Disassembly Analysis Research Articles

AND/OR graph generation for disassembly analysis: Deeply-nested subassemblies represented by a hypergraph

AND/OR graph generation for disassembly analysis: Deeply-nested subassemblies represented by a hypergraph

The effect of low-temperature starting on the thermal safety of lithium-ion batteries

With the widespread application of lithium-ion batteries (LIBs) in the field of energy equipment, their probability of starting or operating in low-temperature environments is also increasing. However, there is currently a lack of research on the changes in thermal safety of batteries after use in corresponding environments. In this work, the thermal safety performance, degradation mechanisms and evaluation method of LIBs at low-temperature start-up conditions are studied. The results show that starting at low temperature leads to the decrease of cell capacity. Electrochemical characterization and cell disassembly analysis indicate that the loss of active lithium ions is mainly caused by the evolution of lithium and the growth of solid electrolyte interface films. In addition, the low-temperature startup results in the decrease of thermal runaway (TR) onset temperature and the advance of TR time. In order to quantitatively evaluate the safety state of the LIBs, an evaluation model based on Informer algorithm is established. The model extracts the discharge capacity, discharge energy and dV/dQ as aging characteristic parameters, and extracts TR temperature as thermal safety characteristic parameters. The data set is processed by cubic spline interpolation. After training and verification, the accuracy of the model reaches 80 %.

Fault diagnosis and analysis of a 110 kV transformer

This paper aims to provide valuable insights and assistance for ensuring the safe operation of a 110 kV main transformer by conducting an in-depth analysis of tap changer breather oil leakage defects. By employing transformer testing, disassembly analysis, and other methods, this study successfully identifies and prevents the possibility of transformer failure. The analysis reveals that the deformation of the transformer winding is caused by insufficient short-circuit resistance, which leads to the deformation of the medium-voltage windings under the continuous action of electrodynamic forces during near-area short-circuit currents. Near-area short-circuits are a significant contributing factor to transformer failures. Therefore, it is recommended to enhance operation and maintenance management for older main transformers and optimize protection settings to reduce the risk of near-area short-circuit failures, thus ensuring the safe and stable operation of the main transformer.

Multiscale biophysical analysis of nucleolus disassembly during mitosis

During cell division, precise and regulated distribution of cellular material between daughter cells is a critical step and is governed by complex biochemical and biophysical mechanisms. To achieve this, membraneless organelles and condensates often require complete disassembly during mitosis. The biophysical principles governing the disassembly of condensates remain poorly understood. Here, we used a physical biology approach to study how physical and material properties of the nucleolus, a prominent nuclear membraneless organelle in eukaryotic cells, change during mitosis and across different scales. We found that nucleolus disassembly proceeds continuously through two distinct phases with a slow and reversible preparatory phase followed by a rapid irreversible phase that was concurrent with the nuclear envelope breakdown. We measured microscopic properties of nucleolar material including effective diffusion rates and binding affinities as well as key macroscopic properties of surface tension and bending rigidity. By incorporating these measurements into the framework of critical phenomena, we found evidence that near mitosis surface tension displays a power-law behavior as a function of biochemically modulated interaction strength. This two-step disassembly mechanism maintains structural and functional stability of nucleolus while enabling its rapid and efficient disassembly in response to cell cycle cues.

Disassembly analysis of hot-melt adhesive in mechanical joints

The mechanical properties of a commercially available hot-melt adhesive (HMA) have been studied under different environmental and loading conditions. To date, disassembly analyses including triggering features, design parameters, and time have not been fully investigated in the literature. In this study, experimental parametric studies have been performed on single lap joints considering the geometric features of the joint and a combination of thermo-mechanical effects. Disassembly time has been assessed through experimental analysis, considering variations in geometry, the use of alternative heat sources and different load conditions. Use of a heat gun as the heat source was found to lead to the highest variation in disassembly time compared to a static climatic chamber (i.e., industrial oven). In relation to the joint geometry, the disassembly time was mostly affected by the overlap length rather than the type or thickness of the base material. The outcomes of this study will drive the design of adhesive joints in mechanical applications, providing design-for-disassembly guidelines for the development of reversible joints employing hot-melt adhesives.

Disassembly and Repairability of Mechatronic Products: Insight for Engineering Design

Abstract Designing mechatronic products requires interdisciplinary skills and as products become more complex, the design of mechatronic systems plays a critical role. To minimize waste production and pollution, a shift toward a circular economy is necessary, with mechatronic products being particularly impacted by such policies. Repairing plays a key part in achieving a circular economy. Through repairability, the product lifespan can be extended, and combined with maintenance the rate of product replacement can be reduced. Within this context, the goal of this paper is to propose a design methodology (based on the EN 45554:2020 standard) for generating and implementing eco-design rules for disassembly and repair. The methodology has four phases, the first one is the identification of target components (those that are more likely to fail during the lifespan). The second phase encompasses the experimental disassembly analysis which can be manual or virtual. The third phase is the assessment of the disassemblability index which includes the analysis of parameters that affect the disassembly phase. The last phase is the implementation of the eco-design methodology for all the components that do not meet the minimum repairability requirements. A case study of electro-mechanical ovens is presented, targeting replaceable components. The results show that the use of this framework and the eco-design actions derived from it are successful in improving the repairability of the product and increasing the disassemblability index (30% on average) through a virtual analysis. A sensitivity analysis has been conducted to study the impact of parameter weight modification. This research contributes to advancing repairability and supporting the circular economy paradigm in mechatronic product design.

Analysis of an Abnormal Secondary Voltage Accident of Capacitive Voltage Transformer

Capacitive Voltage Transformer (CVT) is an important measurement and protection equipment in power system, which has the characteristics of high electrical strength, large insulation margin and reliable operation. During the operation of CVT, its upper and lower capacitors, compensation reactors, lightning rods and other components often have faults. The faults of CVT can be found in time by judging the secondary voltage value. In this paper, an abnormal secondary voltage fault of CVT is introduced. Combined with test and disassembly analysis, it is determined that the fault is caused by breakdown of capacitor unit. Through fault simulation, this paper studies the typical CVT faults and the change law of secondary voltage, and puts forward the threshold of the secondary voltage abnormal alarm of CVT, providing important reference for CVT online monitoring.

Evolution of grounding failure‐insulation failure of 10 kV cable joints: Prerequisites of an explosion in enclosed cable trench

AbstractAn explosion accident in an enclosed cable trench caused by the discharge of 10 kV three‐phase cable joints is discussed. Combined with the disassembly analysis, the fault recording data analysis, and the validation of experiment, the evolution of the cable joint fault is deduced and discussed. The results show that the trigger of the cable joint fault is the creepage discharge at the cross‐linked polyethylene–silicon rubber insulation interface. This results in the partial breakdown and the grounding failure of three‐phase cable joints. Under the long‐term floating potential and current thermal effect, the insulations are gradually ablated and decomposed into a large amount of combustible gas. Finally, the accumulated combustible gas is ignited by the arc caused by a three‐phase short circuit at the moment of the reclosing operation. The analytical method and conclusions proposed in this paper can provide suggestions and guidance to prevent analogous distribution network cable joint fault accidents.

Degradation mechanism of all‐solid‐state lithium‐ion batteries with argyrodite Li7−xPS6−xClx sulfide through high‐temperature cycling test

AbstractSulfide‐based all‐solid‐state lithium‐ion batteries (LIBs) are promising replacements for conventional liquid electrolyte LIBs. However, their degradation mechanisms and analysis methods are poorly understood. Herein, the degradation mechanism of an argyrodite‐type sulfide‐based all‐solid‐state prototype LIB cell is reported. Furthermore, an analysis method for all‐solid‐state batteries using charge/discharge cycle tests at 100°C followed by the disassembly analysis of cells before and after accelerated degradation tests is reported. Based on the findings of this study, the degradation of the prototype cell is classified as follows: (i) solid electrolyte (SE) oxidation in the positive electrode, which recovers battery capacity and increases resistance; (ii) SE reduction in the negative electrode, which decreases capacity; (iii) lithium deposition on/in the negative electrode, which decreases capacity; and (iv) capacity loss of the positive electrode, which decreases capacity. These degradation reactions appear to occur simultaneously. These findings are expected to aid the development of sulfide‐based solid‐electrolyte LIBs with improved safety and energy densities.

Partial Discharge Detection and Defect Location Method in GIS Cable Terminal

The complex structure of gas-insulated switchgear (GIS) cable terminals leads to serious electric field concentration, which is a frequent fault position of a high-voltage cable system. At present, due to the differences in the frequency bands of sensors, various partial discharge detection technologies have certain differences in their scope of application and anti-interference performance, resulting in a low defect detection rate in GIS cable terminals. In this paper, a comprehensive diagnosis scheme is proposed, which integrates transient earth voltage (TEV), ultra-high frequency (UHF), high frequency (HF), and ultrasonic methods. Two abnormal discharge defects of GIS terminals in two 220 kV substations in Tianjin were tracked and monitored, and the joint diagnosis was carried out using the proposed scheme; the type of discharge defect and the phase sequence of the defect were determined, and the UHV was employed to precisely locate and analyze the defect source. Finally, through the disassembly analysis and electric field simulation of the GIS cable terminal, the accuracy and effectiveness of the discharge detection and location method were verified, providing a typical detection demonstration for the defect diagnosis of a GIS cable terminal.

Research on compound faults identification of aeroengine inter-shaft bearing based on CCF–Complexity–VMD–SVD

Inter-shaft bearing is an important component of dual-rotor aeroengine and it is difficult to extract fault characteristics and identify a fault type. Therefore, the paper has proposed a method (CCF–Complexity–VMD–SVD) combining information fusion, Complexity parameter of Hjorth parameters, variational mode decomposition (VMD), and singular value decomposition (SVD). Firstly, to fully embody fault characteristic information, the method has established the cross-correlation function (CCF) of homologous acceleration information from the casing of one of the aeroengines (acceleration signals collected from the same section at the same moment in orthogonal directions) to blend homologous information, reinforce fault characteristic components, and lessen the influence of noise. Secondly, considering the great influence of signal complexity on the extraction of fault characteristics and the Complexity parameter of Hjorth parameters can express the complexity of signals better, the Complexity parameter of Hjorth parameters is placed into the fault characteristic extraction of inter-shaft bearing. The Complexity parameter is applied to optimize the number of layers and central frequency of VMD. Thirdly, signals are denoised through SVD to further lessen the influence of noise on characteristic extraction. Finally, frequency spectrum (FS) of signal denoised is used to make characteristic extraction and fault identification of compound faults of inter-shaft bearing. The result of comparative analysis with other methods has further illustrated the proposed method CCF–Complexity–VMD–SVD that can actualize the effective characteristic extraction of compound faults and precise identification in the early stage of fault based on vibration signals from casing of aeroengine. The performance of engineering appliance of the proposed method has been further verified through fault analysis of disassembly for the aeroengine.

A multi-variable analysis of aircraft structure disassembly ‐ A technico-economic approach to increase the recycling performance

Despite international efforts in maximizing products recycling, complex product reprocessing poses a considerable threat on sustainable development on a macro scale. Thousands of aircrafts reach their End-of-Life each year with most of their components ending up in graveyards and landfill. Airframe disassembly, as a main step, is a complex process in terms of the required effort versus the regained values. This research proposes a disassembly planning model to evaluate the ease of disassembly for complex products. Three key disassembly parameters are employed including time, difficulty and, material compatibility to evaluate the efficiency of the disassembly strategies based on technical, economic and environmental criteria. A mathematical model is presented to find the most efficient solution based on the defined criteria. A mid-range airliner stabilizer was selected as a case study to validate the efficiency of the proposed method. The analysis includes airframe disassembly site visits, aircraft documentation analysis, interviews with experts and disassembly examination over a three-year period. The results from the proposed method shows the selected disassembly plan is 65% easier to perform, 85% less time-consuming and allows the user to gain more material recovery than conventional technics. The scalable findings of this research can be useful to increase the efficiency of the disassembly task on complex products particularly of interests to the disassembly sites, product owners and OEMs.

Disassembly system design and analysis with environmental and economic parts selection using life cycle inventory database by input-output tables

Disassembly system design and analysis with environmental and economic parts selection using life cycle inventory database by input-output tables

Spatiotemporal Proteomic Analysis of Stress Granule Disassembly Using APEX Reveals Regulation by SUMOylation and Links to ALS Pathogenesis

Stress granules (SGs) are cytoplasmic assemblies of proteins and non-translating mRNAs. Whereas much has been learned about SG formation, a major gap remains in understanding the compositional changes SGs undergo during normal disassembly and under disease conditions. Here, we address this gap by proteomic dissection of the SG temporal disassembly sequence using multi-bait APEX proximity proteomics. We discover 109 novel SG proteins and characterize distinct SG substructures. We reveal dozens of disassembly-engaged proteins (DEPs), some of which play functional roles in SG disassembly, including small ubiquitin-like modifier (SUMO) conjugating enzymes. We further demonstrate that SUMOylation regulates SG disassembly and SG formation. Parallel proteomics with amyotrophic lateral sclerosis (ALS)-associated C9ORF72 dipeptides uncovered attenuated DEP recruitment during SG disassembly and impaired SUMOylation. Accordingly, SUMO activity ameliorated C9ORF72-ALS-related neurodegeneration in Drosophila. By dissecting the SG spatiotemporal proteomic landscape, we provide an in-depth resource for future work on SG function and reveal basic and disease-relevant mechanisms of SG disassembly.

Failure Analysis of 500kV Gapless MOA

This paper analyzes the cause of a 500kV gapless MOA fault in a substation. The appearance inspection and disassembly analysis of the arrester are carried out. Combined with the protection action, the fault cause of the arrester is analyzed. It is found that the fault is caused by the side flashover failure of the local resistor piece of the line arrester due to the steepness of the lightning invasion wave is large. When the line is reclosed, the lower section bears the over-voltage, resulting in the damage of some resistors, and then causes the pressure release. Based on the analysis the paper puts forward some corresponding operation and maintenance measures.

Analysis and Treatment of abnormal Expander Oil Level in a 220kV Current Transformer

A disassembly analysis and treatment of abnormal oil level fault of current transformer expander is introduced in this article. After returning to the factory for a comprehensive electrical test and investigation, it was found that the reason was the wrong wiring of the zero screen lead. Recommendations for quality control and preventive measures and operation and maintenance procedures for this type of electrical equipment are given in this paper, providing a basis for further research.

A case study on an explosion accident of a 110 kV porcelain housed MOA

A metal oxide arrester (MOA) accident occurred in a tropical coastal area is studied in this paper. The control test and disassembly analysis for the MOAs in the accident group and the control group were conducted. It was considered that the varistors of the MOA were deteriorating. Although the performance of the zinc oxide (ZnO) varistor is qualified, its side insulation glaze has defects. The leakage current under U1mA and 0.75 U1mA have exceeded the standard requirements due to the decrease of insulation performance. An electrothermal model of the MOA was constructed. The root-mean-square (RMS) value of the voltage across the varistor column and the RMS of leakage current flowing through the varistor were obtained through simulation. The heating power was calculated as the heat source input of the thermal circuit model to calculate the temperature of the varistor. It was verified that the electrolyte deposited on the surface of the porcelain house due to salt spray formed a dry area after being affected by moisture, because of the uneven potential distribution, the radial current flowing to the varistors through the coupling capacitor on the surface of the porcelain house increased sharply, and it caused the varistor to generate a large amount of heat in extreme condition. The side insulation glaze of the varistor was damaged by frequent heating effect. Eventually, the internal flashover occurred in the MOA, and the internal pressure rose sharply then broke through the explosion-proof film, causing an accident.

Spatio-Temporal Proteomic Analysis of Stress Granule Disassembly Using APEX Reveals Regulation by SUMOylation and Links to ALS Pathogenesis

Cytoplasmic stress granules (SG) form in response to a variety of cellular stresses by phase-separation of proteins associated with non-translating mRNAs. SG provide insight into the biology of neurodegeneration, including amyotrophic lateral sclerosis (ALS) because they approximate some of the molecular conditions for nucleation of insoluble aggregates in neuropathological inclusions. Whereas much has been learned about SG formation, a major gap remains in understanding the compositional changes SG undergo during normal disassembly and under disease conditions. Here, we address this gap by proteomic dissection of SG temporal disassembly sequence, using multi-bait APEX proximity-proteomics. We discover 109 novel SG-proteins and characterize at proteomic resolution two biophysically distinct SG substructures. We further demonstrate that dozens of additional proteins are recruited to SG specifically during disassembly, indicating that it is a highly regulated process. The involved proteins link SG disassembly, to mitochondrial biology and the cytoskeleton. Parallel analysis with C9ORF72-associated dipeptides, which are found in patients with ALS and frontotemporal dementia, demonstrated compositional changes in SG during the course of disassembly and focused our attention on the roles SUMOylation in SG disassembly. We demonstrate that broad SUMOylation of SG-proteins is required for SG disassembly and is impaired by C9ORF72-associated dipeptides, representing an unexplored potential molecular mechanism of neurodegeneration. Altogether, out study fundamentally increases the knowledge about SG composition in human cells by dissecting the SG spatio-temporal proteomic landscape, provides an in-depth resource for future work on SG function and reveals basic and disease-relevant mechanisms of SG disassembly.

Accelerated Aging Analysis on Cycle Life of LiFePO4/Graphite Batteries Based on Different Rates

AbstractIn this study, different charge/discharge rates (1/3C, 1C, 1.5C, 1.8C, 2.0C and 2.5C) are used to accelerate the aging of commercial LiFePO4/graphite cells. The capacity attenuation mechanism is investigated by disassembling the aged full cells and analyzing the morphologies and chemical composition of electrode surfaces, the single electrode potentials, and so forth, when the capacity retention of full cell decays to 95 %, 90 %, 85 %, and 80 %. Through the tests, the capacity fade of the full cell is mainly ascribed to the irreversible loss of active lithium. However, when the test rate is not lower than 2.0C, the dominant mechanism for consumption of active lithium is changed to lithium deposition on the anode during the charging process instead of the generation of SEI film. As a consequence, the capacity decay rate at 2.0C or 2.5C is accelerated to a large degree. The capacity loss with cycling time is fitted by Arrhenius equations. The pre‐exponential factor at a given rate (Arate) increases linearly with the rising test rate when it is not more than 1.8C, and this corresponds to the results of disassembly analysis. Therefore, an unknown Arate in a reasonable range can be extrapolated by the data of other Arate values at relatively high rates. In addition, the calculated Arate after 10 % capacity loss can be used to replace the fitted value by the whole aging data. This provides a rapid and practical approach to estimate the lifetime of the full cell.

Common effects of attractive and repulsive signaling: Further analysis of Mical-mediated F-actin disassembly and regulation by Abl

ABSTRACTTo change their size, shape, and connectivity, cells require actin and tubulin proteins to assemble together into long polymers – and numerous extracellular stimuli have now been identified that alter the assembly and organization of these cytoskeletal structures. Yet, there remains a lack of defined signaling pathways from the cell surface to the cytoskeleton for many of these extracellular signals, and so we still know little of how they exert their precise structural effects. These extracellular cues may be soluble or substrate-bound and have historically been classified into two independently acting and antagonistic groups: growth-promoting/attractants (inducing turning toward the source of the factor/positive chemotropism) or growth-preventing/repellents (turning away from the source of the factor/negative chemotropism). Paradoxically, our recent results directly link the action of growth factors/chemoattractants and their signaling pathways to the promotion of the disassembly of the F-actin cytoskeleton (a defined readout of repellents/repulsive signaling). Herein, we add to this by simply driving a constitutively active form of Mical, which strongly disassembles F-actin/remodels cells in vivo independent of repulsive cues – and find that loss of Abl, which mediates growth factor signaling in these cells, decreases Mical's F-actin disassembly/cellular remodeling effects. Thus, our results are consistent with a hypothesis that cues defined as positive effectors of movement (growth factors/chemoattractants) can at least in some contexts enhance the F-actin disassembly and remodeling activity of repellents.