain the effect of a PMC. Moreover, PEC walls are employed to block leakage by a guided mode inside the PRDS. As a result, the proposed FPC antenna can be designed as a compact high-gain antenna although it is composed of PEC ground and PRDS. To verify its feasibility, we simulated and measured the performance of the proposed antenna regarding the reflection coefficient, peak gain, and far-field radiation pattern. Finally, the height of the proposed antenna was reduced by approximately 50% compared with the conventional antenna, while the peak gain is more than equal to that of the conventional antenna.
Electrical engineering. Electronics. Nuclear engineering, Electricity and magnetism
This paper established a fully renewable energy system which takes solar energy, wind energy and biomass energy as primary energy and meets the demand of electricity, heat and cooling loads. Considering the uncertainty of both energy source and load, a day-ahead economic dispatch model based on two-stage robust optimization was built and solved by column constraint generation (C & CG) algorithm. The simulation results show that renewable energy can be fully consumed by giving full play to its multi energy complementary characteristics. At the same time, the conservatism of robust optimization can be effectively improved by adjusting the uncertainty adjustment parameters, so as to improve the operation economy of the energy system and ensure safe and stable operation.
Electricity, Production of electric energy or power. Powerplants. Central stations