Search Results (1,597)

The influence of standardized driving-cycle characteristics on the dynamic and energy performance of a parallel hybrid electric vehicle controlled by a fixed-gain PID speed controller was investigated. A control-oriented MATLAB/Simulink model was developed, including an electric traction subsystem, an electric battery pack, a simplified internal combustion engine subsystem, a supervisory torque-split controller and longitudinal vehicle dynamics. The same controller configuration was evaluated under the FTP75, HWFET and US06 cycles, with the shorter cycles repeated to obtain comparable durations. Control quality was assessed using RMSE, MAE, IAE and ITAE, whereas energy performance was quantified using battery state-of-charge variation, fuel consumption, engine utilization and traction motor current loading. FTP75 yielded favorable performance, with RMSE = 0.265 m/s, fuel consumption of 4.824 L/100 km and an SoC decrease of 19.698%, whereas US06 proved severe, with RMSE = 4.567 m/s, fuel consumption of 10.328 L/100 km, an SoC decrease of 41.630% and a peak motor current of 580.9 A. Sensitivity analysis showed that ±20% PID-gain variations do not materially alter the principal conclusion, while supervisory energy-management parameters exert a stronger influence on the trade-off between tracking quality, fuel expenditure and charge maintenance. The results confirm that fixed-gain PID control is cycle-dependent and becomes inadequate under aggressive driving conditions. Full article

This systematic review investigates the application of computer-vision technologies for automated monitoring of personal protective equipment compliance in industrial environments. This review followed the PRISMA 2020 guidelines and covered studies published between 2010 and 24 February 2026. It provides a structured synthesis of advances in deep learning-based object detection models, with particular emphasis on different YOLO variants, two-stage detectors such as Faster R-CNN, and emerging transformer-based and vision–language models. Model effectiveness, reported performance metrics, and dataset characteristics are comparatively examined, including their performance under practical operating conditions. Special attention is given to performance variability in real-world scenarios affected by illumination changes, occlusion, viewing angle variation, worker movement, computational constraints, and large-scale deployment requirements. The review also appraises the reporting quality and risk of bias of the included studies and identifies current research trends, methodological limitations, and the gap between laboratory validation and industrial implementation. It also outlines future directions for improving the reliability, cost-effectiveness, and practical application of computer vision-based personal protective equipment compliance systems. Full article

This paper presents a new process for forming stepped shafts by upsetting with two movable deformation zones. The developed technology enables several shaft steps to be formed at the same time, thereby increasing process efficiency and reducing material consumption. A distinctive feature of the process is that it uses two forming sleeves, each with a variable cross-section of the impression, which move in an opposite direction to that of the punches during operation. This results in a simultaneous occurrence of upsetting and extrusion, thus leading to intensified plastic deformation and stabilized metal flow. The practical applicability of the process is demonstrated on the example of a forged railway axle. An analysis is carried out by the finite element method (FEM) using specimens of hot-formed C35 steel. The obtained results reveal proper material flow and the correct filling of the tool impressions. The examination of strain and stress distributions confirms favorable forming conditions. The calculated values of the Cockcroft–Latham integral indicate favorable forming conditions and a low risk of fracture initiation during the analyzed process. The results demonstrate the potential of the proposed technology and provide a basis for future experimental verification and industrial assessment. Full article

This study presents a comprehensive computational evaluation of radiofrequency (RF) ablation efficacy and the spatial formation of thermal ablation zones within a 3D model of a liver tumor. By systematically comparing these configurations, the study aims to elucidate the physical mechanisms governing electromagnetic (EM) energy dissipation in hepatic tissue and to provide clear engineering guidelines for optimizing RF applicator selection and treatment planning in clinical practice. To reliably simulate the biophysical phenomena of the RF ablation procedure, a coupled electro-thermal model based on the finite element method and the Pennes bioheat equation was implemented. The research investigates six distinct applicator variants: conventional needle-type applicators and advanced expandable umbrella-type RF applicators equipped with four- and eight-tine electrodes, each evaluated in both monopolar and bipolar configurations. Numerical simulations were conducted for a standard 10 min ablation procedure at varying applied voltages to assess the specific absorption rate (SAR) distribution, transient heating dynamics, and the exact volumes of the resulting coagulation necrosis which were quantified using rigorous isotherms and the cumulative equivalent minutes at 43 °C (CEM₄₃) thermal dose index. Volumetric analysis of the ablation zones revealed that bipolar multi-tine electrodes induce highly localized heat concentration. Conversely, monopolar multi-tine setups strongly disperse EM energy. The results demonstrated that, for conventional needle applicators, the monopolar configuration generated significantly larger necrosis zones than the bipolar operating mode. The RF applicator geometry and its operating mode directly dictate the spatial extent of liver tissue necrosis. Moreover, advanced numerical treatment planning is essential for optimizing SAR and CEM₄₃ distributions and ensuring safe and complete hepatocellular carcinoma eradication. Full article

The transition towards a circular economy in architecture requires new methods for reusing construction and demolition waste as a material resource. Recycled aggregates are a promising alternative to natural aggregates, although their variable porosity and particle grading often limit practical application. This study evaluates the suitability of recycled concrete aggregate (RCA) and recycled ceramic aggregate for small-scale architectural elements such as street furniture. Three comparative mixtures were analysed using particle size distribution data, the Modified Andreasen model, and the EMMA (Elkem Materials Mix Analyzer) tool. Two mixtures contained recycled aggregates, while one reference mixture was based on natural aggregates. The assessment focused on particle packing, water demand, and binder content. The recycled concrete aggregate mixture showed results closest to the reference mix, with water content of 180 kg/m³ and a water-to-cement ratio of 0.50, compared with 170 kg/m³ and 0.50 for the natural aggregate mixture. The ceramic aggregate mixture required the highest water content (200 kg/m³) and cement dosage (380 kg/m³) due to its higher porosity (15–18%) and finer particle fraction. By adjusting aggregate proportions within the packing model, satisfactory particle structuring was still achieved in all mixtures (q = 0.31–0.35). The study shows that particle packing methods, commonly used in concrete technology, can also support early-stage architectural material selection. Recycled aggregates, particularly RCA, may therefore be considered a viable substitute for natural materials in benches, seating panels, and other small-scale circular design applications. Full article

Automotive roof racks are important lightweight accessories for vehicles, and their extrusion performance is affected by the coupled effects of material hot deformation behavior, die flow resistance and billet surface layer transport. In this study, Al-0.9Mg-0.6Si alloy samples were subjected to hot compression tests at 350–500 °C and strain rates of 0.01–10 s⁻¹. The corrected true stress–true strain data were used to establish and validate an Arrhenius-type constitutive model, which was then implemented in HyperXtrude to simulate the hot extrusion of an automotive roof rack profile. The hot working map showed that the main rheological instability region was located at high strain rates, and the preferred processing window was 437–500 °C and 0.01–0.6 s⁻¹. EBSD analysis showed that hot compression refined the microstructure relative to the initial average grain size of 173.147 μm, and the most uniform grain size distribution was obtained at 500 °C and 0.1 s⁻¹. The ODF results indicated strengthened {111}<121> and <110>//TD texture components after compression. The finite-element results showed that the standard deviation of outlet velocity (SDV), used here as an index of outlet flow uniformity, increased with ram speed, billet preheating temperature and die preheating temperature, but decreased with increasing container temperature. Finally, grain size and texture measurements from butt discard samples were compared with simulated surface layer flow paths, supporting the predicted difference between simple axial flow and complex recirculating flow near the die. Full article

The European 2035 decarbonisation framework rests on a conditional premise—that higher renewable-electricity penetration accelerates battery electric vehicle (BEV) adoption—yet it has not been tested at the panel level. The question is timely: the December 2025 Automotive Package would soften the 2035 target from 100 to 90 percent CO₂ reduction and permit continued production of plug-in hybrids beyond 2035, while the Alternative Fuels Infrastructure Regulation (AFIR) imposes binding charging-coverage targets from 2025 onwards. We assemble an annual panel of 31 European economies over 2015–2024 (310 country-year observations) and combine a two-way fixed-effects baseline on five disaggregated powertrain shares, an interaction model with public charging coverage as a moderator, and a Hansen-style threshold panel. The within-country BEV-share coefficient on renewable-electricity penetration is statistically null (β = +0.18, p = 0.247), rejecting the linear premise. The plug-in hybrid share, by contrast, responds positively and unconditionally (β = +0.36, p = 0.001)—a “PHEV paradox” of compositional response. The BEV channel, by contrast, is conditional on infrastructure: its marginal effect rises with public charging coverage and is positive only in the upper part of the charging distribution (interaction β₃ = +0.13, p = 0.027). A formal Hansen-style threshold test in the renewable share does not reject the linear specification (sup-F = 0.73, bootstrap p = 0.97), so the BEV conditionality is identified through the charging-coverage interaction. The findings characterise a two-speed European transition. The first channel reflects compliance-led PHEV hedging; the second reflects BEV charging network complementarity enabled by AFIR-mandated coverage. Subsidy rebalancing away from PHEV eligibility, strict AFIR enforcement, and PHEV utility-factor reform are necessary policy levers for the 2035 framework to deliver full electrification rather than the partial electrification that current incentives yield. Full article

The multilingualism found in many countries, as well as within professional groups, complicates verbal communication, as both communicating parties are required to know all the languages used. This problem is exacerbated by the fact that languages are often mixed during communication. Avatars can be used to communicate with deaf people by simulating the behavior of sign language users. This paper presents a digital sign language avatar built on a language-agnostic, multimodal animation pipeline that decouples linguistic input from animation, combining skeletal body and hand motion with facial blendshape animation as independent modalities. It also presents a methodology for assessing its quality with the participation of experts (i.e., professional sign language interpreters) and the corresponding research results. The average quality rating of the avatar interface by the experts was 5.5 on a 7-point Likert scale, indicating its potential for practical use. At the same time, the research identified opportunities to improve the naturalness of movement and the consistency of gesture transitions. Full article

Producers of aggregates must prove that their products meet required standards. Effective decision-making in crushing processes requires analyzing how crusher operation affects component wear, particularly crushing plates. Their deterioration alters the crusher’s geometry, increasing the closed side setting (CSS) and influencing the final product’s granulation. Monitoring these changes is difficult but essential for ensuring product quality. This study presents a measurement system designed to assess wear in jaw crusher plates and its impact on the crushed material. Since aggregates and crushers vary widely, operational parameters such as wear rate, power consumption, and crushing force also differ, affecting product composition. Therefore, reliable measurement methods are crucial for accurate process evaluation and decision-making. In the analysis of the results, the Lorentzian distribution was used as a flexible tool to mathematically describe changes in the particle size distribution of the ground product. The proposed approach combines granulometric analysis of the crushed product with a Lorentzian model to predict crushing performance. Laboratory experiments confirmed the method’s effectiveness, demonstrating its ability to monitor plate wear and predict resulting product characteristics. In particular, it was observed that a relatively small increase in the CSS (approximately 9.23%) did not result in significant changes in the particle size distribution, indicating the presence of a “non-sensitive” operating range. The results show that systematic wear assessment can improve control over crushing operations and enhance product quality verification. Full article

Radium and barium are hazardous contaminants that frequently occur in wastewater, posing significant risks to human health and the environment. This study provides a comparative evaluation of five synthetic zeolites—3A, 4A, 5A, 13X (commercial), and NaP1 (synthesized from fly ash)—representing three distinct framework types (LTA, FAU, and GIS) for the removal of radium from real saline mine water (Upper Silesia Coal Basin, Poland) and barium from synthetic water. The zeolites were characterized by XRD, SEM-EDS, and N₂ adsorption, and tested in both granular and fine-powder forms using sequential batch adsorption experiments. For radium removal from mine water, zeolite NaP1 demonstrated superior performance, maintaining low ²²⁶Ra effluent activity (<1 Bq/L), even after treating ~50 L of water. Zeolites 3A, 4A, 5A, and 13X exhibited significantly lower performance than NaP1, showing poor selectivity for radium. In the barium batch tests, all tested zeolites achieved removal efficiencies exceeding 95% at low initial concentrations (100 mg/L). At higher concentrations (2000 mg/L), zeolites 3A, 4A, and 13X exhibited the highest adsorption capacities, with zeolite 4A achieving the maximum value of approximately 239.9 mg/g. The experiments demonstrated that idealized laboratory conditions can substantially overestimate sorbent performance relative to real water systems. Full article

This study proposes a new method for rolling steel balls using spiral discs. The aim of the study was to investigate whether the proposed method could be used to produce balls with a diameter of 63 mm, as well as to determine the effect of tool geometry and the number of billets on process stability, force, and the energy parameters of the rolling process. Numerical simulations were performed using Forge^® NxT v.4.0. The billet for rolling was made of C60 steel and preheated to 1050 °C. The following cases of ball rolling were simulated: Ball rolling using flat discs with single, double, and triple spiral impressions made on their working surface, and ball rolling using tapered discs for two different configurations of the working system. The rolling process was examined in terms of ball shape, internal defect formation, temperature distribution, as well as force and energy parameters. The results showed that the rolling process conducted using tapered discs and by flat discs with single and double impressions produced correctly shaped balls without internal cracks. It was also found that discs with double impressions were more advantageous than the single-impression ones in terms of energy consumption, while the use of discs with triple spiral impressions led to higher tool load and reduced product quality despite the high efficiency of these discs. The system comprising one disc with an external conical working surface and one disc with an internal conical working surface yielded the best results with the lowest energy consumption and power demand. The findings of this study demonstrate that ball rolling using spiral discs is a promising alternative to standard skew rolling methods. Full article

The paper presents a fast adaptive power control with implicit predictive behavior for an on-board power converter operating in support of a 400 Hz aircraft electrical network. Accurate control of active and reactive power in such high-frequency networks requires precise estimation of the network voltage phase, frequency, and amplitude. Therefore, a proposed adaptive phase-locked loop (PLL) algorithm is integrated with a proportional resonant current controller (PR). The adaptive PLL continuously estimates the instantaneous phase, frequency, and amplitude of the fundamental voltage component, enabling fast synchronization and dynamic adjustment of the PR controller resonant frequency. Consequently, the combination familiarises anticipatory response characteristics with the control loop without the need for computationally intensive model predictive control algorithms. The simulation results demonstrate that the proposed method significantly reduces the synchronization time, maintains high accuracy under frequency variations and harmonic distortion, and exhibits robustness against measurement noise. Furthermore, the modular and computationally efficient structure of the algorithm makes it suitable for real-time implementation of FPGA. The proposed approach provides an effective solution for high-performance power management in aircraft electrical systems, ensuring precise power control under hard dynamic conditions. Full article

This paper presents the results of the preparation and electrical characterization of Ru–Si–O thin-film nanocomposites deposited by magnetron sputtering (pDC) with varying oxygen content ranging from 0% to 50%. Measurements were conducted over a wide frequency range of 50 Hz–5 MHz and temperatures of 20–373 K. Conductivity analysis revealed that DC conduction occurs at low frequencies (≤10³ Hz), while an increase in conductivity associated with electron tunneling mechanisms is observed at higher frequencies. The determined charge transport activation energies range from 3 × 10⁻⁴ eV for the oxygen-free sample to 6 × 10⁻² eV for the high-oxygen samples, indicating a significant effect of composition on the conduction mechanisms. In samples containing 30% and 50% oxygen, two characteristic frequency ranges for the activation of transport processes were observed (e.g., ~10²–10³ Hz and 10⁴–10⁶ Hz), suggesting the coexistence of multiple tunneling mechanisms. Phase angle analysis revealed a transition from values near –90° at 151 K to values near 0° at 333 K, characteristic of parallel RC systems. The minimum dielectric loss tangent occurs in the range of 10³–10⁵ Hz, corresponding to Maxwell–Wagner relaxation. The dispersion coefficient α reaches maximums in two frequency ranges, decreasing with increasing oxygen content. EDS analysis showed a decrease in Ru content from ~24.9 at.% (0% O₂) to ~0.7 at.% (50% O₂) and an increase in oxygen content to ~78 at.% at 10% O₂. The results confirm the transition from metallic conduction to tunneling and hopping mechanisms with increasing oxidation state of the structure. Full article

This study presents a comprehensive review of more than 100 research papers on sign language recognition (SLR) published between 2020 and 2026. The analysis focuses on deep learning approaches applied to video-based SLR, including spatiotemporal feature extraction, temporal modeling, attention mechanisms, motion-based representations, hybrid frameworks, transfer learning methods and other methods. Particular attention is given to how these methods model spatiotemporal dynamics and capture subtle gesture characteristics in sign language communication. The review highlights several recent developments, such as the introduction of specialized datasets, the emergence of real-time recognition systems, and the integration of multimodal fusion strategies. At the same time, persistent challenges remain, including data scarcity in low-resource sign languages, limited linguistic standardization of datasets, and insufficient model interpretability. The findings underline the importance of developing scalable and generalizable models capable of handling diverse datasets and user variability. The distinct contributions of this review are fourfold: (1) a comprehensive synthesis of over 100 studies published between 2020 and 2026, covering the full spectrum of deep learning architectures for video-based SLR; (2) a structured six-category taxonomy enabling systematic cross-architectural comparison; (3) a comprehensive focus on low-resource sign languages, which remain underrepresented in the existing literature; and (4) a critical analysis of the current benchmark landscape for low-resource sign languages, identifying key gaps and outlining strategic directions for future dataset development. These contributions are intended to guide further research toward more robust, inclusive, and universally applicable SLR systems. Full article

The article presents the concept of using supercapacitor as an energy storage in a trolleybus in order to ensure the continuity of power supply to on-board trolleybus devices during the passage through isolated sections of the overhead contact line. A mathematical model of the on-board power supply system and an example of the power limit calculation have been described. The required capacity of the supercapacitor has been determined. A series of simulation studies were conducted, which made it possible to analyze and evaluate the potential capabilities and limitations of the proposed methods for maintaining the operation of auxiliary equipment. The results of simulation studies showed that the proposed model can be effectively used under typical trolleybus traction conditions. The use of a supercapacitor can ensure an uninterrupted power supply to auxiliary equipment across the entire range of operating speeds and power requirements of the trolleybus. Full article