Mechanical Stress Conditions Research Articles

Investigation of pitting corrosion of 304L stainless steel in algerian manufacturing

Stainless steel structures are subjected to gradual deterioration of their fundamental qualities when subjected to both mechanical stress and harsh conditions. The objective of this work is to examine the influence of tension-induced cold deformation on the localized roughness corrosion of 304L steel in a 3% NaCl solution, which mimics the conditions of saltwater. The samples underwent corrosion testing using standardized and deformed tensile specimens of algerian industrial manufacturing at different deformation rates: 2.18%, 3.63%, 10.90%, and 16.36%. The results, which encompassed corrosion susceptibility, pitting tendencies, and repassivation potentials, were compared and examined in relation to the deformation rate. The findings suggest that when the deformation rates increase, all of these potentials decrease, except for the roughness potential, which shows a considerable decrease. This decline indicates a reduction in the material's ability to resist corrosion. The main reasons why stainless-steel samples exposed to the phenomenon of corroded pits fail in Algerian industrial manufacturing are directly related to their resistance and strength characteristics, which in turn affect the mechanical behavior of 304L steel and its electrochemical behavior in aggressive solutions.

Application of scalable sensor-assisted multi-scale computational methods in the simulation of micro mechanical behavior of composite materials

Micro mechanics involves the examination of the mechanical behavior of heterogeneous materials, taking into account inhomogeneities such as voids, fractures, and inclusions, and building on mathematical models developed. Composites bring engineering design barriers despite their strengths. Composite manufacturing and processing need specialized equipment, strategies, and labor, ensuring they are challenging and expensive. Mechanical behavior deals with how a composite material performs if faced with mechanical effects and action. Scalable sensor-assisted multi-scale computational Methods (SS-MSCM) are used to investigate topics ranging from the molecular basis of soot production in combustion to how molecule-level flaws influence macroscopic mechanical qualities. Carbon fiber reinforced polymers (CFRP) are generated by mixing graphene fiber with a resin, like vinyl ester and epoxy, to render a composite material with superior performance to the component ingredients. Hence, SS-MSCM-CFRP has Improved mechanical qualities achieved by incorporating nano-reinforcements, including carbon nanofibers and graphene nanoplates, into the CFRP matrix: enhanced flexural and compressive strengths, energy absorption upon impact, toughness to fracture, and interlaminar bonding. Composite materials feature excellent mechanical qualities like high strength and stiffness, fatigue resistance, and durability. It is possible to insert scalable sensors throughout the manufacturing process, which enables real-time monitoring of structural health, strain, and other factors. Scalable sensor-assisted multi-scale computational methods offer enhanced accuracy, real-time monitoring, and cost-effectiveness by integrating sensor data with computational models, improving predictions and failure mechanism insights. However, they face limitations like sensor dependency, computational complexity, data integration challenges, and high implementation costs, leading to potential discrepancies between simulation and experimental results. Important qualities include corrosion resistance, thermal conductivity, and electrical conductivity. As the composite materials develop to satisfy the established mechanical stress and temperature conditions, they offer high durability and strength.

Interplay between strain and charge in Cu(In,Ga)Se2 flexible photovoltaics

Flexible and lightweight Cu(In,Ga)Se2 (CIGS) thin-film solar cells are promising for versatile applications, but there is limited understanding of stress-induced changes. In this study, the charge carrier generation and trapping behavior under mechanical stress was investigated using flexible CIGS thin-film solar cells with various alkali treatments. Surface current at the CIGS surface decreased by convex bending, which occurs less with the incorporation of alkali metals. The formation energy of the carrier generating defects increased in convex bending environments clarifying the degradation of the surface current. Moreover, alkali-related defects had lower formation energy than the intrinsic acceptors, mitigating current degradation in mechanical stress condition. The altered defect energy levels were attributed to the deformation of the crystal structure under bending states. This study provides insights into the mitigating of strain-induced charge degradation for enhancing the performance and robustness of flexible CIGS photovoltaic devices.

Reproducing high mechanical load during industrial processing of ultra-high-temperature milk: Effect on frothing capacity

In this study, possible reasons for an increased level of free fatty acids (FFAs) in Ultra-High Temperature (UHT) treated full fat (3.5% wt/wt) milk and its effect on the frothing properties of milk were investigated. Lipolysis of raw milk from 2 different breeds of cattle (Holstein and Jersey) was induced by mechanical stress and kinetics of lipolysis were compared. Frothing capacity and foam stability of shelf stable milk with different concentrations of FFAs were determined, with a good to medium initial foam volume for up to 4 mEquiv FFA · (100 g fat)-1 fat and poor foam stability with >2 mEquiv FFA · (100 g fat)-1. A combination of mechanical stress and initial condition of fresh raw milk was found to trigger lipolysis and potential sources of mechanical stress during milk processing were identified.

Biocompatibility Evaluation of an Artificial Metallic Bone with Lattice Structure for Reconstruction of Bone Defect.

Mandibular reconstruction for large bone defects is performed with consideration of patients' specific morphology and sufficient strength. Metal additive manufacturing techniques have been used to develop biomaterials for mandibular reconstruction. Titanium artificial mandibles with a lattice structure have been proposed, and the optimal conditions for their strength to withstand mechanical stress around the mandible have been reported. This study investigated the biocompatibility of a titanium artificial bone with a lattice structure fabricated under optimal conditions. The samples were fabricated using metal additive manufacturing. Body diagonals with nodes (BDN) were selected as suitable lattice structures. Dode medium (DM) was selected for comparison. The samples were implanted into rabbit tibial defects and resected with the surrounding bone at two and four weeks. Specimens were evaluated radiographically, histologically, and histomorphometrically. Radiopacity in each lattice structure was observed at two and four weeks. Histological evaluation showed trabecular bone-like tissue inside the BDN compared to the DM at four weeks. No significant differences were noted in the bone volume inside the structures. This study demonstrated the in vivo compatibility of artificial metallic bones with a BDN structure under mechanical stress conditions.

Optogenetic induction of mechanical muscle stress identifies myosin regulatory ubiquitin ligase NHL-1 in C. elegans

Mechanical stress during muscle contraction is a constant threat to proteome integrity. However, there is a lack of experimental systems to identify critical proteostasis regulators under mechanical stress conditions. Here, we present the transgenic Caenorhabditis elegans model OptIMMuS (Optogenetic Induction of Mechanical Muscle Stress) to study changes in the proteostasis network associated with mechanical forces. Repeated blue light exposure of a muscle-expressed Chlamydomonas rheinhardii channelrhodopsin-2 variant results in sustained muscle contraction and mechanical stress. Using OptIMMuS, combined with proximity labeling and mass spectrometry, we identify regulators that cooperate with the myosin-directed chaperone UNC-45 in muscle proteostasis. One of these is the TRIM E3 ligase NHL-1, which interacts with UNC-45 and muscle myosin in genetic epistasis and co-immunoprecipitation experiments. We provide evidence that the ubiquitylation activity of NHL-1 regulates myosin levels and functionality under mechanical stress. In the future, OptIMMuS will help to identify muscle-specific proteostasis regulators of therapeutic relevance.

Enhancing Power Transformer Oil Quality Weight Factor using A Genetic Algorithm

Power transformers are critical to electrical power systems but are prone to failures due to factors such as heat, electricity, chemical reactions, mechanical stress, and adverse environmental conditions. Moni-toring the insulating oil effectively is key to preventing these failures. A major challenge in this process is determining the optimal weights for the oil quality index, which lacks a standardized benchmark and often relies on subjective expert assessments. To reduce expert bias and subjectivity, this research utilizes a genetic algorithm to optimize the weightings for five essential parameters: color, water content, break-down voltage (BDV), interfacial tension (IFT), and acidity. The algorithm operates through three stages: crossover, mutation, and selection, and analyzes data from 504 oil tests across various transformers. The mean absolute percentage error (MAPE) is used as the fitness value to assess the algorithm's effective-ness. The optimization process determined the best conditions as 132 iterations, a population size of 180, a crossover rate of 0.2, and a mutation rate of 0.8. These parameters achieved an average MAPE of 1.799% over ten trials, indicating high accuracy. This research not only optimizes the weighting of the oil quality index but also significantly reduces the need for expert input and subjective judgments in trans-former maintenance. The findings are expected to improve the efficiency and reliability of power trans-formers, thereby minimizing failures and associated economic costs.

Classical molecular dynamics simulation of atomic structure transitions in FeSiCuMgAl high-entropy alloys under biaxial stretching

Classical molecular dynamics (MD) simulations were utilized in this study to investigate the mechanical properties of the crystal structure of high-entropy alloys under various mechanical stress conditions. The stress-strain behaviors and the merging of the crystal structure growth of FeSiCuMgAl high-entropy alloys during biaxial tensile deformation were simulated. Three stages of atomic structure transformation were observed during biaxial stretching of FeSiCuMgAl high-entropy alloys at a strain rate of 1010 s−1. In the first stage, the structure transitioned from face-centered cubic (fcc) to body-centered cubic (bcc), hexagonal close-packed (hcp), and disordered structures. The second stage involved a transition from bcc, hcp, and disordered structures to fcc. The third and final stage involved a transition from fcc, bcc, and hcp to disordered structure. To gather more information about the simulation process, this research simulated MD by varying the strain rate of tensile deformation. At a strain rate as low as 0.5×109 s−1 and below, there was minimal involvement of the bcc phase in the tensile process. During the simulation work, co-neighborhood analysis, stress-strain analysis, and dislocation analysis were utilized to accurately describe the simulated tensile behavior. The simulation results will provide more insights into the design and preparation of high-entropy alloys as foundational materials.

The effect of elastic and plastic stresses on the electrical resistivity of conductive materials

The mobility sector has been responsible for large emissions of harmful greenhouse gases worldwide for years. E-mobility can contribute to a reduction of these emissions. For a faster spread and acceptance of electric vehicles, the achievable range and thus the efficiency of the individual components in the drive and charging train is essential. In addition to the battery and the electric machine, losses in the cables and bus bars are playing an increasingly important role. The cross-sectional shape, material and manufacturing technology of these conductive materials depends on the voltage and power to be transmitted and may still change in the future, especially in the field of fast charging and increased voltage.The aim of this work is to investigate the influence of the mechanical stress condition of copper, brass and aluminium materials on their electrical conductivity. The conductivity is measured by means of 4-wire measurements under defined tensile and compressive loads. The effects of elastic and plastic strains are taken into account. The findings can be used for an optimized manufacturing strategy for conductive components for future applications.

Impact of residual stress on coronary plaque stress/strain calculations using optical coherence tomography image-based multi-layer models.

Mechanical stress and strain conditions play an important role in atherosclerosis plaque progression, remodeling and potential rupture and may be used in plaque vulnerability assessment for better clinical diagnosis and treatment decisions. Single layer plaque models without residual stress have been widely used due to unavailability of multi-layer image segmentation method and residual stress data. However, vessel layered structure and residual stress have large impact on stress/strain calculations and should be included in the models. In this study, intravascular optical coherence tomography (OCT) data of coronary plaques from 10 patients were acquired and segmented to obtain the three-layer vessel structure using an in-house automatic segmentation algorithm. Multi- and single-layer 3D thin-slice biomechanical plaque models with and without residual stress were constructed to assess the impact of residual stress on stress/strain calculations. Our results showed that residual stress led to a more uniform stress distribution across the vessel wall, with considerable plaque stress/strain decrease on inner wall and increase on vessel out-wall. Multi-layer model with residual stress inclusion reduced inner wall maximum and mean plaque stresses by 38.57% and 59.70%, and increased out-wall maximum and mean plaque stresses by 572.84% and 432.03%. These findings demonstrated the importance of multi-layer modeling with residual stress for more accurate plaque stress/strain calculations, which will have great impact in plaque cap stress calculation and plaque rupture risk assessment. Further large-scale studies are needed to validate our findings.

Modulation of the Cellular Microenvironment by Mechanical Fluid Shear Stress and Hypoxia Alters the Differentiation Capacity of Skeletal Muscle-Derived Stem Cells

Skeletal muscle-derived stem cells (MDSCs) are the key modulators of muscle regeneration. An inappropriate cellular microenvironment can reduce the regenerative capacity of MDSCs. This study evaluates the effect of microenvironmental alterations on the cell differentiation capacity using either mechanical fluid shear stress (FSS) or hypoxic conditions. C2C12 mouse myoblasts were differentiated under cyclic FSS (CFSS), periodic FSS (PFSS) for one hour, and hypoxia (3% O2) for up to seven days. Cell proliferation and myogenic differentiation capacities were evaluated using cell viability assays, immunohistochemical staining, and morphometric analysis. The expression of MyoD, myogenin, myosin heavy chain, nitric oxide, hypoxia-inducible factor 1 alpha (HIF1α), vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) was quantified by means of RT-qPCR. The data showed that FSS conditions altered cell morphology and increased cell viability and cell distribution compared to static conditions. MyoD and myogenin expression was upregulated under both FSS conditions. CFSS induction improved myogenic differentiation parameters including myotube number, size and fusion capacity. Although hypoxia enhanced cell viability compared to normoxia, it reduced differentiation capacity, as indicated by the downregulation of myogenin and mTOR expression, as well as reducing myotube formation. Under hypoxic conditions, increased nitric oxide production and upregulation of VEGF expression were detected for up to 72 h. The data suggest an improved myogenic differentiation capacity under mechanical FSS; in contrast, the cell differentiation capacity was impaired under hypoxic conditions. The data point out that optimizing the biomechanical and oxidative stressors in the cellular microenvironment could improve stem cell transplantation and enhance their regenerative potential in the context of cell-based therapies.

Temperature-Dependent Mechanical Anisotropy in Textured Zircaloy Cladding

This work evaluates deformation activity in textured zircaloy-4 cladding with the aim of elucidating the mechanisms that govern mechanical behavior across a temperature range anticipated in reactor service. In particular, the dependence of mechanical anisotropy on temperature and stress state (ratio of applied stresses) is examined via uniaxial and biaxial tensile experiments at room temperature and 400 °C. The mechanical behavior is interpreted based on micro-texture and dominant slip system activity. Thermal activation of basal systems is found as a key mechanism affecting mechanical behavior across the temperature range. The biaxial stress states produce resolved shear stresses contrasting to uniaxial stress states. Mechanical testing and implications for reactor pellet-cladding mechanical interaction stress conditions are discussed.

Biomass carbon-reinforced zinc-based composite oxide as an anode for superior sodium storage

The pursuit of high-abundance, cost-effective sodium-ion batteries represents a longstanding and valuable objective in the field. However, significant challenges remain in the quest for breakthroughs, particularly in the discovery of high-performance anode materials and a deeper understanding of the sodium storage mechanism. In this study, we present novel insights into the sodium storage properties of biomass carbon-reinforced Zn2P2O7 (Zn2P2O7/C-c) synthesized via a hydrothermal method followed by annealing, marking the first report of its kind. The unique loose porous structure of the Zn2P2O7/C-c composite offers multiple advantages. It facilitates efficient electrolyte infiltration, enhances the diffusion pathways for sodium ions, expedites electron transfer, and crucially, promotes the retention of Zn2P2O7 on the carbon substrate, even under conditions of mechanical stress or pulverization. Consequently, the Zn2P2O7/C-c composite demonstrates significantly improved rate capability, exhibiting specific capacities of 276.11, 234.41, 195.28, and 149.56 mA h g−1 at current densities of 0.2, 0.5, 1, and 2 A g−1, respectively. Furthermore, it exhibits exceptional cyclic stability with a capacity retention rate of 71% after 1000 charge-discharge cycles at 1 A g−1. In-depth in-situ/ex-situ characterization techniques confirm that the sodium storage mechanism involves a conversion reaction between Zn2P2O7 and Zn, as well as an alloying reaction between Zn and ZnNa13. Kinetic analysis underscores the predominant role of pseudocapacitance in facilitating sodium storage, particularly at high charge-discharge rates. These findings offer valuable insights and inspiration for the exploration of high-performance Zn2P2O7-based anode materials for sodium-ion batteries, representing a significant step toward the realization of cost-effective and efficient sodium-ion battery technology in the future.

High-performance solid-state Li-ion batteries enabled by homogeneous, large-area ferroelectric PVDF-TrFE solid polymer electrolytes via horizontal centrifugal casting method

Solid polymer electrolytes (SPEs) have emerged as promising alternatives for enhancing the safety features of lithium-ion batteries (LIBs) while remaining compatible with established LIB manufacturing processes. However, a persistent challenge has been the relatively limited yield achieved via traditional fabrication techniques such as solution casting and doctor blade methods. In this study, we present a novel strategy to produce extensive and uniform films of solid polymer electrolytes using a ferroelectric polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) polymer. This approach employs horizontal centrifugal casting (HCC), a technique hitherto unutilized for SPE production. The substantial centrifugal forces generated during the HCC process yield SPE films characterized by uniform thickness across the surface and elevated ionic conductivity at ambient temperature. Compared to conventional solution casting techniques, the Li//Li cell featuring the SPE derived from HCC manifests stable electrochemical performance and increased cycle endurance. Additionally, a full cell incorporating a Li iron phosphate cathode displays consistent electrochemical behavior at room temperature. Notably, a 3 × 4 cm2 pouch cell maintains its performance attributes even under mechanical stress conditions such as folding and punching. These findings underscore the potential effectiveness of employing the HCC method in the development of high-performance SPE-based LIB systems.

Abstract B061: Development of a pancreatic ductal adenocarcinoma 3D tumor model for high-throughput drug screening

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a persistent malignancy that is difficult to diagnose in its early stage and is one of the leading cancer-related deaths worldwide. Currently, limited therapeutic options are available for PDAC, resulting in an extremely low 5-year survival rate. To speed up the discovery of novel therapeutics, a reliable 3D model that highly simulates the PDAC tumor microenvironment is needed for large-scale drug screening. In this study, we propose a novel 3D model for restoring the PDAC tumor microenvironment by targeting cancer-associated fibroblasts (CAFs), which serve as the key component of the PDAC, providing its heterogeneity and contributing to reciprocal signaling and drug resistance. Our previous studies have demonstrated that Adipose-derived mesenchymal stem cells can differentiate into varying subtypes CAFs when co-cultured with PDAC cells both in vitro and in vivo. Following this strategy, we utilize the fibroblast-populated collagen lattice (FPCL) modeling approach, which relies on the contractility of fibroblasts in a collagen gel matrix, to provide the mechanical stress and hypoxic conditions for the 3D tumor models. Human Adipose-derived mesenchymal stem cells as CAF precursors and PDAC cell lines were mixed with collagen solution to make the collagen discs, resulting in the formation of 3D PDAC tumor models within a week. The morphological analyses, along with global transcriptome and metabolomic analyses, were performed to confirm the clinical-like mature ductal glands of PDAC cells and CAFs-like spindle-shaped of mesenchymal stem cells in the interior of PDAC-FPCL (PDAC-F). Moreover, the PDAC-F has shown a high tumorigenic potential in vivo animal model. Additionally, PDAC-F was shown to allow combination therapies screening of anticancer and antifibrotic drugs in the drug screening test, demonstrating that the combination therapeutics have better efficacy. In conclusion, our PDAC-F is built with distinct features of PDAC, reproducing the heterogeneous and high stiffness with a clinical-like PDAC morphology. In addition, the short modeling time and the high reproducibility of this PDAC-F open the possibilities for large-scale drug screening, which is expected to accelerate new drug development and provide effective treatment for pancreatic cancer patients. Citation Format: Xiaoyu Song, Yuma Nihashi, Yasuyuki S. Kida. Development of a pancreatic ductal adenocarcinoma 3D tumor model for high-throughput drug screening [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B061.

Nanoscale dynamical investigation of the hemoglobin complex with the bacterial protein IsdB: is their interaction stabilized by catch bonds?

Iron-regulated surface determinant B (IsdB) is a surface protein of Staphylococcus aureus that plays essential roles in host cell invasion by mediating both bacterial adhesion and hemic iron acquisition. Single-molecule experiments have recently revealed that the binding of IsdB to vitronectin and integrins is dramatically strengthened under mechanical stress conditions, promoting staphylococcal adhesion. Here we conducted atomic force spectroscopy (AFS) measurements of the interaction between IsdB and hemoglobin (Hb), in both its oxidized (metHb) and reduced forms (HbCO). While the former represents the natural substrate for IsdB, the latter is resistant to heme extraction. For the unbinding between IsdB and HbCO, we obtained a linear trend in the Bell-Evans plot, indicative of a weakening of the interaction upon mechanical stress. For the unbinding between IsdB and metHb, we found similar behavior at low loading rates. Remarkably, a non-linear trend of the complex interaction force was detected at higher force-pulling rates. Such behavior may provide some cues to the ability of IsdB to form stress-dependent bonds also with Hb, possibly enabling a more efficient heme transfer through stabilization of the transient (in vivo) IsdB-Hb complex.

FEATURES OF THE INITIAL DEFORMED STATE OF PYROPEZOELECTRICS OF TRIGONAL SYSTEM

A model of a prestressed thermoelectroelastic medium under conditions of initial mechanical stress, electrostatic field and temperature is proposed. Within the framework of the coupled theory of thermoelectroelasticity, linearized constitutive relations and equations of motion of a prestressed thermoelectroelastic medium are constructed. It is assumed that the initial deformed state induced in the material is homogeneous, the initial temperature does not exceed the temperature of phase transitions, and the initial electrostatic field is specified by the electric field strength vector. Within the framework of the assumptions made, a three-dimensional formulation of dynamic problems for prestressed semi-bounded media made of the materials under consideration is given. Using operational calculus methods, the problem is reduced to a system of ordinary differential equations, the solution of which is presented in matrix form and allows one to analyze the influence of external factors of various natures on the dynamics of a prestressed thermoelectroelastic medium. Particular attention is paid to a detailed study of the initial deformed state of the material under conditions of separate and combined exposure to mechanical stress, electrostatic field and temperature. The presence of piezo- and pyro-effects, characteristic of the class of pyroelectrics under consideration, is shown: the appearance of electrical induction under the action of mechanical stresses along the axes, and the appearance of electrical induction under thermal influence in the absence of mechanical stresses. The types of mechanical influences leading to maximum values of electrical induction have been established. It is shown that under combined temperature and mechanical influences, mechanical stresses play a decisive role in the nature of the induced deformations. The presence of an initial temperature can either weaken or strengthen the influence of the electrostatic field. With a combined mechanical and electrostatic effect, the presence of an initial electrostatic field of high intensity, depending on its direction, leads to qualitative changes in the nature of the stress-strain state. The research results are presented in dimensionless parameters, presented in the form of graphs and may be of particular interest in the development, design and optimization of pyropiezoelectric materials used in the creation of new micro- and nano-sized devices and devices for general purposes.

4-Hydroxybenzenesulfonic acid triggers rapid preparation of phenolic aerogel composites by ambient pressure drying

Phenolic aerogel composites, as an excellent thermal insulation material, have been used in aerospace to resist extreme working conditions of severe heating and intense mechanical stress. However, the high cost and lengthy preparation process seriously restricts their more extensive application. Herein, a novel strategy for rapid preparation of aerogel composites by ambient pressure drying is enabled by copolymerization with 4-hydroxybenzenesulfonic acid. That is, the reactive 4-hydroxybenzenesulfonic acid can serve as the acid catalyst to accelerate both the protonation step and the gelation step during the preparation process of phenolic aerogel. After copolymerization with 4-hydroxybenzenesulfonic acid, these sulfonic acid groups significantly accelerate the protonation of benzoxazine intermediates, leading to more carbocation formation. The activation energy of curing reaction is significant decreased from 300 kJ∙mol−1 to 90 kJ∙mol−1. Thus, 4-hydroxybenzenesulfonic acid containing phenol formaldehyde resin (PFS) aerogel precursors exhibit much faster gelation reaction (within 4 h) than phenol formaldehyde resin (PF) aerogel precursor (12 h), which further facilitates the preparation of phenolic aerogel composites with needled quartz fiber felt by ambient pressure drying. Importantly, the PFS aerogel composites exhibit excellent thermal insulation performance under low heat flux and good fire safety under high heat flux. Rapid gelation of PFS triggered by 4-hydroxybenzenesulfonic acid provides a new approach to develop phenolic aerogel composites with low energy consumption, low cost and short preparation cycle.

The effect of static stresses on the acceleration of the decomposition processes in the ferritic-martensitic steels in conditions of neutron irradiation to a dose of 85 dpa

Behavior of the corrosion-resistant EP823 steel (Fe-11Cr-Mn-Mo-Nb-V-W-Ni-Si-0.17C) and its ODS modification, hardened by yttrium, yttrium-titanium oxides (EP823-ODS) in conditions of static mechanical stress under high dose exposure in a fast-neutron reactor was studied using Mössbauer spectroscopy and electron microscopy. Mechanical stresses were revealed to result in a deformation of the fuel elements walls and the acceleration of the decomposition processes in steel structure with a release of chromium into the intermetallic χ phase and to the Me23C6 carbide formation. It was also shown that the key factor accelerating the structure decomposition upon neutron irradiation to a dose of 85 dpa at 505 °C is anisotropy of stresses between longitudinal and transverse directions of fuel cladding tube surface.

Research on internal short circuit detection method for lithium-ion batteries based on battery expansion characteristics

Short circuits are a major contributor to thermal runaway in lithium-ion batteries, but present detection techniques cannot distinguish different forms of short circuits. Therefore, the paper provides a detection method for internal short circuits (ISCs) based on coupled mechanical stress that can determine the type of short circuit. Firstly, cathode-anode (Ca-An) short-circuit batteries with a controllable triggering time and measurable internal temperature and electrode potential are designed. Secondly, the performance evolution of fault batteries under coupled mechanical stress conditions is investigated, along with the impact of faults on the battery's safety performance. Additionally, the influence of battery expansion characteristics on the contact pressure at the short circuit location and the correlation between short circuit resistance and mechanical stress are analyzed. The results show, except for self-discharge, no significant differences between Ca-An short-circuit and normal batteries, and there are no mutable features observed, but the faults can exacerbate internal-external temperature differences during charging. The different reasons for thermal runaway during sustained pressurization between short-circuit and normal batteries are revealed. Finally, a method for detecting ISC based on the differences in short-circuit resistance at different states of charge is proposed. Overall, the paper provides a basis for fault classification in lithium-ion batteries.