High Voltage Electric Research Articles

Factors Associated with Occurrence of Amputation in Electrical Burns

Background: Electrical burns can cause damage to blood vessels in the burning extremities . This damage can lead to amputation that significantly impacts both physically and psychologically that affects the quality of life. This study aimed to determine the incidence and factors associated with the occurrence of amputation in electrical burns. Method: A retrospective cohort study was done to patients with electrical burns that came to RSHS from 2011 to 2013. Mulativariate analysis, logistic regression, was performed on the factors associated with the occurrence of amputation in electrical burns. Result: Most of the electrical burns were suffered by men (93.5%) at reproductive age (mean 34.1 years; range 10-60 years of age). The incidence of amputation in electrical burns is 54.8% from 31 patients. There is a significant relationship between the causes of high-voltage electrical burns> 1000V with the occurrence of amputation (p = 0.008; Relative risk ratio 8,125 ; 95% CI= 1,62-40,752) and there is a significant relationship between the presence of third degree of burns with amputation (p = 0,011; Relative risk ratio 16; 95 % CI=1,643-155,76). There is no significant relationship between the extent of burns and lactate levels with the amputation on electrical burns. Conclusion: Amputation in electrical burns have a fairly high incidence. High electrical voltage> 1000V and presence of third degree of burns are associated with the occurrence of amputation.

Hybrid organic - inorganic filter system for cadmium ions adsorption from aqueous solutions

The study reflects on the problem of heavy metals, namely cadmium, polluting the natural environment. The goal was to select the most efficient adsorber enabling ion exchange between calcium and cadmium in an aqueous environment and subsequently design a material hybrid organic-inorganic, particle-fiber system that adsorbs cadmium from aqueous environments and will be easily included in the technological process. The novelty of this study lies in the use of waste food material – eggshells as a source of biogenic nanoparticles. These are applied to a nanofibrous structure made of polyvinyl butyral in amounts of 8 to 10 %wt by weight by the AC electrospinning. (The experiment was performed with these boundary conditions: temperature was 23°C, and humidity was 42%. The high-electrical voltage amplifier generated a sinusoidal waveform with a frequency of 50 Hz and an amplitude of 32 kV) and were used for ion exchange. In ion exchange, cadmium ions are exchanged with calcium ions based on the principle of chemical similarity of the two elements expressed by the z/r ratio (charge/ radius ratio), the z/r ratio is 2.02 for calcium ions Ca2+ and 2.06 for cadmium Cd2. Separateted nanoparticles of calcium carbonate obtained by burning eggshells (727°C) with dimensions from 100 to 200 nm and a specific surface area of 3.9 m2/g showed the highest adsorption capacity of 99.8%, synthetic calcium carbonate at 71.8%, and ground eggshells the lowest at 25.0%. Designed and laboratory-tested filter system of nanoparticles - nanofibers captures 95.6% and 96.8% of cadmium ions from an aqueous solution within 10 minutes and 90 minutes, respectively, at a concentration of cadmium ions of 10 mg/l, and at several nanoparticles of 0.3 g. The ion exchange is carried out only on the filter surface, and after a specific time, the calcium carbonate nanoparticles are released from the filter probably due to absence of chemical bond between nanoparticles and nanostructures or the low density of the nanofibrous structure. SEM, EDX, FTIR, BET and TGA analysis were used for material evaluation. The adsorption capacity of used nanoparticles and filter adsorbers was evaluated according to residual amounts of cadmium ions in aqueous solutions using ICP-IOS.

Overvoltage on the High and Low Side Electrical Network Voltage 35 kV When Appearing and Disconnecting Short Circuits of Various Forms at Its High Voltage Part

Overvoltage on the High and Low Side Electrical Network Voltage 35 kV When Appearing and Disconnecting Short Circuits of Various Forms at Its High Voltage Part

Investigation of process parameters of electrohydrodynamic jetting for 3D printed PCL fibrous scaffolds with complex geometries

Tissue engineering is a promising technology in the field of regenerative medicine with its potential to create tissues de novo. Though there has been a good progress in this field so far, there still exists the challenge of providing a 3D micro-architecture to the artificial tissue construct, to mimic the native cell or tissue environment. Both 3D printing and 3D bioprinting are looked upon as an excellent solution due to their capabilities of mimicking the native tissue architecture layer-by-layer with high precision and appreciable resolution. Electrohydrodynamic jetting (E-jetting) is one type of 3D printing, in which, a high electric voltage is applied between the extruding nozzle and the substrate in order to print highly controlled fibres. In this study, an E-jetting system was developed in-house for the purpose of 3D printing of fibrous scaffolds. The effect of various E-jetting parameters, namely the supply voltage, solution concentration, nozzle-to-substrate distance, stage (printing) speed and solution dispensing feed rate on the diameter of printed fibres were studied at the first stage. Optimized parameters were then used to print Polycaprolactone (PCL) scaffolds of highly complex geometries, i.e., semi-lunar and spiral geometries, with the aim of demonstrating the flexibility and capability of the system to fabricate complex geometry scaffolds and biomimic the complex 3D micro-architecture of native tissue environment. The spiral geometry is expected to result in better cell migration during cell culture and tissue maturation.

Advanced and Potential Methods for Extraction of Bioactive Compounds from Avocado Peel—A Review

Extraction techniques are continuously developed by the scientific community. Meanwhile, avocado peel is a by-product of avocado processing and a source of bioactive compounds. The purpose of this review was to summarize the use of advanced techniques for extracting bioactive compounds from avocado peel to help understand which techniques have and have not been applied to avocado peel. Three primary databases were used to collect the information, including Google Scholar, Scopus, and Web of Science, by using the keywords “avocado”, “peel”, and “extraction”. Additional keywords related to the extraction technique were also used, including “Microwave-Assisted Extraction”, “Ultrasound-Assisted Extraction”, “Enzyme-Assisted Extraction”, “Pressurized Liquid Extraction”, “Supercritical Fluid Extraction”, “Natural Deep Eutectic Solvents”, “Three-phase partitioning (TPP)”, “Pulsed-Electric Field”, “High Voltage Electric Discharge Plasma”, “Centrifugal Partition Extraction”, and “Surfactant-Mediated Extraction”. The results show that microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, TPP, and natural deep eutectic solvent extraction have been used to retrieve bioactive compounds from avocado peel. Other techniques have not yet been applied for the extraction of bioactive compounds from avocado peel. This article is the first review discussing the advanced extraction technique for retrieving bioactive compounds from avocado peel. This article creates a paradigm for future studies.

Research on the Effects of an Electrode Drill Bit during the Rock Drilling Process by High-Voltage Electric Pulse

Summary High-voltage electric pulse rock-breaking (HVEPB) has proved to be a novel and inexpensive method of breaking rock regardless of rock composition, but the design of the electrode drill bit lacks a theoretical basis. In this paper, we first establish a plasma channel model for electric breakdown and a numerical rock-breaking model for HVEPB, which can simulate the rock electrical breakdown plasma channel and the effect of different electrode drill bits on HVEPB. Second, we analyze the effects of different electrode arrangement structures and high-voltage electrode angles on plasma channels and the effects of internal cracks and rock-breaking processes through numerical simulation. Finally, we describe HVEPB experiments conducted using electrode drill bits with different electrode arrangement structures and high-voltage electrode angles, and with the boreholes reconstructed in three dimensions to analyze the effects of different electrode arrangement structures and high-voltage electrode angles on HVEPB drilling. The results show that the effects of the electrode drill bits on HVEPB are reflected mainly in the difference between the plasma channel and shock wave. Different electrode arrangement structures and high-voltage electrode angles result in different electric fields and energy utilization efficiencies within the rock, resulting in different shock waves and differences in the depth, shapes, and penetration of the plasma channels. The simulations and experimental studies in this paper can guide and optimize the design of the discharge tool to upgrade the drilling efficiency of HVEPB.

Skin Care Experience of a Case of Multiple Organ Failure Caused by High-Voltage Electrical Injury

Background: High-voltage electrical burns are caused by the direct transmission of electric current through the body and the conversion of electric energy into heat energy, which directly heats the tissues and leads to organ function damage. Especially after high-voltage electric burns (more than 1000W), it can not only cause coagulation necrosis of the skin and even carbonization, but also cause serious deep tissue damage .The degree of tissue damage depends on the type of current, the magnitude of current, the frequency, the voltage, the resistance of the tissue, the skin humidity, the duration, the contact area, and other factors. Low voltage and low frequency electric shock mainly affect the heart and respiration, which can lead to insignificant soft tissue damage. High voltage electric shock mainly causes serious soft tissue damage, which can be accompanied by changes in the circulatory system and respiratory system.[1] Subject and Method: We collected the data of a case of multiple organ failure caused by high-voltage electricity that was successfully treated in July 2023.In the course of this patient's successful treatment, The main nursing measures were analyzed: The intake and output volume were actively controlled. Albumin supplementation, Debridement and dressing change were performed daily, Covered with nano-silver ion dressing, Try to ensure a sterile environment during operation, Maintain ambient temperature and humidity. Results: Twenty days later,the skin damage caused by electric burns was reduced from 30% to 1%. Conclusion: These are very important links: The intake and output volume were actively controlled, The balance of intake and output was maintained for 24 hours, and lactic acid was less than 2mmol/L. Albumin supplementation Controlled above 30g/L, Debridement and dressing change were performed daily, Covered with nano-silver ion dressing, Try to ensure a sterile environment during operation, Maintain ambient temperature 28~30℃ and humidity 40%~50%.

Lung Parenchymal Damage Due to High Voltage Electric Shock

In electric shocks, lung tissue is a poor conductor and has low resistance. Therefore, they are not very sensitive to the development of tissue damage due to electric current. In this study, we wanted to present a rare case of lung parenchymal burn as a result of electric shock. A 21-year-old male patient was brought to the emergency department by ambulance after being electrocuted with a current of 15,000 volts after contact with a high voltage line while working with a construction machine. The general condition of the patient was good and vital signs were stable. However, his pulse oxygen value was 74 and his breathing was slightly tachypneic. There were no lesions in the chest and abdomen due to electrical burns. Radiologic imaging showed bilateral diffuse tissue damage in the lung tissue. The patient was referred to a tertiary care institution with an intensive care burn unit. In traumas caused by high-voltage electric shock, burns on the body surface may be insufficient to determine the severity of the trauma. A multidisciplinary approach must be provided to these patients.

Dry water: Toward an ideal extinguishant for lithium-ion battery fire

Developing an environment-friendly, high-cooling, non-conductive, and low-cost extinguishant has been the focus on fighting lithium-ion battery (LIB) fires. In this work, dry water (DW), a powdered material containing copious amounts of liquid water, was first studied as an extinguishant for LIB fires. Benefiting from the core-shell structure and dispersibility properties as a dry powder, DW shows a high electric breakdown voltage, which enables it to overcome the conductivity drawback of liquid water. Moreover, although the endothermic enthalpies of DWs are only about 82.4–95.7 % of liquid water, their water evaporation rates are faster than liquid water, which brings DWs a better cooling effect than liquid water in suppressing thermal runaway propagation. Thus, DW combines the advantages of both liquid water (high cooling ability) and dry powder (low conductivity), and presents a great application potential to control LIB fires.

Research on optimization of electrical parameters of EDM based on a neural network algorithm

An electrical Discharge Machine (EDM) is an effective spark machine that passes the sparks to get the desired shape by performing metal fabrication. In the EDM process, materials are removed between the two electrodes by transferring the workpiece’s high electric voltage and dielectric liquid. The voltage between the two electrodes is gradually increased to break down the dielectrics and remove the materials from the surface. EDM utilizes several parameters to regularize the material removal rate during this process. EDM changes its parameter for every experiment to minimize the Average Tool Wear Rate (ATWR). The existing techniques utilize a neural model to optimize the EDM parameter. However, the traditional approaches fail to perform the fine-tuning process that affects the Material Removal Rate (MRR) and ATWR. Therefore, meta-heuristics optimization techniques are incorporated with the neural model to enhance the EDM parameter optimization process. In this work, the EDM experimental data have been collected and processed by the learning process to create the training pattern. Then, the test data is investigated using the Backpropagation Neural Model (BPM) to propagate the neural parameters. The BPM model is integrated with the Butterfly Optimization Algorithm (BOA) to select the search space’s global parameters. This analysis clearly shows an 8.93% maximum prediction rate, 0.023 minimum prediction rate and 2.83% mean prediction rate while investigating the different testing patterns compared to other methods.

Investigating the Effect of High Voltage Electric Field on the Pesticide Residue in Tomatoes Using the Thermal Imaging Technique

Investigating the Effect of High Voltage Electric Field on the Pesticide Residue in Tomatoes Using the Thermal Imaging Technique

Oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by high-voltage electrical burn.

The pathogenesis of post-traumatic stress disorder (PTSD) triggered by high-voltage electrical burn (HVEB) remains unclear and the oxidative stress plays a role in this process. The purpose of this study is to investigate the underlying mechanism of oxidative stress mediates hippocampal neuronal apoptosis in rats with PTSD triggered by HVEB. The PTSD rat model was developed by stimulating with high voltage electricity and screened using behavioral performance including Morris water maze (MWM), elevated plus-maze (EPM) and open-field test (OFT). The reactive oxygen species (ROS) generation was measured by DHE fluorescence staining or flow cytometry. Western blotting assay was used to detect the proteins of p-JNK, JNK, P53, PUMA, Bcl-2 and Bax in hippocampal tissue or HT22 cells treated with electrical stimulation. The serum MDA and 8-OHdG levels were increased (P < 0.001), while the activities of SOD and CAT were decreased (P < 0.001) significantly in patients with HVEB. Behavioral test results showed that high-voltage electric stimulation induced the PTSD-like symptoms and the ROS-JNK-P53 pathway was involved in the neuronal apoptosis in rats with PTSD induced by HVEB. In vitro experiments further confirmed the electrical stimulation induced neuronal apoptosis through ROS/JNK/P53 signaling pathway and the antioxidant NAC could rescued the ROS generation, activation of JNK/P53 proteins and improved the cell apoptosis rate in HT22 cells. Finally, the JNK inhibitor SP600125 could significantly inhibited the percentage of HT22 cell apoptosis induced by electrical stimulation (P < 0.001). These results indicated that oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by HVEB.

Stability of Glass Ceramic Sealants in Atmospheres with Increased Water Contents

For Solid oxide fuel cells (SOFC), operating at temperatures above 800 °C, glass ceramic sealants are state of the art. The properties of the glass ceramics are adapted to the metallic and ceramic join partners, operation conditions, as also to the atmospheres: fuel gas and air. In SOFCs, glass ceramic sealants offer reliable, long term stable operation over several 10,000 hours of service. The demand to operate solid oxide cells (SOC) in fuel cell- as also in electrolysis cell mode increases the demands of the stability of the sealants against atmospheres. In the electrolysis mode, the SOC-stacks were impinged by gas with high water contents to produce H2. Water contents of up to 95 % and temperatures above 800 °C are hard conditions for all applied materials of SOC stacks. In addition, glass ceramic sealants have to electrical insulator under applied electric voltage. In the electrolysis mode, the applied voltage is even higher than in fuel cell mode. In conclusion, the electrolysis mode is much harsher as fuel cell mode and glass ceramic sealants have to be adapted to this. Glasses in the system BaO-CaO-Al2O3-B2O3-SiO2 with La2O3-additions have the potential to form glass ceramics with extraordinary high coefficient of thermal expansion (CTE)values, which are suitable for use as sealants compatible with Crofer 22 APU interconnect. Their characteristics have been generally described in various studies and are also in focus of our own work and have proven their suitability for use under SOFC operating conditions. However, achieving such high CTE values is especially challenging when these glasses must be designed for use in stacks operating with electrolyte supported cells because sealing and operating temperature are usually higher than in other stack designs. Their behavior under simulated electrolysis conditions together with a direct correlation of test by using these glasses as sealants in real stack designed to operate with electrolyte supported cells has not been investigated yet and presents the scope of this study.For this study, a series of glasses has been prepared as glass powders and characterized in terms of relevant thermophysical properties such as softening behavior, thermal expansion and formation of crystalline phases. La2O3-free sealing glasses established as standards for use in commercial stacks served as references and results of both groups of sealing glasses have been compared. The new La2O3-containing glasses showed CTE-values up 10.8 ppm K-1 at a glass transition temperature ranging between 640°C and 650°C for a partially crystallized microstructure. The softening and crystallization characteristics analyzed by hot stage microscopy and DSC/TGA allow sealing processes of stacks components in the temperature range between 900°C and 950°C. Helium-leakage rates of sealed sandwich type samples made of Crofer 22 APU showed values below 10-8 mbar l-1 s-1. From suitable glasses sandwich type sample sealings made of two Crofer 22 APU coupons have been prepared and exposed to a dual atmosphere in a special test rig under simulated electrolysis conditions at 850 °C with different electrical voltages applied across the sealants and a water content of 50 % in the steam atmosphere. In this out-of-stack environment, the resistance of the glass sealants can be recorded while being treated with high water atmosphere and electric voltage of up to 5 V at 850 °C. The development of resistance over 300 hours of aging show which glass composition fit to the conditions and which exhibit high degradation rates. Afterwards cross sections have been prepared and analyzed by SEM. Effects observed in the interfacial regions glass-Crofer 22 APU and glass-atmosphere have been correlated with the electrical measurements. A 30 layers stack was tested under typical SOEC conditions for approx. 3200 hours. Four different glass types were used and compared in terms of their degradation rate and the ASR value. The selection of the glasses was made according to their thermal expansion and softening behavior as well as their insulating properties.

Hierarchical Capillarity-Assisted Liquid Invasion in Multilayered Paper Channels for Nanoelectrokinetic Preconcentration.

A nanoelectrokinetic phenomenon called ion concentration polarization (ICP) has been recently applied to microfluidic paper-based devices for the high fold preconcentration of low-abundant analytes. The inherent microstructural characteristics of cellulose papers can sufficiently stabilize the chaotic electroconvection of ICP, which is a significant annoyance for typical engineered microfluidic channels. However, a high electrical voltage to induce ICP in a paper-fluidic channel can increase unavoidable electrophoretic forces over drag forces so that the preconcentrated plug is rapidly receded with severe dispersion. In order to enhance the hydraulic drag force that helps the preconcentration of analytes, here we introduce a multilayered paper structure into paper-fluidic channel. We theoretically and experimentally demonstrate that a hierarchical capillary structure in a multilayered paper-fluidic channel can effectively increase the hydraulic drag force. For the practical utility in the field of diagnostics, the mechanism is verified by a simple example of the immunoassay using biotin-streptavidin complexation.

Nature of the abnormally high photocurrent relaxation time in the a-Ga2O3-based Schottky diodes

Ga2O3 is an ultra-wideband material with excellent optical characteristics. It is a promising material for power applications and optoelectronics because of its high electrical breakdown voltage and radiation hardness. It is optically transparent for visible light and UVA but UVC-sensitive. One of the main disadvantages of this material is the anomalous slow photoeffect: photoconductivity rise and decay characteristic times can be more than hundreds of seconds long. This "slow" photoconductivity effect severely limits the utilisation of the Ga2O3-based devices. The aim of this work is the investigation of the nature of this effect. The results of the photoinduced current rise and decay under 530 nm and 259 nm LED are measured in the HVPE-grown α-Ga2O3-based Schottky diode. Upon UV-illumination the photocurrent rise consists of three parallel processes: fast signal growth, slow growth and very slow decay with characteristic times near 70 ms, 40 s and 300 s respectively. Subsequent 530 nm LED illumination resulted in photoinduced current rise consisting of two mechanisms with characterisatic times 130 ms and 40 s on which a very slow decrease of the photocurrent amplitude with characteristic time of 1500 s was superimposed. 530 nm illumination stimulates this process. Protoinduced current relaxation analysis shows the presence of the deep levels with energies (EC - 0.17 eV). It is suggested that extremely slow relaxations can be associated with potential fluctuations near the Schottky barrier.

Investigation on Large-Scale Tests of Rock Fracturing by High-Voltage Electric Pulse with Voltage as a Variable

In this paper, we use an independently developed high-voltage electrical pulse (HVEP) system to implement fracturing of solid rocks. The discharge capacitance was 150 μF, and the voltage was increased from 8 to 14 kV to increase the discharge energy. The rock appears cracked at 14 kV and 150 μF. The parameters current, strain, and vibration are utilized to investigate the rock-breaking pattern of HVEP. An increase in voltage can generate a heightened destructive effect. The enhanced effects are reflected in the peaks of current, strain, and vibration. Cracks result in an acceleration of the rate of decay of the vibration curve. Also, the rate of variation of the peak strain raises. According to the spectrum analysis, HVEPs primarily generate low-frequency energy to crack rocks in the 0 to 2000 Hz range.

Designing Robust Networks of Coupled Phase Oscillators With Applications to the High Voltage Electric Grid

We propose a mathematical framework for designing robust networks of coupled phase-oscillators by leveraging a vulnerability measure proposed by Tyloo et al. that quantifies the impact of a small perturbation at an individual phase-oscillator's natural frequency to the system's global synchronized frequencies. Given a complex network topology with specific governing dynamics, the proposed framework finds an optimal allocation of edge weights that minimizes such vulnerability measure(s) at the node(s) for which we expect perturbations to occur by solving a tractable semi-definite programming problem. We specify the mathematical model to high voltage electric grids where each node corresponds to a voltage phase angle associated with a bus and edges correspond to transmission lines. Edge weights are determined by the susceptance values along the transmission lines. In this application, frequency synchronization is increasingly challenged by the integration of renewable energy, yet is imperative to the grid's health and functionality. Our framework helps to alleviate this challenge by optimizing the placement of renewable generation and the susceptance values along the transmission lines.

Research on Intelligent Verification System of High Voltage Electric Energy Metering Device Based on Power Cloud

To address the issues of low efficiency, poor security, insufficient compatibility, and difficulties in traceability associated with high-voltage electric energy metering (HVEEM) device verification methods, this paper proposes a design scheme for a remote verification system (RVS) of such devices based on a power cloud platform (PCP). The system adopts the concept of “high-precision local sampling + remote cloud verification” and develops a local acquisition device with compatibility and high precision to achieve fast acquisition of local electrical parameters. The IEC 61850 communication modeling is utilized to establish unified communication standards between the local device and the PCP. The PCP provides two verification methods: physical error verification based on a multi-channel standard and digital verification based on an improved Backpropagation (BP) neural network simulation model. Leveraging the advantages of power cloud technology, the system enables functions such as electrical energy calculation, remote intelligent error verification, cloud storage, condition monitoring, and early warning. Through testing and application, it has been demonstrated that the system achieves an integration accuracy level better than 0.02. It also exhibits good security, compatibility, and traceability of measurement values while attaining a high level of informatization and intelligence. Particularly, the system shows promising prospects for the remote and efficient verification of large-scale and multi-type high-voltage metering devices.

High Voltage Electric Pulse Drilling: A Study of Variables through Simulation and Experimental Tests

With the deepening of drilling depth, the difficulty of drilling engineering increases gradually due to the complex geological conditions. The traditional mechanical drilling method shows the problems of high energy consumption, low efficiency, long cycle and high cost. Because of the characteristics of rock, the high abrasiveness of rock causes great wear to the bit, which becomes an important factor affecting the drilling rate. High voltage electric pulse (Abbreviated as HVEP later in this paper) drilling technology is a new technology developed in the past several decades. The technology uses plasma channel, water jet or shock wave generated by high voltage electric pulse discharge to break rock. It has the characteristics of environmental protection, directional breaking, easy control of rock breaking process and fast speed in the face of complex hard rock. In this paper, the mechanism and technology of rock breaking by high voltage electric pulse method in deep drilling are studied, and the functional test is carried out.

Causes of the appearance of current waves in high voltage electric arc furnaces, and methods of their reduction

This article presents a method of generation and reduction of current waves in high-voltage electric arc furnaces in industrial and mining enterprises, in contrast to existing methods. The developed method is currently relevant for the solution of problems related to the generation of current waves during the operation of high-voltage electrics are furnaces with a power of 3 MWt used in the melting and pouring of metals of different densities at the Navoi mechanical engineering plant. The main goal of implementing the developed method is to reduce the electric energy consumption of high-voltage electrics arc furnaces and to increase the efficiency of electric energy consumption of the furnace.