Through Holes Research Articles

A low-profile electromechanical packaging system for soft-to-flexible bioelectronic interfaces.

Interfacing the human body with the next generation of electronics requires technological advancement in designing and producing bioelectronic circuits. These circuits must integrate electrical functionality while simultaneously addressing limitations in mechanical compliance and dynamics, biocompatibility, and consistent, scalable manufacturing. The combination of mechanically disparate materials ranging from elastomers to inorganic crystalline semiconductors calls for modular designs with reliable and scalable electromechanical connectors. Here, we report on a novel interconnection solution for soft-to-flexible bioelectronic interfaces using a patterned and machined flexible printed circuit board, which we term FlexComb, interfaced with soft transducing systems. Using a simple assembly process, arrays of protruding "fingers" bearing individual electrical terminals are laser-machined on a standard flexible printed circuit board to create a comb-like structure, namely, the FlexComb. A matching pattern is also machined in the soft system to host and interlock electromechanically the FlexComb connections via a soft electrically conducting composite. We examine the electrical and electromechanical properties of the interconnection and demonstrate the versatility and scalability of the method through various customized submillimetric designs. In a pilot in vivo study, we validate the stability and compatibility of the FlexComb technology in a subdural electrocorticography system implanted for 6 months on the auditory cortex of a minipig. The FlexComb provides a reliable and simple technique to bond and connect soft transducing systems with flexible or rigid electronic boards, which should find many implementations in soft robotics and wearable and implantable bioelectronics.

Research progresses on the effects of heavy metals on the circadian clock system.

Environmental pollution with heavy metals is widespread, thus increasing attention has been paid to their toxic effects. Recent studies have suggested that heavy metals may influence the expression of circadian clock genes. Almost all organs and tissues exhibit circadian rhythms. The normal circadian rhythm of an organism is maintained by the central and peripheral circadian clock. Thus, circadian rhythm disorders perturb normal physiological processes. Here, we review the effects of heavy metals, including manganese, copper, cadmium, and lead, on four core circadian clock genes, i.e.,ARNTL, CLOCK, PER, and CRY genes.

Effectiveness of Hydrilla verticillata as Bioaccumulator Against Soil Contamination in Flooded Rice Cultivation

Soil pollution can occur due to agricultural waste, one of which is the excessive use of pesticides. Contaminants that are often found are heavy metal of copper (Cu). Rice plants will absorb and store heavy metal elements in polluted soil and waters, and these heavy metals will undergo a process of bioaccumulation in plants that affect plant growth. Efforts to deal with heavy metal contaminants have been carried out. In its application, plants such as hydrilla plant (Hydrilla verticillata) can be used to reduce pollution in the environment. This study aims to determine the effectiveness of using hydrilla plants in reducing heavy metal pollutant copper in flooded rice cultivation. This research was conducted from May-November 2022 at the Agrotechnology Greenhouse, and for laboratory testing it was carried out at the CDAST Laboratory, University of Jember. This research was conducted using a completely randomized design consisting of one factor with four replications. Giving hydrilla did not significantly affect the morphology of rice plants but had a significant effect on the increasing levels of chlorophyll. The concentration of copper in rice plants decreased after treatment with hydrilla plants compared to negative controls without hydrilla plants. In this study, it can be concluded that the use of hydrilla was able to reduce the levels of copper metal present in rice plants and did not affect the growth of rice plants morphologically.
 
 Keywords: copper, hydrilla, paddy, soil contamination

Study on quality parameters of wine at opening and deterioration with time

Wine is an alcoholic beverage made from grapes containing alcohol ranging from 5-15% by volume. Wine consumption in the Nepalese market is gaining steady growth in recent years. In this study, parameters such as specific gravity, total acidity, pH, percentage of alcohol content, amount of total dissolved solid, presence of furfural, methyl alcohol and heavy metal were selected for analysis of red and white wine with time after the opening of the packet wine at the time interval of 15, 20 and 25 days respectively. An increase in acidity and specific gravity (0.9780-0.9992 g/mL) while decrease in alcohol content (9.54%-8.03% by volume), presence of heavy Iron and Copper found below 0.003 and absence of furfural and methyl alcohol were observed with time. Consumption of wine in controlled amounts could prevent heart disease and circulatory problem. However, excess wine consumption can inhibit new brain cell development and depressive disorders.

BurstDECONV: a signal deconvolution method to uncover mechanisms of transcriptional bursting in live cells.

Monitoring transcription in living cells gives access to the dynamics of this complex fundamental process. It reveals that transcription is discontinuous, whereby active periods (bursts) are separated by one or several types of inactive periods of distinct lifetimes. However, decoding temporal fluctuations arising from live imaging and inferring the distinct transcriptional steps eliciting them is a challenge. We present BurstDECONV, a novel statistical inference method that deconvolves signal traces into individual transcription initiation events. We use the distribution of waiting times between successive polymerase initiation events to identify mechanistic features of transcription such as the number of rate-limiting steps and their kinetics. Comparison of our method to alternative methods emphasizes its advantages in terms of precision and flexibility. Unique features such as the direct determination of the number of promoter states and the simultaneous analysis of several potential transcription models make BurstDECONV an ideal analytic framework for live cell transcription imaging experiments. Using simulated realistic data, we found that our method is robust with regards to noise or suboptimal experimental designs. To show its generality, we applied it to different biological contexts such as Drosophila embryos or human cells.

Hierarchical Automatic Multilayer Power Plane Generation With Genetic Optimization and Multilayer Perceptron

Abstract We present an automatic multilayer power plane generation method to accelerate the design of printed circuit boards (PCB). In PCB design, while automatic solvers have been developed to predict important indicators such as the IR-drop, power integrity, and signal integrity, the generation of the power plane itself still largely relies on laborious manual methods. Our automatic power plane generation approach is based on genetic optimization combined with a multilayer perceptron (MLP) and is able to automatically generate power planes across a diverse set of problems with varying levels of difficulty. Our method GOMLP consists of an outer loop genetic optimizer (GO) and an inner loop MLP that generate power planes automatically. The critical elements of our approach include contour detection, feature expansion, and a distance measure to enable island-minimizing complex power plane generation. We compare our approach to a baseline solution based on A*. The A* method consisting of a sequential island generation and merging process which can produce less than ideal solutions. Our experimental results show that on single layer power plane problems, our method outperforms A* in 71% of the problems with varying levels of board layout difficulty. We further describe H-GOMLP, which extends GOMLP to multilayer power plane problems using hierarchical clustering and net similarities based on the Hausdorff distance.

Additive manufacturing of IoT housings with integrated electronics

Additive manufacturing (AM) is an established fabrication method for diverse applications. Due to the versatile manufacturing possibilities, AM provides totally new approaches in designing objects. An emphasis in the field of research was set to the development of unique materials for AM. Among them, conductive filaments were examined for applications in printed electronics. The combination of new materials and the innovative design approach offered by AM generates a comprehensive field of applications. Promising applications can be found on the “Internet of Things (IoT)” sector. The development of connected products includes physical and electronic components. Traditionally, the fabrication process of these products is linear, thus, the design and the fabrication of the physical components is separated from the electronic part. To overcome this separation, an AM approach can be applied in the fabrication of IoT devices. This additive multi-material fabrication approach enables the fabrication of mechanical and electric components in one fabrication process. To prove this fabrication approach, antennas for IoT devices consisting of a supportive element and a antenna element for signal transmission were designed. The antennas were fabricated by material extrusion combining non-conductive and conductive filaments. Two different antennas (patch and arc antenna) were designed focusing on one specific frequencies range: 868 MHz (LoRa). To compare the AM antenna, reference antennas have been fabricated by etching. Antennas were characterized by simulation and measuring the return loss of the fabricated specimen. Finally, the transmission of a payload was tested in a real-world scenario. The tested antennas were able to transmit a payload, however, the return loss differed between the different designs and fabrication approaches. Nevertheless, the additive multi-material fabrication process enables an integrated production approach which led to functional devices. In this sense, electronics and physical components are merged into a truly smart product. Based on the findings, further applications of the hybrid approach will be investigated e.g., signal traces, passive electrical components to further strengthen the extensive application possibilities of additive manufacturing.Graphical abstract

Heavy Metal Mediated Progressive Degeneration and Its Noxious Effects on Brain Microenvironment.

Heavy metals, including lead (Pb), cadmium (Cd), arsenic (As), cobalt (Co), copper (Cu), manganese (Mn), zinc (Zn), and others, have a significant impact on the development and progression of neurodegenerative diseases in the human brain. This comprehensive review aims to consolidate the recent research on the harmful effects of different metals on specific brain cells such as neurons, microglia, astrocytes, and oligodendrocytes. Understanding the potential influence of these metals in neurodegeneration is crucial for effectively combating the ongoing advancement of these diseases. Metal-induced neurodegeneration involves molecular mechanisms such as apoptosis induction, dysregulation of metabolic and signaling pathways, metal imbalance, oxidative stress, loss of synaptic transmission, pathogenic peptide aggregation, and neuroinflammation. This review provides valuable insights by compiling the supportive evidence from recent research findings. Additionally, we briefly discuss the modes of action of natural neuroprotective compounds. While this comprehensive review aims to consolidate the recent research on the harmful effects of various metals on specific brain cells, it may not cover all studies and findings related to metal-induced neurodegeneration. Studies that are done using bioinformatics tools, microRNAs, long non-coding RNAs, emerging disease models, and studies based on the modes of exposure to toxic metals are a future prospect to be explored.

Influence of Water Ingress on Surface Discharges Occurring on the Silicone Gel Encapsulated Printed Circuit Boards Developed for Deep-Sea Applications

This paper discusses the influence of water ingress on the electrical discharges that arise on the surface of printed circuit boards that are developed for deep sea applications. The primary concern is the electrical discharges arising on the surface of the PCB bridging localized spots/areas between conductive traces, high voltage terminal, mounting hole options, and so on. The current literature focuses on electrical discharges arising on the surface of PCB at low-pressure environments emulating aircraft and space applications. Extending the same approach to deep-sea environments is not feasible since the pressure is very high and the temperatures are very low. In all, a meager attempt has been made to investigate the possible application of such gel-encapsulated PCBs in adverse high-pressure, salt/sea water, low-temperature, deep-sea environments. This experimental study focuses on studying the influence of deionized and sea water on electrical discharges arising on the surface, between conductive tracks of PCB. A group of PCBs with different gaps between the conductive tracks was produced and immersed in deionized and seawater for a specific duration at standard pressure. Afterward, the discharge characteristics were measured the using partial discharge (PD) test method and the respective phase-resolved PD pattern was studied and analyzed. Pertinent experiments revealed that the PD process and eventual failure manifests as a typical and substantial pattern. The apparent charge measured during the PD inception and near-by failure condition, influenced by deionized and seawater, reveals a regular trend. Naturally, a simple observation of the PD pattern might help to identify the intricacy and to initiate a preventive measure well before the complete system suffers a premature failure. Also, based on these results, making slight structural modifications on the PCB at crucial locations might help in retaining the dielectric integrity of the material.

Design of a Portable and Reliable Fluorimeter with High Sensitivity for Molecule Trace Analysis

There is a growing need for portable, highly sensitive measuring equipment to analyze samples in situ and in real time. For these reasons, it is becoming increasingly important to research new experimental equipment to carry out this work with advanced, robust and low-cost devices. In this framework, a flexible, portable and low-cost fluorimeter (under EUR 500), based on a C12880 MA MEMS micro-spectrometer with an Arduino compatible breakout board, has been developed for the trace analysis of biological substances. The proposed system can employ two selectable excitation sources for flexibility, one in the visible region at 405 nm (incorporated in the board) and an external LED at 365 nm in the UV region. This additional excitation source can be easily interchanged, varying the LED type for investigating any fluorophore compound of interest. The measurement process is micro-controlled, which allows the precise control of the spectrometer sensitivity by adjusting the integration time of each experiment separately. Data acquisition is easy, reliable and interfaced with a spreadsheet for fast spectra visualization and calculations. For testing the performance of the new device in fluorescence measurements, different fluorophore molecules which can be commonly found in biological samples, such as Fluorescein, Riboflavin, Quinine, Rhodamine b and Ru (II)-bipyridyl, have been employed. A high sensitivity and low quantitation limits (in the ppb range) have been found in all cases for the investigated chemicals. The portable device is also suitable for the study of other interesting phenomena, such as fluorescence quenching induced by chemical agents (such as halide anions or even auto-quenching). In this sense, an application for the quantification of chloride anions in aqueous solutions has been performed obtaining a LOD value of 18 ppm. The obtained results for all chemicals investigated with the proposed fluorimeter are always very similar in quantification figures, or even better than the data reported in literature, when using commercial laboratory equipment.

Phytoremediation Capacity of Water Hyacinth (Eichhornia crassipes) as a Nature-Based Solution for Contaminants and Physicochemical Characterization of Lake Water

Water hyacinth (Eichhornia crassipes) is a potential accumulator of water pollutants in aquatic ecosystems, and its presence in water systems can affect water quality. This study used different field measurements and laboratory tests of lake water to determine the impact of water hyacinth phytoremediation capacity. A total of eight sampling stations were used for the two lakes: Lake Koka and Lake Ziway, Ethiopia. Sampling stations were selected from sites infested with water hyacinth (low, medium, and high) and non-water hyacinth aquatic plants during wet or rainy and dry or non-rainy seasons to compare the effects of plants on water quality in the two lakes. All the sampled stations had various human interventions. The water samples were tested for the selected physico-chemical properties, namely, phosphate, nitrate, pH, electrical conductivity (EC), the five-day biological oxygen demand (BOD5), water temperature, and heavy metals (Chromium (Cr), Lead (Pb), Cadmium (Cd), Zinc (Zn), and Copper (Cu)). These water quality variables were compared by means of ANOVA. Despite the chemical oxygen demand (COD) of Lake Ziway, this study found no significant (p > 0.05) variation in the concentrations of Cu, EC, pH and water temperature between wet and dry seasons in either lake. Variations in Zn concentration and other physico-chemical parameters (EC, BOD5, COD, nitrate, phosphate) between low, medium, and high levels of water hyacinth were significant in both lakes (p < 0.05). Water hyacinth has shown significant phytoremediation nature during wet and dry seasons. The lowest average heavy metal, phosphate, and nitrate concentrations; and significant pH and temperature variations were observed in Lakes Koka and Lake Ziway, among water hyacinth and other grass-infested sites. These findings suggest water hyacinth plant as a promising nature-based solution for removing undesirable chemicals from contaminated water bodies.

Highly conductive laser-induced graphene through the deposition of liquid metal particles for flexible electronics

The rapid and simple fabrication process of laser-induced graphene (LIG) has enabled the creation of flexible sensors for emerging applications such as wearable electronics and intelligent systems. Although LIG can be designed to be a sensitive strain sensor due to the large change in its resistance under deformation, this property can also limit its use as a printed conductor on flexible substrates. Here, we present a versatile technique to enhance the electrical conductivity and resistive heating ability of LIG for use as flexible conductors in printed electronics. The highly conductive traces are prepared by direct writing of LIG onto a polyimide film using a CO2 laser, upon which the functionalized liquid metal (LM)—eutectic gallium indium (EGaIn)—particles are deposited and activated. This results in a ∼400 times increase in electrical conductivity of LIG traces while maintaining mechanical flexibility and manufacturing scalability without the need for soldering. Electromechanical characterization of the LIG-LM traces shows low resistance change (less than 0.3 Ω) under large bending deformations. At the same time, the enhanced electrical conductivity contributes to the resistive heating performance as it reduces the input voltage requirement by ∼15 times to achieve similar surface temperatures compared to pure LIG traces. By combining EGaIn LM with laser-synthesized graphene, we can fabricate flexible hybrid electronics. We demonstrate the practicality of this technique by fabrication of flexible conductors and heating devices with highly customizable patterns.

Improving Iron and Copper Uptake by Changing the Ratios in Root of Vetiver Grass

Phytoremediation using Vetiver grass (VG) has been used in the past few decades all over the world, but the effectiveness of its uptake mechanism in water has less been discussed especially in mixed metal conditions. Hence, the focus of this research was to determine and evaluate the heavy metal removal effectiveness of two heavy metals, copper (Cu) and iron (Fe), based on vetiver grass uptake and toxicity. Three treatments of Fe and Cu mixture were chosen, and individual concentrations act as a control. The vetiver grass at a height of 10 cm and a root length of 25 cm for each treatment was used and harvested on days 0,1, 3, 6 and 7. The roots were randomly cut, oven-dried and used the digestion method to extract the Fe and Cu in the root. From the result, vetiver grass has better Fe and Cu uptake ability in the mixture treatment compared to the individual treatment. Fe uptake is increasing up to 25.3 % in the presence of Cu (mixture 1). Meanwhile, for Cu, mixture 3 is an ideal ratio to increase the Cu uptake by 14.5%. It shows that both Fe and Cu facilitated each other’s uptake in real wastewater conditions. There were also observed minimal toxicity signs such as necrosis throughout the experiment. The appearance of vetiver grass has changed in this experiment starting day 3 and remains yellowish. In conclusion, wastewater that contains a high concentration of Fe than Cu can promise the improvement of both Fe and Cu uptake by vetiver grass. This study benefits researchers that apply phytoremediation to remove heavy metals in wastewater by providing a guideline for Fe and Cu removal by vetiver grass. In future, the study will focus on the mechanism and interaction of Fe and Cu uptake by root

Comparison of Gamma Irradiation Effects on Short Circuit Characteristics of SiC MOSFET Power Devices between Planar and Trench Structures

The short circuit withstand energy (SCWE) variations, and short circuit withstand time (SCWT) variations, of planar and trench silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) power devices are studied after exposure to a total ionizing dose (TID). The results for ON bias are explored. The SCWE and SCWT are studied for planar and trench SiC MOSFET power devices tested for TID with gamma irradiation. A higher degradation phenomenon for the SCWE and SCWT are observed for the planar SiC MOSFET. The physical mechanisms for these variations are analyzed and confirmed by technology computer-aided design (TCAD) simulation.

Desain dan Implementasi Modul Kit Laboratorium Mikrokontroler AT89S52 dengan Single PCB, Portable dan Prospektif

This study aims to design and implement a new design of a single PCB, portable and prospective laboratory kit module. The laboratory kits made are easy to assemble, with relatively small dimensions. and suitable for use in laboratories with limited experimental space and funds. The objectives of this research are (a) creating a microcontroller trainer by creating a series of minimum systems, inputs, outputs, Analog Digital Converter (ADC), (b) system programming using the Keil C51 IDE, (c) measuring and testing trainer performance. The research method starts from making a physical trainer, programming the microcontroller and measuring circuit performance. Pulse width modulation (PWM) of DC motors and the direction of rotation of the motor can be controlled using a potentiometer. The wave that is obtained when the motor is at full speed is in the form of a straight line with a voltage of 9.12 V, while when the motor is at half-full speed, a PWM pulse wave is obtained with a voltage of 4.35 V. The test is carried out based on student practicum work on each input circuit, and the output results are all applications tested successfully as expected.

Removal efficiencies of microplastics of the three largest drinking water treatment plants in Bangladesh

Drinking water treatment plants (DWTPs) are intended to provide safe water to the municipality, typically by treating surface waters from rivers, lakes, and streams. Regrettably, all of these water sources for DWTPs have been reported to be contaminated by microplastics (MPs). Hence, there is an urgent need to investigate the removal efficiencies of MPs from raw waters in the conventional DWTPs anticipating public health concerns. In this experiment, MPs in the raw and treated waters of the three major DWTPs of Bangladesh, having different water treatment processes, were evaluated. The concentrations of MPs in the inlet points of Saidabad Water Treatment Plant phase-1 and 2 (SWTP-1 and SWTP-2), which share a similar water source of the Shitalakshya River, were 25.7 ± 9.8 and 26.01 ± 9.8 items L−1. The third plant, Padma Water Treatment Plant (PWTP) utilizes water from the Padma River and had an initial MP concentration of 6.2 ± 1.6 items L−1. The studied DWTPs, with their existing treatment processes, were found to reduce the MP loads substantially. The final MP concentrations in treated waters of SWTP-1, SWTP-2, and PWTP were 0.3 ± 0.03, 0.4 ± 0.01, and 0.05 ± 0.02 items L−1 with the removal efficiencies of 98.8, 98.5, and 99.2 %, respectively. The considered size range of MP was 20 μm to <5000. Fragments and fibers were the two predominant MP shapes. In terms of polymer, the MPs were polypropylene (PP, 48 %), polyethylene (PE, 35 %), polyethylene terephthalate (PET, 11 %), and polystyrene (PS, 6 %). The field emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX) revealed the fractured and rough surfaces of the remaining MPs, which were also found to be contaminated with heavy metals, like lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), copper (Cu), and zinc (Zn). Hence, additional initiatives are required to remove the residual MPs from the treated waters to safeguard the city dwellers from potential hazards.

Automatic Headlamp Control and Obstacle Detection

The numberof vehicles nowadaysincreasingvery fastly and so is technology. Safety is averyprime factor and has to be considered. vehicles are fitted with lots of safety features. Automatic Upper Dipper beam control and obstacle detection also need to be installed to improve safety to the next level. Thesefeatures are mainly used in nighttime driving or foggy weather or rain. Human eyes are very sensitive to light. when the light suddenly comes in contact with the eyes after darkness, the cornea present in the eyes gets contracted. i.e., human eyes will not be able to see for a short time. it is also called light glare. a vehicle coming from the opposite side with headlight in upper mode causes blind to the driver’s eyes. Insuch cases,there are high chances of occurring an accident. So, an automatic mechanism for controlling the light upper or dipper has to be made todecrease the chances of accidents during nighttime driving. Also, sometimes the driver won’t be able to see any object in nighttime orfoggy or rainy seasons. so, a sensor-based system where obstacle detection is enabled may assist from falling into an event of a crash. these two features assure you a very safe and comfortable drive. The operatingprinciple working and design of PCB is explained in this paper

Impact of soil supplemented with pig manure on the abundance of antibiotic resistant bacteria and their associated genes.

This study was conducted to evaluate the abundance of antibiotic resistant bacteria and their resistance genes from agriculture soil supplemented with pig manure. Uncultivable soil sample was supplemented with pig manure samples under microcosm experimental conditions and plated on Luria-Bertani (LB) agar incorporated with commercial antibiotics. The supplementation of soil with 15% pig manure resulted in the highest increase in the population of antibiotic resistant bacteria (ARB)/multiple antibiotic resistant bacteria (MARB). Seven genera that included Pseudomonas, Escherichia, Providencia, Salmonella, Bacillus, Alcaligenes and Paenalcaligenes were the cultivable ARB identified. A total of ten antibiotic resistant bacteria genes (ARGs) frequently used in clinical or veterinary settings and two mobile genetic elements (MGEs) (Class 1 and Class 2 integrons) were detected. Eight heavy metal, copper, cadmium, chromium, manganese, lead, zinc, iron, and cobalt were found in all of the manure samples at different concentrations. Tetracycline resistance genes were widely distributed with prevalence of 50%, while aminoglycoside and quinolone-resistance gene had 16% and 13%, respectively. Eighteen ARB isolates carried more than two ARGs in their genome. Class 1 integron was detected among all the 18 ARB with prevalence of 90-100%, while Class 2 integron was detected among 11 ARB. The two classes of integron were found among 10 ARB. Undoubtedly, pig manure collected from farms in Akure metropolis are rich in ARB and their abundance might play a vital role in the dissemination of resistance genes among clinically-relevant pathogens.

BMAR

A requirement of cross-modal signal processing is accurate signal alignment. Though simple on a single device, accurate signal synchronization becomes challenging as soon as multiple devices are involved, such as during activity monitoring, health tracking, or motion capture---particularly outside controlled scenarios where data collection must be standalone, low-power, and support long runtimes. In this paper, we present BMAR, a novel synchronization method that operates purely based on recorded signals and is thus suitable for offline processing. BMAR needs no wireless communication between devices during runtime and does not require any specific user input, action, or behavior. BMAR operates on the data from devices worn by the same person that record barometric pressure and acceleration---inexpensive, low-power, and thus commonly included sensors in today's wearable devices. In its first stage, BMAR verifies that two recordings were acquired simultaneously and pre-aligns all data traces. In a second stage, BMAR refines the alignment using acceleration measurements while accounting for clock skew between devices. In our evaluation, three to five body-worn devices recorded signals from the wearer for up to ten hours during a series of activities. BMAR synchronized all signal recordings with a median error of 33.4 ms and reliably rejected non-overlapping signal traces. The worst-case activity was sleeping, where BMAR's second stage could not exploit motion for refinement and, thus, aligned traces with a median error of 3.06 s.

Analysis of temperature characteristics of power transformer withstand short circuit shock for two seconds

The occurrence of a short-circuit fault in a transformer results in a rapid increase in the short-circuit current, and the temperature of the transformer winding rises rapidly. At present, many scholars use analytical formulas to solve for the average temperature of transformer short-circuit for two seconds, but the transient change of the temperature of transformer short-circuit for two seconds is less considered. In order to counter this phenomenon, this paper establishes a two-dimensional planar power transformer model, simulates its fluid-temperature coupling field, and obtains its temperature distribution results. In this thesis, the steady-state fluid-temperature field of 40000 kVA/110 kV oil-immersed power transformers under rated working condition is analyzed. Secondly, on the basis of static analysis, the temperature characteristics after two seconds of short circuit is analyzed numerically. Finally, by comparing the simulated value with the formula calculation value, the calculation results were verified.