Statistical analysis of eclipsing binaries with monotonic orbital-period variations: A-type W UMa contact systems

Abstract We perform a dimension reduction analysis for a coupled rate-dependent/rate-independent adhesive-contact model in the setting of visco-elastodynamic plates. We work with a weak solvability notion inspired by the theory of (purely) rate-independent processes, and accordingly term the related solutions “semistable energetic”. For semistable energetic solutions, the momentum balance holds in a variational sense, whereas the flow rule for the adhesion parameter is replaced by a semistability condition coupled with an energy-dissipation inequality. Prior to addressing the dimension reduction analysis, we show that semistable energetic solutions to the three-dimensional damped adhesive contact model converge, as the viscosity term tends to zero, to three-dimensional semistable energetic solutions for the undamped corresponding system. We then perform a dimension reduction analysis, both in the case of a vanishing viscosity tensor, and in the complementary setting in which the damping is assumed to go to infinity as the thickness of the plate tends to zero. In both regimes, the presence of adhesive contact yields a nontrivial coupling of the in-plane and out-of-plane contributions. In the vanishing-viscosity case, we additionally confine the analysis to the case in which also inertia is neglected: in the vanishing-thickness limit, we thus obtain purely rate-independent evolution for the adhesive contact phenomenon, still formulated in terms of the semistable energetic solution concept. In the second, undamped scenario, inertia is instead encompassed; thus the limiting evolution retains a mixed rate-dependent/rate-independent character, and is again given in terms of an energy-dissipation inequality and a semistability condition.

Abstract Electrically induced bearing damage (EIBD) is a growing concern in electric drivetrains, where electrical discharge currents generate localized pitting that accelerates wear and premature failure. While ionic liquids (ILs) have shown promise as lubricant additives due to their natural physical adsorption, strong capabilities of tribofilm formation, and high molecular tunability, their role in mitigating EIBD is little known. This gap is especially evident because lubricant viscosity and film thickness affect discharge behavior, and additive performance in these regimes has not been well explored. In this study, tribological tests were performed using a ball-on-disk pure rolling contact system under applied voltage on polyalphaolefin (PAO) oils of three viscosities (4, 10, and 150 cSt measured at 100°C), with and without the addition of a phosphonium-phosphate IL. Surface damage was analyzed using scanning electron microscopy (SEM) and stylus profilometry. Damage quantification was based on pit morphology analysis of SEM images. The results provide new insights into how oil viscosity governs the discharge behavior and how an IL additive could influence the pit formation. While viscosity seems to play a main role, an IL additive might potentially help reduce EIBD and deserves further study.

The high-speed railway contact system provides electricity to trains, and its stability and reliability directly impact train safety and performance. To avoid economic losses from excessive upkeep and shutdowns due to unclear predictions of the contact system’s remaining useful life(RUL), an error-improved bidirectional long and short-term memory network (BiLSTM) early warning model is proposed, which firstly predicts the RUL of the contact system of high-speed railroads, and then combines the residuals of the predicted value to realize the fault warning of the contact system. The normalized contact system data are input into the PSO-BiLSTM model, and the relative error is corrected by using extreme gradient boosting (XGBoost). The research confirms that the RMSE of this prediction model decreases to 11.6293, and the MAE decreases to 7.9643; then reorder the maintenance data with pole number as index, perform feature parameter fusion based on the prediction residuals from the previous step, and use the kernel density estimation (KDE) method to determine the warning threshold, The results showed that the early warning model was able to predict contact system failures up to 30 days in advance, providing timely maintenance plans to identify potential failures and risks.

The efficiency and safety of modern wheeled vehicles significantly depend on the reliable interaction between pneumatic tires and the supporting road or soil surface under varying load conditions. This interaction is governed by a complex combination of elastic, viscous and plastic deformation processes, occurring both in the tire structure and in the contact layer of the supporting surface. Accurate description of these processes requires the development and application of advanced rheological models capable of reproducing the nonlinear and time-dependent behavior of tire materials. The analytical and experimental methodologies for determining the rheological parameters of pneumatic tires, including stiffness, deformation modulus, viscous resistance and internal friction characteristics are proposed in the paper. The methods are based on the analysis of static and dynamic deformation behavior, as well as on the spatial distribution of contact stresses in the tire–road interface. The approach allows for capturing the influence of varying load levels and inflation pressure on the tire’s mechanical response. The obtained rheological parameters provide a foundation for constructing numerical models of the tire–road contact system, enabling accurate prediction of contact stresses, deformation patterns, and dynamic loading during vehicle operation. The proposed methodologies reduce experimental complexity and improve parameter accuracy, offering practical value for tire design, optimization of vehicle dynamics and transport engineering applications.

Purpose: This paper aims to create an efficient system for protecting the overhead contact system of urban land electric transport from low short-circuit currents, which primarily occur at track intersections and from violations of rolling stock operation protocols. Despite existing protection measures, such incidents frequently result in severe consequences, including the total collapse of network segments and disruptions to passenger services. Methods: An analysis of existing feeder protection systems, identification of shortcomings within the existing protection framework, and the development of a new algorithm to detect low-power short circuits. Results: The obtained preliminary findings from experimental operations indicate the prospects for further research into low short-circuit currents. The introduction of rapid alarm registration systems facilitates the effective detection and elimination of threats associated with low short-circuit currents. Further tests are planned for the coming years, with the ultimate goal of fully automating the detection and prevention of emergency situations in the contact network associated with low short-circuit currents. Practical significance: The practical significance of this research lies in its potential to significantly boost the reliability of power supply for urban transportation networks, reduce unexpected downtime of public transport, and minimize passenger safety risks. The results of the study have the potential for widespread adoption in the operational practices of urban electric transport enterprises. This would ensure uninterrupted operation of infrastructure and enhance the overall quality of public services.

Abstract The replacement of insulators for overhead contact systems is currently mainly carried out through a combination of machine detection and manual judgment, lacking quantitative analysis of the extent of defect. In order to achieve quantitative analysis of the extent of insulator defect. this paper proposes a YOLOv8-ORSDCV algorithm. The proposed algorithm employs Oriented Bounding Box (OBB) to effectively address the tilting of the detection object caused by variations in shooting angles; To solve the problem of missing key information in nighttime insulator detection due to extremely insufficient background light, the algorithm introduces the Content-aware Reassembly of FEature (CARAFE) module, the detection accuracy of the model for targets is effectively improved; To enhance the feature extraction ability of the model for insulators and their defects details, the Feature Pyramid Shared Conv(FPSC) module and C2f_Diverse Branch Block (C2f_DBB) module are constructed to improve the model's understanding and analysis ability of image content, as well as detection speed.Finally, the OpenCV module was introduced to achieve precise quantification of the defect contour area through filtering, edge detection, and contour extraction. The research results show that, compared to the YOLOv8n algorithm, the four performance indicators (mAP@0.5, mAP@0.5-0.95, insulator detection accuracy, and insulator defect detection accuracy) of YOLOv8-ORSDCV algorithm have been improved by 2.3%, 11.1%, 1.6%, and 3%, respectively. In quantitative detection, the YOLOv8-ORSDCV algorithm achieves an insulation error of approximately 4.43% and a defect error of about 1.5%. On the basis of accurately locating the location of insulator defect, real-time quantitative display of the defect area has been achieved. The research results of this paper provide technical support for the intelligent monitoring and maintenance of high-speed railway OCS.

High-molecular-weight kininogen (HK) is known to bind lipopolysaccharides (LPS) with high affinity and serves as a crucial LPS carrier in circulation, supporting endotoxemia. However, its role in host defense against Gram-negative bacterial infection remains unclear. Here we demonstrate that HK directly binds to Escherichia coli (E. coli) via LPS and rapidly localizes to sites of infection. HK-deficient mice (Kng1–/–) showed increased susceptibility to infection, with increased bacterial dissemination, lung injury, and proinflammatory cytokine production. In contrast, endogenous expression of human HK in Kng1–/– mice restored survival, limited bacterial spread, and reduced tissue damage. Mechanistically, HK promoted neutrophil antimicrobial responses by enhancing reactive oxygen species production and microbicidal activity. Consistently, liver-specific HK deficiency recapitulated the impaired bacterial clearance and reduced survival upon E. coli challenge, highlighting the importance of plasma HK. Together, these findings identify HK as a new soluble pattern recognition molecule that senses E. coli invasion and initiates neutrophil-mediated antimicrobial responses, revealing a previously unrecognized protective function of the contact system in innate immunity.

Cow-Calf Contact Systems – How Can the Accidental Crushing of Calves Be Prevented after Calving?

Inositol hexakisphosphate kinase 1 (IP6K1)-driven tumor polyphosphate may contribute to immune checkpoint inhibitor-associated thrombosis

C1-INH and atiii inhibit vaso-occlusion and vascular inflammation in sickle cell disease mice

An antibody targeting high-molecular-weight kininogen blocks contact system activation in a model of polymicrobial sepsis.

Measurement of cleaved high-molecular-weight kininogen in patients with hereditary angioedema due to C1-inhibitor deficiency: preanalytical and analytical optimization.

Seismic vulnerability assessment method of overhead contact systems based on numerical simulation

Simulation is an essential methodology for analyzing the dynamic interactions between flexible overhead contact systems (FOCS) and pantographs. However, the computational efficiency of long-distance FOCS modelling is hindered by the large stiffness matrices, which significantly increase computational costs. To address this challenge, the study employs a coupled window approach to replace the entire FOCS model, considering key factors such as overlap segments and dual-pantograph operation. The proposed method is validated through comparisons with classical approaches and international standards. The results indicate that the proposed method significantly improves the computational efficiency of dynamic simulations, effectively addressing the issue of memory overflow caused by excessively large matrices. Furthermore, it can be effectively applied to various types of flexible overhead contact systems.

Growth and metabolism of calves in a dairy cow-calf contact system with gradual weaning and separation.

A coupled approach and analysis to pantograph-rigid catenary system considering the contact pair wear and system dynamic interaction

A class of time-dependent variational inequalities and their application in multi-layer contact systems

Introduction to a review series on the structural underpinnings of hemostatic plugs and thrombotic occlusions.

Abstract This study presents a numerical and analytical investigation of temperature distribution in the sliding contact of a pin on a disk structure, a phenomenon with various applications in industries such as automotive, aerospace, and industrial machinery. The research begins with an introduction to tribology, focusing on wear, friction, and sliding interactions, followed by the formulation of governing heat transfer and fluid dynamics equations to describe thermal behavior in contact regions. The influence of parameters such as speed, pressure, and material properties on temperature distribution is analyzed. Finite element analysis using Abaqus is employed to simulate the system, with results validated in confirmation of analytical solutions. Derived thermal behavior equations provide a foundation for designing and optimizing tribological systems. This work offers a comprehensive framework for understanding and improving the performance of sliding contact systems.