As an important part of power system, transformer plays irreplaceable role in the process transmission. Diagnosis transformer's failure is significance to maintain its safe and stable operation. Frequency response analysis (FRA) has been widely accepted as effective tool for winding deformation fault diagnosis, which one common failures transformers. However, there no standard reliable code FRA interpretation so far. In this paper, support vector machine (SVM) combined with diagnose faults....

Frequency response analysis (FRA) has recently been developed as a widely accepted tool for power transformer winding mechanical deformation diagnosis, and proven to be effective powerful in many cases. However, there still exist problems regarding the application of FRA. FRA is comparative method which measured signature should compared with its fingerprint. Small differences signatures certain frequency bands might produced by external disturbance, hinders fault diagnosis. Additionally,...

MicroRNA (miRNA) detection is a critical aspect of disease diagnosis, and recent studies indicate that miRNA-622 could be potential target for lung cancer. Herein, Cu single atoms were anchored on graphitic carbon nitride (Cu SAs@CN) as coreaction accelerator applied in luminol-H

A bipolar pulse has been proved to be more advanced in the treatment of tumor because elimination muscle contractions and effect for ablating nonuniform tissue. In this paper, a new type modular pulsed-power generator based on Marx with double power charging is proposed. The concept two series capacitors parallel by sources, respectively, then connecting through solid-state switches different control strategies. Utilizing number fast switches, can connected polarities, so that positive or...

The necessity of the multi-layered aluminium (Al) tabs to copper (Cu) busbars for electric vehicle (EV) batteries is increasing. Electromagnetic pulse welding (EMPW) applicable conductive dissimilar/similar materials. In this work, three Al sheets and a single Cu sheet are joined by EMPW technology. layer-wise tensile lap shear properties Al–Cu joint evaluated. interfacial microstructures parallel perpendicular direction studied scanning electron microscopy (SEM) transmission (TEM)...

Frequency response analysis (FRA) has been widely accepted as a diagnostic tool for power transformer winding deformation faults. Typically, both amplitude-frequency and phase-frequency signatures are obtained by an FRA analyzer. However, most existing analyzers use only the information on signature, while is neglected. It also found that in some cases, results do not comply with hard evidence. This paper introduces method based of binary images from to improve outcomes. The digital image...

Feature extraction and fusion are two critical issues for the task of multisource classification. In this article, we propose an enhanced network (EMFNet) to address them in end-to-end framework. Specifically, convolutional neural networks employed extract features from different sources. Each is mainly comprised three layers. For each layer, feature tuning modules designed enhance extracted one source by taking advantage other source. After getting sources, a weighted summation method used...

Based on multilayer dielectric model, for the spherical biological cell subjected to pulsed electric field (PEF), an equivalent circuit model is presented. Frequency-domain analysis shows that inner and outer membranes exhibit band-pass low-pass filter characteristics in response PEF, respectively. Therefore, different biomedical effects will be induced by with frequency spectrum. The method calculate transmembrane potentials time-varying PEF introduced, relationship between rectangular...

Interfacial shear strengths or static frictions between carbon nanotubes (CNT) in contact at different cross angles are studied by using atomic mechanics. It is shown that the axial interfacial parallel CNTs commensurate two orders of magnitude greater than those incommensurate. This strong chiral dependence not surprising and similar to friction graphite basal planes. In contrast, we find crossly contacted CNT pairs much less dependent upon chirality. The estimated values strengths, ranging...

High-voltage electric field pulses can make cell membrane electroporated irreversibly and eliminate malignant cells via necrosis. However, low-voltage is not efficient as that.This study determined the differential effects of high- on HeLa cells, when power was enhanced by increasing quantity pulses.Pulses fields with permanent frequency (1 Hz) pulse length (100 μs) were performed cells. Voltage sets (8 pulses/set) various during treatment. CCK-8 assay used to detect viability. The...

High-frequency nanosecond-pulsed electric fields were recently introduced for tumor or abnormal tissue ablation to solve some problems of conventional electroporation. However, it is necessary study the thermal effects high-field-intensity nanosecond pulses inside tissues. The multi-parametric analysis performed here based on a finite element model liver with that has been punctured by pair needle electrodes. pulse voltage used in this ranges from 1 4 kV, width 50 500 ns, and repetition...

The Marx circuit structure based on fast high-power semiconductor devices is the classical way of generating picosecond pulses. However, most reported studies suggest that as number stages in increases, output pulse amplitude tends to saturate. This has late made high-voltage picosecond-pulse generation a challenge. In this paper, internal resistance avalanche transistor decrease with increasing current flowing through transistor. A step-by-step wiring and debugging transistor-based...

Winding deformation is a common problem that takes place within operating power transformers due to various internal and external conditions. Due their progressive nature, winding deformations should be detected rectified as soon they emerge. Unfortunately, the only reliable technique detect such faults at this stage frequency response analysis which conducted offline. This has motivated researchers propose alternative techniques transformer incipient core in real time. One of promising...

This paper considers the electroporation characteristics of a cell under high-frequency nanosecond pulse bursts. A typical two-dimensional system, including an organelle membrane, was discretized into nodes using MATLAB, and mesh transport network method model established after bidirectional coupling properties electrical pore were assigned to within this model. The dynamic process in single-cell application 10 unipolar bursts at 1 Hz target system simulated analyzed. single burst multiple...

Electromagnetic pulse welding (EMPW) is an environmentally friendly and advanced manufacturing technology. Researches find the macro-morphology of EMPW joint sheets presents a multilayer ellipse. The experiments Al-Cu Al-Mg were carried out, both micro-morphology showed there collision zone, bonding zone affecting in joint, presenting elliptical morphology, which was independent material. welded seam zone. 3D multiphysics simulation results also that distribution plastic deformation Al...

Power transformers have important roles as voltage converters in substations, which directly affect the safe operation of power grids. Online monitoring winding deformation, is one most common transformer faults, crucial protecting from damage, particularly those induced by short-circuit current failures, and ensuring their operation. This study proposes an improved online method for deformations based on Lissajous graphical analysis current. A practical measurement system also presented...