Search Results (4,896)

Scan-assisted interocclusal registration may vary with record extent and occlusal support. Using separately fabricated high-hardness vinyl polysiloxane (VPS) records, a fixed bilateral buccal intraoral scanner (IOS) acquisition protocol, optical reference articulations, and position-level three-dimensional analysis, this in vitro study compared prepared-tooth (Hard-Prep) and complete-arch (Hard-Arch) records across three support configurations and assessed a no-record IOS workflow. Ninety VPS-based and 45 no-record IOS acquisitions were analyzed. VPS records were fabricated under a 3.0 kg load; measurements used a 1.0 kg load. Overall three-dimensional deviation (dXYZ) was averaged over five mandibular positions. Log-transformed dXYZ was analyzed by ordinary least squares with Holm-adjusted contrasts. The Hard-Arch/Hard-Prep contrast was not statistically significant under bilateral extended support. Hard-Arch showed higher dXYZ under unilateral extended support (ratio, 1.75; 95% confidence interval (CI), 1.54–1.99; p < 0.001) and unilateral limited support (ratio, 1.58; 95% CI, 1.39–1.80; p < 0.001). In the no-record workflow, unilateral extended support exceeded bilateral extended support (ratio, 1.50; 95% CI, 1.31–1.72; p < 0.001), whereas unilateral limited support was lower than unilateral extended support (ratio, 0.68; 95% CI, 0.59–0.77; p < 0.001). Prepared-tooth records yielded lower deviation in both unilateral configurations, while the no-record workflow varied with support configuration. Full article

Tunnel excavation in ground comprising a soft upper stratum and a hard lower stratum posed significant challenges, particularly during invert construction using drilling-and-blasting methods, which could disturb the surrounding rock and the installed support system. To address these issues, this study evaluates the feasibility of an alternative support scheme that eliminates the invert by employing expanded arch feet, thereby utilizing the self-bearing capacity of the underlying hard stratum. Both physical model tests and numerical simulations were conducted to compare the structural performance of a conventional lining with an invert against the proposed expanded arch foot lining. Based on the strain measurements and earth pressure cell readings from the physical model tests, together with the internal force and contact pressure results obtained from the numerical simulations, the axial force, bending moment, and contact pressure between the lining and surrounding rock were compared for the two lining schemes. The safety factors were further calculated using the axial force and bending moment at representative sections. The results showed qualitatively consistent trends between the tests and simulations. Compared with the conventional invert lining, the expanded arch foot lining increased the axial force and bending moment at the arch foot and sidewall by 7.95% and 29.60%, respectively, while slightly reducing those at the crown by 4.44% and 3.09%. This indicates that part of the structural demand is transferred from the crown to the arch foot and sidewall, where the enlarged sections provide greater bearing capacity. The contact pressure distributions of the two lining schemes were different. Owing to its closed structural form, the conventional invert lining produced a more favorable contact pressure condition at the sidewall. In contrast, the expanded arch foot lining showed higher safety factors at the arch foot and sidewall, with increases of 89.80% and 36.00% in the model tests and more than 140% in the numerical simulations. Meanwhile, the internal force distributions of the two lining schemes remained generally comparable. These findings indicated that the lining with expanded arch feet provided sufficient structural capacity at critical sections and could serve as a feasible alternative to the conventional lining with an invert, while avoiding the construction-related disadvantages associated with invert excavation. Full article

In silico studies of microbiological systems are essential for predicting and controlling the impact of external factors on bacterial communities. Quorum sensing represents one of the key mechanisms of bacterial communication, particularly in pathogenic bacteria, realized as a cell-density-dependent regulatory process governed by diffusible signaling molecules. The present study proposes a Physics-Informed Neural Network (PINN)-based computational framework for a spatially independent model of bacterial quorum sensing and population dynamics. The approach solves both the forward and inverse problems for a spatially independent model formalized by a system of nonlinear ordinary differential equations. The forward problem is solved numerically by reconstructing the dynamics of three key characteristics: signaling molecule concentration, degrading enzyme concentration, and bacterial biomass density. The obtained PINN solutions are compared with numerical solutions computed using the Radau IIA implicit Runge–Kutta method. The inverse problem capability is evaluated by recovering system parameters that are difficult to measure directly in experimental settings. The framework is implemented using the DeepXDE library with a PyTorch backend, employing hard constraints for initial conditions, singularity-avoiding loss reformulations, and a multi-stage Adam–L-BFGS optimization strategy. Validation is performed on a Monod chemostat benchmark and the Pseudomonas putida IsoF quorum sensing regulatory network. The proposed PINN-based framework extends the applied mathematical toolkit for in silico studies of microbial systems, enabling accurate reconstruction of emergent population dynamics and robust inference of regulatory parameters that are inaccessible to direct experimental measurement. Full article

Climate policy uncertainty (CPU) suppresses corporate investment broadly, but its effect is not uniform across firms. Using a sample of 60,185 firm-year observations for nonfinancial U.S. firms from 1990 to 2024, this paper shows that industry-adjusted real-estate concentration within the hard-asset base moderates the investment response to CPU. Firms with more real-estate-concentrated tangible assets have lower investment rates on average ($\beta =-0.042$, $t=-18.3$), but under high climate policy uncertainty this negative relation is significantly attenuated in the continuous CPU specification ($t=5.88$). The attenuation is consistent with a structural floor: real-estate-heavy firms already operate in a conservative investment regime, so the additional delay induced by CPU falls disproportionately on firms with more discretionary capital deployment. The financing evidence is mixed rather than uniformly null: leverage interactions are negative (inconsistent with a collateral mechanism), and cash rises modestly under high CPU, but neither pattern absorbs the core investment interaction, pointing to real capital budgeting rather than financial structure as the dominant margin. The result is robust across alternative CPU measures and core specification checks. The evidence is associational rather than causal, but it identifies real-estate concentration as a novel, financial-statement-observable source of firm-level heterogeneity in how climate policy uncertainty transmits to corporate investment, distinct from the aggregate policy shocks, financing constraints, and industry membership emphasized in prior work. Full article

Polyhydroxyalkanoates (PHAs) are biodegradable biopolymers with high application potential, representing an alternative to petrochemical-derived plastics. The aim of this study was to evaluate the processing and mechanical properties of the commercial PHA EM20010 material intended for injection molding. Particular attention was paid to analyzing the effect of process parameters on the material’s flowability in the injection mold and determining the basic functional properties of the resulting molded parts. The tests included a technological flowability test using an Archimedes spiral mold, a static tensile test, Charpy impact testing, Shore D hardness measurements, and water absorption assessment. The results obtained showed that the tested material was characterized by a high tensile strength of 66.8 ± 1.8 MPa and a Young’s modulus of 1322 ± 21 MPa. Elongation at maximum stress reached 5.0 ± 0.5%, indicating the relatively stiff nature of the material. The average unnotched impact strength was 24.8 ± 3.5 kJ/m², while hardness ranged from 54.6 to 55.4 ShD. Water absorption tests revealed very low water absorption of approximately 0.11% after 24 h of exposure. The flushing test confirmed the significant effect of injection temperature and pressure on the material’s flowability. The maximum spiral length of 54.8 cm was achieved at a processing temperature of 175 °C and an injection pressure of 100 bar. The tests demonstrated that this material possesses a favorable combination of high strength, good toughness, low water absorption, and good processing properties. Full article

The transformation of toluene to benzaldehyde via green and sustainable routes is of great significance in the fine chemical industry. However, hard activation of benzylic C(sp³)-H bonds and facile overoxidation of the generated benzaldehyde collectively render the selective oxidation of toluene extremely challenging. In this study, we constructed a core–shell heterostructure photocatalyst, CeO₂@NiFe-LDH, employing molecular oxygen as the oxidant. Under mild conditions of room temperature and visible-light illumination, the catalyst achieves a toluene conversion rate of 1.936 mmol·g⁻¹·h⁻¹ with an excellent benzaldehyde selectivity of 81.0%, and its catalytic performance is significantly superior to that of the individual single-phase materials and the simple physical mixture. Optical and electrochemical measurements confirm enhanced visible-light absorption and utilization, as well as greatly improved separation and migration efficiency of photogenerated charge carriers. Furthermore, the CeO₂@NiFe-LDH heterostructure features staggered band alignment, promoting S-scheme charge transfer across the heterointerface, thereby substantially boosting the redox capacity of the composite catalyst. Consequently, the photogenerated carriers with high reactivity are fully engaged in catalytic reactions, enabling efficient carrier utilization and ultimately leading to a significantly enhanced photocatalytic performance. This study not only demonstrates the outstanding application potential of CeO₂@NiFe-LDH for the visible-light-driven selective oxidation of toluene to benzaldehyde, but also offers a novel strategy for enhancing the photocatalytic performance of LDH-based materials. Full article

Heat-polymerized poly(methyl methacrylate) (PMMA) is widely used for denture bases but remains susceptible to surface deformation and sliding wear. This study evaluated the structure, chemistry, surface morphology, microhardness, and dry-sliding tribology of PMMA reinforced with 1, 3, and 5 wt.% cubic boron nitride (c-BN). Disk specimens (10 mm diameter × 2 mm thickness) were prepared; ten specimens per group were tested for Vickers microhardness and wear/coefficient of friction, while one representative specimen per group was examined by XRD, ATR-FTIR, and SEM/EDS before and after wear. The PMMA amorphous/semi-amorphous response and characteristic ester bands were retained, whereas c-BN-related diffraction features and B/N signals became more evident with reinforcement. Microhardness increased from 20.00 ± 0.70 to 45.00 ± 1.61 HV0.03. After 1000 m at 10 N and 1 m s⁻¹, mass loss decreased from 32.4 to 9.8 mg and the overall coefficient of friction from 0.58 to 0.28. Post-wear SEM/EDS showed reduced grooving, smearing, and material detachment at higher c-BN contents. Statistical analysis confirmed large composition effects, and composition-window models reproduced the measured hardness and wear trends. Within the tested range, 5 wt.% c-BN provided the strongest surface-hardening and wear-suppression response under controlled dry-sliding conditions. Full article

Laboratory friction measurements are central to material screening for High-Friction Surface Treatments (HFST), yet metrological aspects including a proposed metrological traceability framework or uncertainty, and reproducibility are consistently underreported. This study applies a metrology-aligned framework to British Pendulum Tester (BPT) measurements performed in three states: dry, wet (water), and water–soap to assess operational adhesion and hysteresis components, document traceability to the International System of Units (SI), and report GUM-style uncertainty with covariance for the adhesion difference. Measurements were obtained for calcined bauxite (CB) and rhyolite (Rhy) in HFST and Coarse gradations across seven polishing protocols (baseline; LAA-1000/2000; MDA-105/180; PSV-10 h/20 h), using n = 3 replicates per Treatment × Material × State. Replicate-based Type A uncertainties were combined with instrument/system Type B components geometry, slider hardness, temperature, soap film consistency, and calibration to yield combined u_c and expanded uncertainty U_(k=2). The Wet–Soap cross treatment physical correlation ellipses demonstrate strong positive correlations (r ≈ 0.88–0.98; p < 0.001) between wet and soap states, supporting the interpretation that wet friction is governed primarily by hysteresis, with adhesion acting as a small offset under BPT kinematics. The slider hardness and temperature typically control the wet state uncertainty budget; including measured Wet–Soap covariance reduces adhesion U_(k=2) by up to ~6.5%, consistent with GUM’s law of uncertainty propagation. Together, these measurement science practices enhance road safety by making laboratory friction data traceable, comparable, and decision-ready. Full article

Primary implant stability arises from mechanical engagement at placement, and insertion torque is not a direct measure of osseointegration. This retrospective single-centre study included 101 MultiNeO titanium implant placements in 55 adults treated between April 2023 and January 2026. Four experienced operators placed implants subcrestally using a W&H Implantmed SI-1023, a bone-resistance-adapted drilling protocol, and a programmed target of 35 N·cm. Associations with recorded torque were assessed using a patient-clustered Gaussian generalized estimating equation adjusted for sex, age, anatomical sector, implant length and diameter, hard-tissue augmentation, and placement timing. The mean torque was 31.63 ± 5.57 N·cm; the median was 35 N·cm (Q1–Q3, 30–35). Recorded torque was 3.25 N·cm higher for implants placed in women than for those placed in men (95% CI 1.20–5.31; p = 0.002). Relative to maxillary anterior/premolar sites, mandibular molar sites showed higher torque (β = 4.02; p = 0.001), whereas mandibular anterior/premolar sites showed lower torque (β = −5.41; p = 0.013). Implant length had a modest adjusted association (β = 0.93 N·cm/mm; p = 0.022); age, diameter, augmentation, and placement timing did not. The concentration of recorded values at 35 N·cm reflects a clinical target rather than the device limit. These exploratory associations do not establish an intrinsic sex effect or predict osseointegration, and residual confounding due to unmeasured bone characteristics remains possible. Full article

Vocal rise time (VRT) acoustically measures from when vocal cord vibration begins to when phonation achieves a peak steady state. This acoustic-based study examines manual and automatic VRT measurements based on different vowel onset recordings (e.g., hard, modal, soft) from four datasets containing 146 adult Australian English-speaking females. Experiments test how the automatic Voice Onset Analysis Tool (VOAT) settings impact VRT measurement estimations. When compared to VOAT VRT baseline setting results, parameter adjustments using a Hilbert envelope 400 ms analysis segment with a low smoothing factor decreased VRT mean absolute error as low as 15.5 ms and 21.3 ms for modal and soft onsets, respectively. While the automated VOAT demonstrates objective repeatability with accelerated VRT extraction time advantages, still experiments herein show that the proposed adjusted settings are least accurate for hard onsets, whereby a mean absolute error as high as 71.0 ms is reported. Given three to five voice therapy sessions, females with voice disorders exhibited an 11% increase in VOAT VRT durations with reduced variation (6%), providing preliminary clinical evidence that this measure can assist in monitoring patients’ progress. This study reveals cross-corpora VRT norms per voice onset type, discusses VOAT parameter effects, and supports future automated VRT algorithm considerations. Full article

Rail light-strip morphology reflects the wheel-rail contact condition. Reliable automatic analysis remains difficult. The strip is narrow and has weak boundaries, while specular reflection, rail-head texture and trackside background interfere with color inspection images. This study proposes a segmentation-guided geometric method for rail light-strip abnormality analysis. An improved SegFormer jointly segments the background, rail-head and light-strip regions. A boundary detail enhancement module refines weak rail-head and light-strip contours. Focal Loss emphasizes minority and hard boundary pixels. The rail-head mask provides the geometric reference for extracting the light-strip centerline, eccentricity, width sequence and connected-component morphology. The predicted masks are ordered using the corrected mileage record. Every 1000 original-resolution rows then form a consecutive 1 m detection unit. When a geometric rule is triggered, the method reports that unit’s 1 m mileage interval together with its eccentricity, width-change or local-integrity measurement. The model achieves 95.67% mean Intersection over Union (mIoU) on 3520 annotated images. It detects 845 of 876 positive units, with 96.46% recall, 89.23% precision and 92.70% F1-score. The resulting records identify abnormal 1 m mileage intervals and report the corresponding eccentricity, width-change, or local-integrity measurements for targeted manual review. Full article

The structure, mechanical and electrical properties of Zr-based melt-spun Zr–(Al)–Ni–Cr–Ag alloys were investigated as a function of elemental composition. X-ray diffraction reveals the structural evolution from fully amorphous to nanocrystalline states, with the latter containing Zr₂Ni “big-cube” (space group Fd3̄m, cF96), fcc-Zr₂Ni, and β-Zr phases depending on the alloying ratio: Cr-rich compositions (≥15 at.%) stabilize β-Zr within the amorphous matrix, whereas Ag-enriched alloys promote “big-cube” phase formation. Ag atoms can replace both Zr and Ni sites in the “big-cube” lattice, yielding a (Zr,Ag)₂(Ni,Ag) solid solution and highlighting its role as a structural bridge between the amorphous and crystalline states. Nanoindentation measurements show that hardness increases from 6.5 GPa in fully amorphous ribbons to 10.12 GPa in three-phase nanocrystalline composites, with an H/E ratio of ~0.08 indicating predominantly covalent bonding, and the fracture strength of the amorphous alloys is ~2 GPa, exceeding literature values for related Zr-based systems. Electrical resistivity measurements over the 4–298 K range show that most alloys deviate from Matthiessen’s rule, exhibiting a negative temperature coefficient of resistivity consistent with the Mooij correlation; the presence of the icosahedrally ordered “big-cube” phase further increases resistivity relative to fully amorphous alloys. Full article

This paper presents a physiological signal-guided uncertainty-management framework that integrates real-time indicators of the operator’s supervisory state into UAV autonomy to improve obstacle avoidance and risk-aware decision-making under uncertain conditions. During UAV supervisory control, multimodal physiological signals, including heart rate variability, blood pressure, electrodermal activity, and other cardiovascular or stress-related measures, are time-synchronized with UAV telemetry, perceived obstacle fields, planner confidence, environmental uncertainty estimates, and operator intervention logs, including waypoint edits, overrides, and replanning commands. These heterogeneous data streams are fused using a Bayesian hierarchical state-space framework to estimate latent supervisory states representing trust miscalibration, risk sensitivity, and situational-awareness degradation. The estimated states are then incorporated into the UAV decision-making stack as bounded uncertainty-management parameters that regulate safety margins, replanning priority, and risk preference without relaxing hard safety constraints. The framework was evaluated in a simulation-based human-in-the-loop study involving 24 operators and 180 UAV obstacle avoidance missions. Performance was assessed using held-out-operator mission success AUROC, proxy-state RMSE, mission success rate, mean minimum obstacle clearance, mission risk index, operator override rate, and replanning latency. The results support the feasibility of using physiological, behavioral, vehicle, and environmental information to adapt UAV supervisory control to uncertainty in both the operating environment and human supervisory readiness. Full article

This study presents a comparative evaluation of the wear performance of three hot-work tool steels—WCLV (1.2344), Uddeholm Unimax, and Uddeholm QRO 90 Supreme—for die forging applications. The materials were characterized in terms of hardness and bulk chemical composition using Vickers hardness testing and X-ray fluorescence spectroscopy. Tribological behavior was investigated using ball-on-disc tests, while industrial performance was assessed by analyzing forging punches after the production of 16,250 components. Surface degradation was quantified using optical profilometry and three-dimensional roughness parameters. Measured hardness values were 591 HV for WCLV, 622 HV for QRO 90 Supreme, and 639 HV for Uddeholm Unimax. The average friction coefficients were 0.88, 0.92, and 0.77, respectively. Unimax also exhibited the lowest volumetric wear, reaching 0.04683 mm³ (R19 mm) and 0.03384 mm³ (R22 mm), compared with 0.08646–0.13095 mm³ for WCLV and 0.09598–0.13635 mm³ for QRO 90 Supreme. This corresponds to approximately 45–70% lower wear relative to the other steels. Industrial trials confirmed improved surface stability of Unimax punches after service. The observed trends are consistent with differences in alloying content and the expected microstructural response associated with chromium and molybdenum additions. Overall, Uddeholm Unimax demonstrated the most favorable balance of hardness, friction behavior, and wear resistance. Full article

Poly (vinyl chloride) (PVC) is widely used in many products due to its increased flexibility and processability. It is preferred in many industrial applications, especially in the plasticized PVC cable industry due to its excellent insulation properties. PVC is quite hard and can be difficult to process. Therefore, it requires additives such as plasticizers. Plasticizers typically reduce the glass transition temperature (Tg) and provide flexibility by reducing the workable temperature level. In the PVC compound production industry, phthalate-based plasticizers are preferred due to their low cost. Commonly used plasticizers are adipates, azelates, trimethylates, phthalates, benzoates, and chlorinated paraffins. The aim of the study was to investigate the plasticizer changes in PVC compounds used in cable insulation applications by synergistic effects of adipate, trimellitate, and phthalate-based plasticizers such as dioctyl terephthalate (DOTP), 2-ethyl hexyl adipate (DOA), and tris(2-ethylhexyl) benzene-1,2,4-tricarboxylate (TOTM). In this study, the effects of plasticizer additives were investigated on the structural, morphological, thermal, and mechanical properties of PVC compounds in the cable industry. Fabricated test products were characterized using characterization methods such as Fourier transform infrared-attenuated total reflectance (FTIR-ATR), scanning electron microscope–energy-dispersive X-ray (SEM-EDX) spectroscopy, thermal gravimetric analysis (TGA), tensile test, and density test. Successfully fabricated samples were tested before and after aging. The highest elongation at break of PVC flat sheet (244.96%) was obtained with the use of DOA plasticizer. The highest tensile strength was measured as 17.85 MPa for the sample containing 50 phr DOTP. Furthermore, no significant mass loss was observed up to 238 °C, while substantial decomposition occurred in the samples containing 50 phr DOTP, 50 phr DOA, and 50 phr TOTM between 238–338 °C, followed by gradual degradation at 483 °C and 683 °C. As a result, it has been determined that the use of DOA plasticizer in PVC compounds used in the cable industry is more effective than DOTP and TOTM plasticizers. Full article