Laboratory Simulation Research Articles

Performance Verification and Evaluation of Semi-Active Actuator System Using Quarter Car Lab Simulation with RLDA Data

This study outlines a methodology for determining the durability specifications of electronically controlled dampers by examining performance degradation observed on actual driving roads. It identifies areas of performance decline and the primary causes affecting major actuator dampers. Traditionally, the durability performance of automobile parts has been assessed by calculating damage based on load profiles. However, analyzing actual road conditions is essential because the control commands of electronically controlled suspension systems change in real time according to load conditions. Simulations based on Road Load Data Acquisition (RLDA) use statistically independent representative road surfaces to assess damper deterioration performance. Following this analysis, a rig test of the damper is performed to establish the durability specifications for damper actuator products. The primary form of performance degradation observed was a change in the tensile damping force, which was more substantial than the degradation observed on the compression side. Oil leakage and cavitation were identified as significant influencing factors from a Failure Mode and Effects Analysis (FMEA) perspective. The study concludes that additional design research is necessary, focusing on damper oil and leakage, while also considering the control algorithm’s effects in designing electronically controlled dampers.

A New Iterative Algorithm for Magnetic Motion Tracking

Motion analysis is of great interest to a variety of applications, such as virtual and augmented reality and medical diagnostics. Hand movement tracking systems, in particular, are used as a human–machine interface. In most cases, these systems are based on optical or acceleration/angular speed sensors. These technologies are already well researched and used in commercial systems. In special applications, it can be advantageous to use magnetic sensors to supplement an existing system or even replace the existing sensors. The core of a motion tracking system is a localization unit. The relatively complex localization algorithms present a problem in magnetic systems, leading to a relatively large computational complexity. In this paper, a new approach for pose estimation of a kinematic chain is presented. The new algorithm is based on spatially rotating magnetic dipole sources. A spatial feature is extracted from the sensor signal, the dipole direction in which the maximum magnitude value is detected at the sensor. This is introduced as the “maximum vector”. A relationship between this feature, the location vector (pointing from the magnetic source to the sensor position) and the sensor orientation is derived and subsequently exploited. By modelling the hand as a kinematic chain, the posture of the chain can be described in two ways: the knowledge about the magnetic correlations and the structure of the kinematic chain. Both are bundled in an iterative algorithm with very low complexity. The algorithm was implemented in a real-time framework and evaluated in a simulation and first laboratory tests. In tests without movement, it could be shown that there was no significant deviation between the simulated and estimated poses. In tests with periodic movements, an error in the range of 1° was found. Of particular interest here is the required computing power. This was evaluated in terms of the required computing operations and the required computing time. Initial analyses have shown that a computing time of 3 μs per joint is required on a personal computer. Lastly, the first laboratory tests basically prove the functionality of the proposed methodology.

Investigation of the poloidal magnetic flux at the PF-3 plasma focus within the framework of the program of laboratory simulation of astrophysical jets

Astrophysical jets are collimated plasma outflows observed in diverse astrophysical settings covering seven decades of spatial scale and twenty decades of power, which, nevertheless, share many common features. This similarity over wide range of scales indicates a common core of physics underlying this phenomenon, leading to considerable interest in observational, theoretical and numerical studies. Laboratory astrophysics experiments for simulating astrophysical jets are premised on this common core of physics responsible for multi-scale similarity of jets remaining valid down to laboratory spatial scales of millimeters. Jets formed after the disassembly of the non-cylindrical z-pinch formed in a plasma focus installation have recently been subjects of observational studies. They offer an important complementarity to the main lines of investigations in two respects. Firstly, the multi-faceted role of gravity, radiation, nuclear reactions and related astrophysics is eliminated retaining only a rapid implosion of a compact plasma object in a magnetohydrodynamic environment as a common feature. Secondly, observations can be made using techniques of laboratory plasma diagnostics. In this paper, we report preliminary results regarding presence of poloidal magnetic flux associated with the jets lasting long after the pinch disassembly. This is significant in the context of uncertainty regarding the origin of poloidal magnetic field postulated in several MHD models of astrophysical jet phenomena. Evidence indicating presence of a radial component of electric field suggests existence of plasma rotation as well. These results suggest that more refined experiments can provide insights into the astrophysical jetting phenomena not available from observational astronomy techniques.

Potential amendments of coal fly ash-derived zeolite to beryllium contaminated soil at a legacy waste disposal site

Management of Be contamination using industrial solid waste or solid waste-derived amendments is not well understood. This study investigated the potential of Australian coal fly ash (CFA), derived synthesized zeolite (SynZ) and chitosan-modified zeolite (ModZ), for Be immobilization at the Little Forest Legacy Waste Site (LFLS), a low-level radioactive waste disposal site near Sydney, Australia. In laboratory simulation experiments, the SynZ and ModZ were separately applied as an amendment to both naturally contaminated soil and simulated contaminated (spiked) soil. Different techniques, including pore water (PW), batch desorption, and microbial activities were assessed to provide insight into immobilization mechanisms. Results revealed that amendment of 2% ModZ in soils, substantially decreased Be concentrations in PW (PWBe) ranging from 13.3% to 99.5% across all concentrations of Be. In contrast, PWBe increased while using SynZ, which could be attributed to the increased solubility of different organic-inorganic elements in PW. Moreover, batch desorption using Milli-Q water, simulated acid rainwater [H2SO4/HNO3 = 60/40, (v/v), and 0.11 M acetic acid solution also revealed similar patterns of Be immobilization as found in PWBe analysis. Soil amendments boosted microbial biomass carbon, and phosphorous (MBC,P), along with basal respiration (BRCO2). This indicates increased microbial activities, which are linked with environmental eco-friendliness. This effect was substantially noticed in ModZ-amended soils, exhibiting up to 22 times higher in BRCO2 values compared to unamended soil. Additionally, reduced PWBe was correlated with soluble organic-inorganic elements, desorbed Be in the batch study, and soil MBc. The differences in behavior between SynZ and ModZ underline the importance of carefully studying the various potential amendment materials and the need to evaluate their performance before application in field situations. This study highlights ModZ's effectiveness in eco-friendly Be immobilization, underlining the role of organic functional groups in zeolite architecture, a key factor in controlling Be in soils.

Increasing transparency of computer-aided detection impairs decision-making in visual search.

Recent developments in artificial intelligence (AI) have led to changes in healthcare. Government and regulatory bodies have advocated the need for transparency in AI systems with recommendations to provide users with more details about AI accuracy and how AI systems work. However, increased transparency could lead to negative outcomes if humans become overreliant on the technology. This study investigated how changes in AI transparency affected human decision-making in a medical-screening visual search task. Transparency was manipulated by either giving or withholding knowledge about the accuracy of an 'AI system'. We tested performance in seven simulated lab mammography tasks, in which observers searched for a cancer which could be correctly or incorrectly flagged by computer-aided detection (CAD) 'AI prompts'. Across tasks, the CAD systems varied in accuracy. In the 'transparent' condition, participants were told the accuracy of the CAD system, in the 'not transparent' condition, they were not. The results showed that increasing CAD transparency impaired task performance, producing an increase in false alarms, decreased sensitivity, an increase in recall rate, and a decrease in positive predictive value. Along with increasing investment in AI, this research shows that it is important to investigate how transparency of AI systems affect human decision-making. Increased transparency may lead to overtrust in AI systems, which can impact clinical outcomes.

Complex left atrial appendage closure using 3D printing system simulation in a patient with mitral prosthetic valve: a case report

Abstract Background Left atrial appendage (LAA) closure (LAAc) has emerged as a safe and effective alternative to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation (AF) and contraindications to OAC. Case Summary A 61-year-old woman with permanent atrial fibrillation (AF) and a history of mitral surgery replacement with mechanical prosthesis was referred to our cardiology department to undergo left atrial appendage (LAA) closure (LAAc). The preoperative computed tomography (CT) revealed that the ostium of the left atrial appendage was close to the mitral prosthesis ring. As a result of the difficult LAA morphology a CT-image based virtual model was created, then a 3D printing model was prepared in our laboratory and procedure simulation was performed with the two different LAA occlusion devices (plug- vs. pacifier like models) to see which one was more suitable for the patient anatomy. Discussion In this case of complex LAAc in a patient with mechanical prosthetic mitral valve with the use of a 3D-printed model has guided prosthesis selection and device sizing reducing procedure time and complications.

The Attachment of Juvenile Mussels via Byssus Weakened by Contaminated Polyethylene Fibers

In the process of mussel farming, the rope for attachment is indispensable, as it provides a stable attachment environment for mussel seedlings, directly affecting their survival rate and growth quality. The objective of this study is to examine the contamination of ropes, composed of polyethylene fibers, by heavy metals and polycyclic aromatic hydrocarbons (PAHs) after three years of deployment and to assess its influence on the attachment and locomotion behaviors of juvenile mussels. Utilizing a laboratory simulation of the seedling wrapping process, a comparative analysis was conducted to evaluate the number of juvenile mussels attached and their movement distances when exposed to contaminated old ropes versus uncontaminated new ropes. The findings indicated that the old ropes markedly diminished the attachment rate of juvenile mussels and heightened their movement distances. In particular, juvenile mussels utilizing old ropes exhibited a final attachment rate of 15.0% and an average movement distance of 0.86 cm, whereas those using new ropes achieved a final attachment rate of 96.7% with an average movement distance of 0.26 cm. Further inspection found that heavy metals and PAHs were present in the old rope, among which the concentrations of Zn (17.127 μg/g) and Pb (22.905 μg/g) in heavy metals were high, and the concentrations of Phe (5.53 μg/kg), Fla (6.35 μg/kg), and Pyr (5.17 μg/kg) in PAHs exceeded the detection limits, which were the main source of pollution. This research underscores the potential risk that heavy metal and PAHs contamination pose to the health of juvenile mussels and the profitability of aquaculture, emphasizing the critical need for the regular replacement of clean ropes.

Advancing the Understanding of Microplastic Weathering: Insights from a Novel Polarized Light Scattering Approach.

Weathering is a significant process that alters the properties of microplastics (MPs) and consequently affects their environmental behaviors. In this study, we introduced a novel approach based on polarized light scattering technique, which offers advantages in terms of rapid, high-throughput, and submicron-sized detection. This technique was successfully applied to characterize the weathered MPs after a 180-day laboratory simulation of coastal environments. By employing polarization measurements, we obtained a 46-dimensional matrix data set for the weathered MP fragments and subsequently processed them using a backpropagation neural network. The successful extraction of effective polarization pulses confirmed the presence of MP fragments within the size range of 0.2-60 μm, yielding total accuracies for size classification ranging from 78.9 to 86.9%. Furthermore, this technique achieved an overall accuracy of 93.8% in classifying MPs with different weathering degrees and polymer types, revealing polarization parameters associated with size and morphological changes play a dominant role in characterizing the weathering process of MPs. Compared with conventional approaches, the novel polarized light scattering approach holds great promise for rapid, high-throughput, and accurate characterization of MPs with small sizes. The findings of this study provided new insights into how MPs change after long-term weathering in aquatic environments.

Research on Safety Management of University Laboratories Based on Isolation Forest Algorithm

This paper mainly discusses the application of the Isolation Forest Algorithm in the safety management of university laboratories. Through the analysis of the current situation of safety management in university laboratories, the deficiencies of traditional management methods are expounded. Then, the principle and advantages of the Isolation Forest Algorithm are introduced in detail, and the effectiveness of this algorithm in the abnormal detection of laboratory safety is verified through experiments in a simulated laboratory environment. The experimental results show that the Isolation Forest Algorithm can quickly and accurately detect abnormal situations in the laboratory, providing a new and effective means for the safety management of university laboratories.

Using Eye-Tracking to Evaluate Novel Augmented Reality Applications for Maritime Operations

This paper presents the developments across a multi-year collaborative industry-academia R&D project designing and testing novel Augmented Reality (AR) solutions for differing maritime operations and work tasks. We describe the step-wise approach taken in our Human Factors testing program exploring the effects of AR on maritime operators. This paper focuses specifically on our empirical simulator laboratory experiments using differing data collection designs, tools and operational scenarios to investigate operator Situation Awareness, cognitive workload, performance and usability. Moving from comparatively rudimentary measures using static scenarios, desktop data collections and post hoc video analysis to implementing eye-tracking and automated object identification in dynamic scenarios and full-mission simulated environments, we present an overview of how our testing program has evolved and lessons learned. Further, we discuss ongoing research and future plans to better understand the effects of AR on maritime end-users to implement human-centred solutions more effectively in maritime settings.

CO Dissociation Induced by 1 keV/u Ar2+ Ion

CO is one of the important molecules in dense molecular clouds, and its dissociation induced by cosmic ray heavy ions is a fundamental process for molecular breaking up and rearrangement in astronomical networks. Extensive laboratory simulations are required to understand molecular evolution in astrophysical contexts. Here, we investigate the CO dissociation induced by 1 keV/u Ar2+ using cold target recoil ion momentum spectroscopy. Kinetic energy release for double electron capture Ar2++CO→Ar0+C++O+ and transfer ionization Ar2++CO→Ar++C++O++e− was obtained. The dissociation mechanisms are attributed to different KER distributions. The autoionization process is identified below the CO2+ double ionization threshold.

The soil-air interfacial migration process of volatile PFAS at the contaminated sites: Evidence from stable carbon isotopes with CSIA

Volatile per- and polyfluoroalkyl substances (PFAS) are prone to transport among various environmental media, with the soil-air interfacial migration process being an important pathway that significantly influences their environmental fate. To assess the migration and transformations of target volatile PFAS at contaminated site using compound-specific stable isotope analysis (CSIA), it is necessary to understand the isotopic fractionation that occurs during their transfer from soil to air. We have established methods for pre-treatment and GC/CSIA analysis methods of target volatile PFAS in soil and air samples and ensured the accuracy of carbon isotope analysis. GC/IRMS δ13C measurements showed optimal precision at instrumental response above 1.35–2.75 Vs, with recommended minimum on-column C levels of 1.67–5.00 nmol for target volatile PFAS. Stable carbon isotope fractionation factors related to the soil-air interfacial migration process for target volatile PFAS were determined by performing laboratory simulations. The observed εsoil-air values are all negative, suggesting that the soil-air interfacial migration process for target volatile PFAS is kinetic fractionation, the removal of molecules containing lighter isotopes. By comparing the simulated and experimentally observed δ13C (‰) values of target volatile PFAS, we found consistent trends in the soil and inverse trends in the air. These δ13C (‰) values and the related isotope fractionation model provide valuable insights into the isotopic behavior of target volatile PFAS during soil-air interfacial migration process, aiding in the assessment of their environmental fate.

Water-Rock Interaction Mechanisms and Hydrochemical Evolution in the Underground Reservoirs of Coal Mines.

Coal-mine underground reservoirs play pivotal roles in water purification through water-rock interactions; however, underlying mechanisms associated with water-rock interactions remain unclear to date. To address this issue, this study considered the underground reservoirs of the Daliuta coal mine, Shendong to conduct the analysis. Through onsite sampling and laboratory simulation experiments, along with hydrochemical-diagram-based analysis, multivariate statistical analysis, and hydrogeochemical simulations, the sources and evolutions of major ions associated with the water of the underground reservoirs were elucidated. Results revealed that the suspended-solid content, turbidity, electrical conductivity, and total dissolved solid concentration in the water at the outlet of the underground reservoirs decreased significantly compared to corresponding values at the inlet. Alteration in the hydrochemical type of water was observed from the Cl·HCO3-Na·Ca, Cl-Na·Ca·Mg, and Cl·SO4-Na types at the inlet of the reservoirs to SO4·Cl-Na at the outlet of the reservoirs. Further, the primary hydrogeochemical processes carried out along the water flow path in the underground reservoirs included mineral dissolution (including halite, silicate, calcite, gypsum, and anhydrite dissolution), pyrite oxidation, cation exchange, and clay-mineral adsorption. Water-rock interactions in the underground reservoirs can be categorized into three stages. The first stage was dominated by dissolution and oxidation, resulting in decreased water pH and overall increased concentrations of total dissolved solids along with major ions in the water. The second stage was dominated by clay-mineral adsorption and cation exchange, resulting in increased water pH and overall concentrations of Na+ and K+ as well as decreased concentrations of Ca2+, Mg2+, and total dissolved solids in the water body. The third stage was characterized by weak water-rock interactions, wherein the concentrations of total dissolved solids along with major ions, as well as the pH of the water stabilized. Thus, our research findings provide important theoretical references for understanding water-purification mechanisms and water-storage-duration optimization in coal-mine underground reservoirs.

Response of the photosynthetic characteristics and antioxidant system of Suaeda salsa to the changes of underground brine depth.

Water and salt conditions are key factors influencing vegetation growth on shell island in the Yellow River Delta. However, the effects of the depth of underground brine on the photosynthetic characteristics and antioxidant system of halophytes remain unclear. The laboratory simulation experiment was carried out to investigate the effect of the changes of underground brine depth on Suaeda salsa using four levels of groundwater: 0 cm, 15 cm, 30 cm and 45 cm. The results showed that different underground brine depths had significant impacts on the photosynthetic characteristics and antioxidant system of S. salsa, and 0-30 cm underground brine depth was suitable for S. salsa growth. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), light utilization efficiency (LUE) and carboxylation efficiency (CE) of S. salsa increased first and then decreased with increasing depth of underground brine. The stomatal limitation value (Ls) and WUE of S. salsa reached the peak value at the groundwater depth of 0 cm, and water use efficiency was reduced by 19.4%, 8.0% and 8.6% at 15 cm, 30 cm, and 45 cm, respectively, compared to the 0 cm treatment. With the deepening of underground brine depth, the value of LUE and CE firstly increased and then decreased, and reached the peak value when the depth was 30 cm. The antioxidant enzyme (SOD, POD and CAT) activities of S. salsa decreased and then increased with the increase of underground brine depth. The enzyme activities were the lowest when the underground brine depth was 30 cm. As the groundwater depth increased, MDA content decreased and then increased. The highest degree of membrane peroxidation in S. salsa leaves was observed at the depth of 45 cm. Our study reveals that the antioxidant capacity of S. salsa was weakened at the underground brine depth of 45 cm and the growth of S. salsa was inhibited.

How to alleviate seasonal limitations on water quality in farmland ditches? The importance of plant selection and configuration

In subtropical monsoon climate regions, traditional plants in constructed wetlands such as farmland ditches underperform in cold months, detracting from both purification capacity and esthetic appeal. To alleviate this weakness, this study introduced Phalaris arundinacea, a species with strong adaptability and cold tolerance, into a plant community dominated by Phragmites australis, constructing an ingenious composite plant community for year‐round water quality restoration and enhancement of attractiveness. First, laboratory simulations revealed significant seasonal differences in the removal rates of ammonia nitrogen (NH3‐N), total nitrogen (TN), and total phosphorus (TP) by the P. arundinacea community and P. australis community under different pollutant loads. Phragmites australis showed superior NH3‐N and TN removal capabilities from May to October, whereas P. arundinacea excelled in the rest of the months throughout the year. For TP removal, P. australis outperformed P. arundinacea from July to October, while P. arundinacea was more effective from January to May. We then verified this in rear farmland ditches, where P. australis were strategically partial substituted with P. arundinacea (Partial Replacement Treatment [PRT]), and compared it with unchanged farmland ditches (Control Treatment). We found that PRT enhanced decontamination efficiency over the year, especially significantly improving the water quality during colder months. Hence, this study advocates a novel strategy for effective annual decontamination and maintenance of wetlands such as farmland ditches, highlighting the importance of seasonally adaptive plant communities for water restoration. This transformative approach dramatically advances the field of wetland management, insisting on the important role of cold‐resistant species for year‐round ecosystem service optimization.

Radiofrequency Diagnostic of the Decaying Plasma in the “Gigantic” Coaxial Line at the Large Plasma Device

At the large-scale Krot facility (Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences), a new device was developed for laboratory simulations of the effects of the interaction of ultrawideband electromagnetic pulses with the partially ionized atmosphere and ionosphere: the “gigantic” coaxial line with a length of 10 m and diameter of 1.4 m that is filled by the decaying plasma of the inductive discharge. Two radiofrequency methods of wave diagnostics used in the device are described, the cutoff method and the wave interferometer, which can be used to determine the electron density of the plasma in the line in a wide range of values, Ne = 107–1011 cm–3. The measurement results are compared with the values obtained by the contact diagnostic, a probe with a microwave resonator. The interferometric method is implemented taking into account the nonuniform distribution of plasma density both along and across the transmission line, which, in the working range of pulsed and continuous diagnostic signals, is an oversized waveguide. The specific features of application and the limitations of the contact (probe) and contactless (wave) methods of diagnostics are discussed, taking into account the nonuniform plasma distribution in the coaxial line and the specific features of its construction.

Comparison of the Effect of Using Virtual Laboratory Based on PhET Simulation and Real Laboratory in Improving Mastery of Electronic Concepts of Physics Education Students

This study aimed to compare the mastery of electronic concepts among physics education students using a constructivist virtual laboratory (PhET Simulation) and a real constructivist laboratory. The importance of this research lies in the potential of virtual laboratories as an alternative to physical ones, especially when resources are limited. The research employed a quasi-experimental design with a matching-only posttest-only control group. The sample consisted of 68 physics education students from UIN Alauddin Makassar, divided into two groups: one using PhET Simulation (34 students) and the other using real laboratories (34 students). Data were collected through multiple-choice tests designed to measure concept mastery, analyzed using descriptive statistics and inferential tests such as t-tests. The results showed no significant difference in concept mastery between students using PhET Simulation and those using real laboratories (t =-0.167, p= 0.868). Both methods were equally effective in enhancing students’ understanding of electronics. The novelty of this study lies in directly comparing the two laboratory approaches within a constructivist framework. This finding suggests that virtual laboratories can serve as a viable alternative to real laboratories in supporting concept mastery, offering flexibility and resource efficiency. The implications of the study are particularly relevant for educational institutions with limited access to physical laboratories, as PhET Simulation provides a cost-effective solution without compromising learning outcomes.

Analisis Implementasi Kebijakan Pembelajaran Jarak Jauh Program Diploma IV Pada Masa Pandemi Covid 19 di Sekolah Tinggi Ilmu Pelayaran

At the start of the COVID-19 pandemic, all aspects of life were changed, including education. Distance learning is now preferred over face-to-face. The purpose of this study is to evaluate how the distance learning policy is implemented at the College of Shipping during the COVID-19 pandemic. This study also looks at the factors that support and hinder the implementation of the policy, as well as the strategies needed. In this study, a descriptive qualitative method was used. The informants in this study included Structural Officials as Policy Makers, Functional Officials, Lecturers, and Cadets working in policy implementation. This research collected data through observation and interviews. George C Edward III's theory was used as a reference, which states that policy implementation is influenced by four (4) factors: communication, resources, disposition, and bureaucratic structure. The results showed that, during the COVID-19 pandemic, the distance learning policy of the Diploma IV program at the College of Shipping was implemented quite well. However, there are shortcomings in its implementation. Supporting factors, such as the implementation of distance learning in an effort to accelerate the handling of the Covid-19 outbreak, are very helpful. The distance learning policy is considered the best option to maintain education in the midst of a pandemic. The commitment of leaders and communication with implementing staff is good enough. One thing that hinders is the lack of coordination between implementing staff (bureaucracy) when tracking the implementation of distance learning. This is because the SOP for distance learning is not yet available. Lecturers and cadets still complain about the internet network that sometimes experiences delays and sound that suddenly disappears, which disrupts the delivery of materials and consumes resources. Lecturers also complain about the skills of cadets in using simulator equipment, Lab Workshop, and other simulators.

CFD–DEM comparison of slurry infiltration in laboratory column tests and in real-world tunnelling

Slurry infiltration and filter cake formation are critical for excavation surface stability in slurry shield tunnelling. Laboratory column tests are frequently adopted to study macroscopic infiltration. However, these tests, in a vertical orientation and confined by an impermeable cylindrical boundary, may not be a good representation of horizontal infiltration into an unbounded stratum in real-world tunnelling. In this paper, a more realistic slurry pressure balance (SPB) tunnelling model was created to overcome the limitations of simulated laboratory column tests. Coupled computational fluid dynamics (CFD)–discrete element method (DEM) numerical simulations were carried out to study the slurry infiltration into sand for this model and compare the results with the conventional laboratory column test model. Both models produced the same types of filter cakes. The SPB tunnelling model yielded larger infiltration distances and ranges, but a lower normalised permeability in the sand region in front of the tunnel face. The fluid pressure within this region dissipated much faster in the SPB tunnelling model, resulting in rapid velocity decreases and a faster infiltration process. Although the SPB tunnelling model is more representative of real-world tunnelling, the conventional laboratory column test is conservative, producing similar types of filter cakes over a longer timeframe.

Research on the monitoring system for induced voltage and ground current of 27.5 kV cable sheath in railways

PurposeThe purpose of this study is to address the deficiency in safety monitoring technology for 27.5 kV high-voltage cables within the railway traction power supply by analyzing the grounding methods employed in high-speed railways and developing an effective monitoring solution.Design/methodology/approachThrough establishing a mathematical model of induced potential in the cable sheath and analyzing its influencing factors, the principle of grounding current monitoring is proposed. Furthermore, the accuracy of data collection and alarm function of the monitoring equipment were verified through laboratory simulation experiments. Finally, through practical application in the traction substation of the railway bureau on site, a large amount of data were collected to verify the stability and reliability of the monitoring system in actual environments.FindingsThe experimental results show that the designed monitoring system can effectively monitor the grounding current of high-voltage cables and respond promptly to changes in cable insulation status. The system performs excellently in terms of data collection accuracy, real-time performance and reliability of alarm functions. In addition, the on-site trial results further confirm the accuracy and reliability of the monitoring system in practical applications, providing strong technical support for the safe operation of high-speed railway traction power supply systems.Originality/valueThis study innovatively develops a 27.5kV high-voltage cable grounding current monitoring system, which provides a new technical means for evaluating the insulation status of cables by accurately measuring the grounding current. The design, experimental verification and application of this system in high-speed railway traction power supply systems have demonstrated significant academic value and practical significance, contributing innovative solutions to the field of railway power supply safety monitoring.