Search Results (7,837)

To address the lack of comprehensive quality evaluation indicators for heat treatment after bilateral induction hardening of high-speed linear guide rails, this study draws on the concept of geometric tolerance to innovatively propose a quantitative evaluation indicator for the “symmetry” of the hardening layer depth profile, and conducts non-destructive evaluation research based on ultrasonic transverse wave backscattering technology. Aiming at the complex cross-sectional profile of the guide rail and the problem of anisotropic acoustic scattering, a multi-dimensional symmetry characterization framework driven jointly by “local pair-wise tolerance zone constraints” and a “global equivalent case depth metric” was established. This dual-driven evaluation framework effectively eliminates the evaluation loophole of “false symmetry” caused by the mutual cancellation of opposite positive and negative local deviations. By constructing an equivalent hardened layer model based on discrete feature point mapping, the interference of non-parallel complex curved surfaces on traditional continuous B-scan imaging is successfully circumvented, achieving stable characterization of the overall hardening layer coverage under specific process parameters. A 15 MHz water-immersed point-focusing ultrasonic transverse wave oblique incidence detection system was developed, paired with a self-designed spring-loaded passive conformal tracking clamping mechanism for continuous automated scanning. Experimental results demonstrate that the overall equivalent symmetry of the tested guide rail specimens remains above 98%. Verified by the metallographic Vickers hardness gradient method, the equivalent relative error between the ultrasonically measured case depth and the physical case depth is only 1.0% and 1.6%. This proves that this non-destructive evaluation method possesses excellent measurement accuracy and holds significant industrial value for online non-destructive monitoring. Full article

This study compares the microstructure, texture evolution, and mechanical behavior of Maraging 300 steel produced by selective laser melting (SLM) and conventional manufacturing (CM), subjected to solid solution treatment, cold rolling (up to 89.4% reduction), and aging. Results showed that while both routes achieved similar hardness, AM maintained stable hardness at extreme deformations, whereas CM peaked at 80.7% reduction. Tensile tests at ~80% reduction revealed that CM achieved higher ultimate tensile strength (2105 MPa) than AM (1807 MPa), but AM demonstrated superior ductility (16.7% vs. 10.8%). Electron Backscatter Diffraction (EBSD) analyses indicated that the AM material accommodated strain more homogeneously due to its initial fine cellular substructure, leading to greater crystallographic fragmentation, whereas CM exhibited pronounced strain localization. In conclusion, the initial microstructural state dictated by the manufacturing route fundamentally governs the deformation mechanisms, explaining the distinct strength–ductility balance observed between additively and conventionally processed Maraging 300 steel. Full article

Rockburst intensity prediction is commonly formulated as a hard-label classification problem, although rockburst grades are ordered, transitional, and often ambiguous under sparse geomechanical indicators. This study integrates three publicly available datasets to construct a 761-sample heterogeneous rockburst database using three common predictors: Stress Coefficient (SC), Brittleness Coefficient (BC), and Elastic Energy Index (EEI). Diagnostic analysis shows substantial adjacent-grade overlap and source-dependent feature shifts, indicating that conventional one-hot labels and random validation may be insufficient for robust intensity assessment. To address these issues, a Source-Invariant Ordinal Label Distribution Learning (SI-OLDL) framework is proposed. The framework generates neighborhood-adaptive ordinal soft labels to represent local grade ambiguity and introduces a source-confusion branch to reduce source-specific bias during training. Under repeated stratified random validation, SI-OLDL achieved an accuracy of 0.821 and a Macro-F1 of 0.824, showing performance comparable to XGBoost, which achieved 0.819 and 0.823, respectively. Under leave-one-source-out validation, SI-OLDL showed more favorable average cross-source ordinal performance within the tested benchmark, with a Macro-F1 of 0.856 and a severe misclassification rate of 0.020. These results suggest that modeling rockburst intensity as an ordinal risk distribution is a useful representation strategy for heterogeneous small-sample rockburst databases, while independent external validation remains necessary before broader engineering deployment. Full article

This study evaluated the effect of evening primrose seed, cold-pressed oil, and defatted seed meal on the fatty acid composition, tocopherol content, physical properties, sensory acceptance, and oxidative stability of dark chocolate. Samples were prepared under controlled laboratory conditions with 2.5% or 5% of the tested ingredients and stored for 8 months. All ingredients introduced α-linolenic and γ-linolenic acids, and increased tocopherol content, with the strongest effect observed in the oil-fortified chocolate. After storage, moderate losses of tocopherols were detected, while oxidation indices confirmed acceptable oxidative stability of the fortified chocolates. Viscosity dependent on the type of added ingredient, with the oil-containing formulation showing the most favorable technological profile. Color parameters remained largely unchanged, except for the sample with added oil, and hardness was affected mainly by seed and meal additions. Sensory scores remained within the acceptable range for all samples (5–8.5 points on a 9-point hedonic scale). Overall, evening primrose ingredients can be successfully used as functional additives in dark chocolate. Among the tested formulations, evening primrose oil provided the greatest improvement in the lipid profile and maintained acceptable physical and sensory properties. However, the slightly greater changes observed in this formulation may be important when determining shelf life. Full article

Marginal bone preservation around osseointegrated dental implants continues to represent a critical challenge in modern implant dentistry. To address this issue, subcrestal implant placement along the apico-coronal axis has been proposed as a reliable clinical strategy aimed at reducing the risk of implant thread exposure within the oral environment. In the present study, 38 healthy patients were treated with either bone-level implants (BLG-Control) or implants positioned 2 mm subcrestally (SCG-Test). All implants featured an internal conical connection and a platform-switching design. In addition, implants in the test group were restored using an immediate tissue-level abutment following the one-time abutment (OTA) protocol. Marginal bone modifications (MBMs) were evaluated through standardized radiographic examinations performed at surgery (T0), implant loading (T1), and after 6 (T2), 12 (T3), 24 (T4), and 36 (T5) months of functional loading. MBMs, meaning the overall changes in the radiographic bone structure over time, were categorized as bone loss (BL) when occurring apical to the implant neck, and as bone remodeling (BR) when detected coronally to the implant neck. Clinical parameters, including probing pocket depth (PPD), bleeding on probing (BoP), and plaque index (PI), were also recorded and analyzed throughout the follow-up period. At the 36-month evaluation, mean MBM values were 0.61 mm for the test group and 0.58 mm for the control group. After three years of follow-up, the test group demonstrated a mean PPD of 2.03 mm, compared with 2.78 mm in the control group. Bleeding on probing was recorded at 13% in the test group and 11% in the control group, while plaque index values were 11% and 5%, respectively. Within the limitations of the present investigation, implants placed 2 mm subcrestally and characterized by an internal conical connection combined with platform switching demonstrated favorable clinical and radiographic outcomes over a short- to medium-term observation period of three years. When compared with equicrestally positioned implants, the subcrestal approach seemed to favor the peri-implant hard tissue conditions while reducing the possibility of marginal bone loss below the implant neck. However, one should bear in mind that this clinical behavior applies specifically to the investigated implant design and should be interpreted within the limitations of the present study. Full article

Software defect prediction (SDP) aims to identify defect-prone modules before testing, but severe class imbalance and redundant software metrics often limit prediction performance. Many conventional feature selection methods estimate feature relevance with the original imbalanced empirical distribution and mainly emphasize marginal relevance or global classifier-oriented criteria, which may under-prioritize features that are informative for the minority defective class. To address this issue, this paper proposes SCAR-CMB, a simplified class-reweighted and interaction-aware feature selection method for imbalanced SDP. SCAR-CMB estimates feature-label dependency with a class-balanced empirical distribution, controls redundancy using weighted conditional dependency information, and incorporates an interaction-aware conditional-gain term as an auxiliary re-prioritization signal within a relevance-screened feature pool. Rather than performing full causal structure discovery or formal synergy estimation, SCAR-CMB adopts a Markov-blanket-inspired conditional dependency design as a practical guide for feature selection. The final configuration excludes both hardness-aware weighting and false discovery rate filtering. SCAR-CMB is evaluated on ten public NASA and PROMISE defect datasets under a leakage-free cross-validation protocol. Compared with seven representative baselines, SCAR-CMB achieves competitive overall performance and obtains the highest average defective-class recall, G-mean, and balanced accuracy. However, it is not uniformly superior across all metrics, and the recall advantage is not confirmed by the omnibus Friedman test. Additional mechanism-level, stability, and sensitivity analyses show that class reweighting changes feature prioritization, the selected feature subsets are relatively stable across folds, and the interaction-aware term provides limited and dataset-dependent auxiliary effects. Sensitivity analyses further indicate that the main conclusions are not solely determined by a specific feature budget, discretization-bin setting, or downstream classifier. Overall, SCAR-CMB should be interpreted as a practical minority-class-oriented feature selection method that provides a trade-off among defective-class detection, feature subset control, and computational cost. Full article

Post-disaster recovery is a multi-year, multi-dimensional process, yet most remote-sensing assessments rely on single indicators and are hard to apply in data-sparse regions—limiting their value for sustainable, evidence-based reconstruction. We develop a Google Earth Engine (GEE)-based multi-sensor Recovery-Activity Index (RAI), built entirely from free satellite data, and apply it to the 2023 Al Haouz earthquake (Mw 6.8) in the High Atlas, Morocco. The index is framed explicitly as an observed recovery-activity monitoring proxy, not a direct measure of welfare or resilience capacity. Monthly VIIRS nighttime-light (NTL) anomalies, Dynamic World built-up probability, and precipitation-corrected Sentinel-2 NDVI were extracted for a 30 km rural core zone (January 2022–May 2026), deseasonalized, standardized, and integrated. NTL anomalies rose after the earthquake (post-event mean +18%) and appeared to precede built-up anomalies by about two months; because monthly series are short and autocorrelated, we tested this lead with block-bootstrap and block-permutation methods and report it as a reproducible but modest early-activity lead (r = 0.65, p = 0.02; p = 0.14 after correction) that is not an artefact of optical data gaps. NDVI was governed mainly by precipitation (R² = 0.61) with negligible earthquake-attributable change, so vegetation signals do not confound the index. The integrated RAI peaked in December 2024 and proved robust to indicator weighting (pairwise r ≥ 0.97), baseline choice (r = 0.88), and spatial domain (<9% variation), with a genuinely multi-sensor peak (NTL 62%, built-up 43%). Province-level analysis revealed an uneven recovery hierarchy (Chichaoua > Al Haouz > Taroudannt) driven by differences in physical-rebuilding signal rather than baseline luminosity. Running in minutes server-side at no cost, the RAI offers data- and resource-limited administrations a scalable, reproducible tool to flag where reconstruction activity lags and to prioritize targeted ground verification—supporting more equitable, sustainability-oriented recovery governance—rather than serving as a stand-alone, validated recovery measure. Full article

CoCrNiTiAl_x high-entropy alloy films with varied Al contents were fabricated on 42CrMo steel substrates via magnetron sputtering. By adjusting the sputtering power of the Al target, an investigation was systematically carried out to explore the effect of different Al contents on the microstructural evolution, mechanical properties, and corrosion resistance of the film, with the underlying synergistic mechanism governing these properties being elucidated. With increasing Al content, the film microstructure gradually transforms from an amorphous phase at low Al contents to a nanocrystalline–amorphous composite structure, until it is converted into the BCC phase, and the film’s crystallinity exhibits a trend of first increasing and then decreasing. In terms of mechanical properties, the film hardness is significantly enhanced from 7.6 ± 1.3 GPa to 18.9 ± 1.1 GPa with increasing Al content, while the toughness gradually declines. Wear tests show that the film wear rate first decreases and then increases with rising Al content, reaching a minimum of 2.06 × 10⁻⁵ mm³/N·m. The superior protective state, characterized by a corrosion potential reaching −361.2 mV and corrosion current density dropping to 1.12 μA/cm², arises from the generation of an integrated, consistently structured composite passivation barrier in 3.5 wt.% solution. This study confirms that appropriate Al doping can synergistically optimize the microstructure, mechanical properties, and corrosion resistance of CoCrNiTiAl_x films, providing experimental and theoretical support for the compositional design and engineering applications of high-performance high-entropy alloy protective films. Full article

The effects of red seaweed, psyllium husk, and chia seeds on the structural and functional properties of comminuted meat batters were evaluated. Meat batters were formulated with 1% of each ingredient or their combinations totaling 1% and evaluated for pH, cooking loss, microstructure, texture profile analysis, color, rheology, and protein interactions. Formulation did not affect (p ≥ 0.08) pH or cooking loss, indicating that water- and lipid-holding capacity and emulsion stability were preserved across treatments. Hardness increased (p ≤ 0.05) in treatments containing red seaweed, alone or combined with psyllium husk. Fiber addition did not influence (p ≥ 0.17) raw batter color; however, cooked products showed differences (p ≤ 0.05) in lightness (L*) and total color change (ΔE*). Rheological analysis indicated similar viscoelastic behavior among treatments with no significant differences among treatments (p ≥ 0.07) for storage modulus, loss modulus, or tangent delta at the start, peak, or end of the small-amplitude oscillatory shear test. Microstructural observations revealed treatment-dependent networks, and protein solubility analysis showed changes (p ≤ 0.05) in ionic and hydrogen bonding, while disulfide bonds were unaffected (p = 0.60). Incorporation of 1% of these ingredients maintained desirable physicochemical, textural, and functional properties, highlighting their potential as ingredients in meat batters. Full article

This study investigates the properties of WC–10Ni cermet coatings deposited by plasma spraying using two different plasma torches: a conventional A60 torch (APS) and an advanced Axial III torch (HV-APS). The aim of the work was to compare the microstructure, porosity, surface roughness, phase composition, and mechanical properties (hardness and instrumented indentation), as well as erosion, scratch response, and resistance to tribological wear of the obtained coatings. The coatings were deposited onto S235 steel substrates using WC–10Ni (WOKA 3302) powder. The results revealed that both coatings exhibit a typical lamellar structure characteristic of plasma-sprayed materials; however, distinct differences in surface roughness, porosity, and mechanical response were observed. The coating produced using the Axial III torch showed lower porosity (~6%) and higher hardness (~1000 HV) compared to the coating deposited with the A60 torch (~12% porosity and ~831 HV). Phase analysis confirmed the presence of WC, W₂C, and Ni in both coatings, indicating partial decarburization of carbides during the spraying process. Erosion resistance tests did not reveal significant differences between the coatings. Erosion testing revealed comparable performance for both coatings, with erosion rates of approximately 0.7 mg/min. Scratch testing showed significantly lower acoustic emission activity for the Axial III coating, indicating less intensive fracture-related events during loading and confirming its more compact microstructure. In contrast, ball-on-disk tribological tests demonstrated comparable wear rates for both coatings (≈9 × 10⁻⁵ mm³·N⁻¹·m⁻¹), despite the substantially higher hardness of the Axial III coating (1010 HV0.2 compared with 792 HV0.2 for the A60 coating). These results indicate that the improvements in hardness and coating densification achieved by the HV-APS process did not result in a measurable reduction in steady-state sliding wear under the applied test conditions. Full article

This paper addresses the challenge of integrated optimization for storage space allocation and crane scheduling in Automated Storage and Retrieval Systems (AS/RSs) under the complex constraints of dual I/O ports and Shared Storage strategies. The scheduling of multi-shuttle cranes in such environments constitutes a highly coupled NP-hard combinatorial optimization problem, where task assignment, sequencing, and dynamic storage location allocation must be solved simultaneously. To tackle this, this paper proposes an Elite-Driven Synchronized-Repair Memetic Algorithm (ED-SRMA) based on a sensor-informed total-travel-time objective formulated from horizontal and vertical crane displacements that can be measured by the crane drive sensors. The method combines a dual-layer representation, cross-layer synchronization, a problem-specific feasibility-repair operator, elite preservation, and budgeted local refinement. Numerical experiments were conducted on seven problem scales using 30 paired independent runs and a fixed evaluation budget. Compared with the corresponding dual-I/O operating mode without immediate location reuse, the shared-storage RS mode reduced the mean total travel time by 4.57–14.89%. ED-SRMA reduced the mean objective value by 5.48–39.59% relative to Base-GA and by 3.99–28.82% relative to PSO. For the representative $120\times 5$ instance, the fitness-evaluation-based convergence analysis further shows an earlier objective-value reduction and continued improvement under the common evaluation budget. These results demonstrate the effectiveness, statistical significance, and consistency under the tested conditions of ED-SRMA for the investigated dual-I/O shared-storage scheduling problem. Full article

This study presents a calibrated modelling approach for predicting the abrasive wear of copper-free composite friction materials. Four formulations were analysed, including a copper-containing reference material and three experimental compositions in which copper was replaced by different aluminium/polytetrafluoroethylene ratios. Dry ball-cratering tests were performed to determine the apparent wear-rate coefficient under controlled laboratory conditions. The copper-containing reference material showed the lowest wear-rate coefficient, k_c = 80.655 × 10⁻¹⁴ m²·N⁻¹, whereas the copper-free formulations reached k_c = 111.811 × 10⁻¹⁴ m²·N⁻¹, 98.586 × 10⁻¹⁴ m²·N⁻¹ and 90.579 × 10⁻¹⁴ m²·N⁻¹ for S2, S3 and S4, respectively. Thus, copper replacement increased the apparent wear-rate coefficient by approximately 12–39%, depending on the Al/PTFE ratio. The obtained data were used to develop and compare four calibrated predictive models. Among them, the modified Hertz–Archard model, which included effective hardness and contact-related descriptors, provided the best agreement with the experimental data. This model achieved MAPE = 1.5%, RMSE = 2.181 × 10⁻¹⁴ m²·N⁻¹ and a maximum absolute error of 4.3%, with all predictions within the ±5% error band. The results indicate that the proposed calibration framework can support preliminary screening and ranking of copper-free friction-material formulations under the adopted dry ball-cratering conditions. Full article

The use of bulk heat treatments to improve the resistance of the material structures to cavitation erosion remains an effective approach due to the beneficial modifications induced in the microstructure and physical-mechanical properties. Depending on the intensity of cavitation loading, various heat treatment regimes can be applied. Among these, artificial aging treatments are particularly suitable for non-ferrous alloys, especially aluminum, zinc, and magnesium-based alloys. The current study investigates the effect of artificial aging heat treatment performed at 250 °C with holding times of 12 and 24 h on the biodegradable magnesium-based AM50 alloy. Cavitation tests were carried out using the method with a stationary specimen on a standard vibratory device according to ASTM G32-2016 requirements. The analysis of cavitation-eroded surfaces through macro- and microstructural images, together with the interpretation of characteristic erosion curves and specific parameters (cumulative mass loss, erosion speed and cavitation resistance), revealed both similarities and significant differences governed primarily by surface hardness and microstructural features. Comparison with the initial (semi-finished) state and with previous studies on artificial aging treatments performed at 200 °C for 12 and 24 h confirms the similarly beneficial effect of the 250 °C aging regime on the cavitation erosion resistance of the AM50 alloy. Full article

In the context of increasing environmental awareness and the transition toward a circular material economy, the development of sustainable polymeric materials has become a key focus of industrial research. Within this framework, thermoplastic elastomers (TPEs) represent a promising class of materials that combine the elasticity of rubbers with the processability and recyclability of thermoplastics. Their ability to incorporate recycled content further enhances their potential for reducing environmental impact in advanced automotive applications. This study investigates styrenic thermoplastic elastomers (TPS) based on a SEPS (Styrene–Ethylene–Propylene–Styrene) and polypropylene matrix containing over 50% recycled content, with the aim of evaluating the influence of recycled material on structure and performance. TGA, DSC, and ATR-FTIR analyses revealed comparable degradation behavior and similar chemical features between virgin and recycled compounds, while minor differences were possibly related to variations in the plasticizer fraction and polymer-oil interactions. These differences did not significantly compromise the mechanical integrity of the recycled materials under the conditions investigated. Mechanical tests (tensile, tear, hardness, compression set) confirmed that recycled TPS maintains mechanical performance comparable to virgin formulations, while accelerated weathering resulted in minimal color variation and excellent surface appearance retention. Overall, TPS with high recycled content exhibit stable thermal, chemical, and mechanical behavior, confirming their suitability as sustainable alternatives for automotive components. Full article

To overcome the insufficient hardness and wear resistance of CoCrFeNi alloy coatings under heavy-load conditions, CoCrFeNi-TiC composite coatings with varying TiC mass fractions were fabricated on a 42CrMo substrate using laser cladding. The present study systematically investigates the effects of TiC content on phase composition, microstructural evolution, microhardness, and tribological behavior. The results show that TiC addition does not change the primary phase constitution of the face-centered cubic (FCC) matrix, but induces lattice distortion and grain refinement, resulting in a pronounced enhancement of coating hardness. As the TiC content increased, the average microhardness rose from 222.9 HV_0.2 to 380.9 HV_0.2, which was 1.7 times that of the coating without TiC. The enhanced hardness is mainly attributed to grain refinement, solid-solution strengthening, and the dispersion effects of TiC particles. The tribological performance showed a non-monotonic dependence on TiC content. Among the tested samples, the coating with 10 wt.%TiC showed the best wear resistance, with an average friction coefficient of 0.56 and a wear rate of 1.15 × 10⁻⁴ mm³/(N·m). However, further increasing the TiC content to 15 wt.% slightly reduced wear resistance because particle spalling promoted three-body abrasive wear. These results indicate that an appropriate TiC content can improve the balance between hard-phase strengthening and wear stability of CoCrFeNi-based composite coatings. This work clarifies the microstructure regulation and wear failure mechanism of TiC-reinforced coatings, providing experimental guidance for heavy-load service coating design. Full article