Search Results (165)

With increasing quality demands in pharmaceutical and cosmetic packaging, this work presents a unified inspection platform for transparent ampoules that synergistically integrates stress measurement, dimensional measurement, and surface defect detection. Key innovations include an integrated system architecture, a shared-resource task scheduling mechanism, and an optimized deployment strategy tailored for production-like conditions. Non-contact residual stress measurement is achieved using the photoelastic method, while telecentric imaging combined with subpixel contour extraction enables accurate dimensional assessment. A YOLOv8-based deep learning model efficiently identifies multiple surface defect types, enhancing detection performance without increasing hardware complexity. Experimental validation under laboratory conditions simulating production lines demonstrates a stress measurement error of ±3 nm, dimensional accuracy of ±0.2 mm, and defect detection mAP@0.5 of 90.3%. The platform meets industrial inspection requirements and shows strong scalability and engineering potential. Future work will focus on real-time operation and exploring stress–defect coupling for intelligent quality prediction. Full article

Silicon carbide (SiC) single crystals are extensively utilized in various fields due to their exceptional properties, such as a wide bandgap and a high breakdown threshold. Nevertheless, the intrinsic high hardness of SiC creates significant challenges for contact machining. This study investigates the surface damage characteristics and underlying mechanisms involved in processing both high-purity silicon carbide (HP-SiC) and nitrogen-doped silicon carbide (N-SiC) crystals using fundamental-frequency nanosecond pulsed lasers. This study establishes a laser-induced damage threshold (LIDT) testing platform and employs the internationally standardized 1-ON-1 test method to evaluate the damage characteristics of HP-SiC and N-SiC crystals under single-pulse laser irradiation. Experimental results indicate that N-SiC crystals exhibit superior absorption characteristics and a lower LIDT compared with HP-SiC crystals. Subsequently, a defect analysis model was established to conduct a theoretical examination of defect information across various types of SiC. Under fundamental-frequency nanosecond pulsed laser irradiation, N-SiC crystals demonstrate a lower average damage threshold and a broader defect damage threshold distribution than their HP-SiC counterparts. By integrating multi-dimensional analytical methods—including photothermal weak absorption mechanisms and damage morphology analysis—the underlying damage mechanisms of the distinct SiC forms were comprehensively elucidated. Moreover, although N-SiC crystals show weaker photothermal absorption properties, they exhibit more pronounced absorption and damage response processes. These factors collectively account for the different laser damage resistances observed in the two types of silicon carbide crystals, implying that distinct processing methodologies should be employed for nanosecond pulsed laser treatment of different SiC crystals. This paper elucidates the damage characteristics of various SiC materials induced by near-infrared nanosecond pulsed lasers and explores their underlying physical mechanisms. Additionally, it provides reliable data and a comprehensive mechanistic explanation for the efficient removal of these materials in practical applications. Full article

Silicone implants are widely used in medical applications, particularly for breast augmentation and reconstruction. However, ongoing concerns regarding their long-term safety and biocompatibility necessitate comprehensive characterization. This review critically evaluates the chemical, physical, and biological testing approaches currently used to assess silicone implants, and specifically silicone breast implants, biocompatibility, and highlights the limitations of existing ISO 10993-based protocols, which often apply a one-size-fits-all model. We propose an application-specific framework to improve the relevance and precision of biocompatibility assessments. Chemical analyses, including Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy, provide essential information on polymer structure, integrity, and composition, thereby supporting quality control and market surveillance. Physical characterization methods, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle measurements, assess the surface morphology, hydrophobicity, and potential defects that may influence the host response. Mechanical testing, which evaluates properties such as tensile strength and fatigue resistance, simulates in vivo stress conditions to predict the long-term durability. Biological evaluations guided by ISO 10993 use in vitro and in vivo models to assess cytotoxicity, adhesion, inflammation, and tissue integration. However, these are often not tailored to the implant type, surface features, or duration of exposure. Emerging tools, such as organ-on-a-chip platforms and machine learning models, offer new possibilities for predictive and context-specific evaluation. We advocate a standardized, modular strategy that integrates chemical, physical, and biological testing with clinical data to bridge preclinical assessments and real-world outcomes, with a specific focus on silicone breast implants. The aim of this approach is to improve patient safety, regulatory clarity, and device innovation across the global landscape of silicone implant development. Full article

Inconel 625 is widely employed in high-temperature and corrosive environments, where the integrity of welded joints critically influences component performance. This study systematically investigates how laser beam welding (LBW) heat input governs cooling behaviour, microstructure evolution, elemental segregation, and the mechanical performance of Inconel 625 weld joints aiming to become sustainable joints. A single-spot monochromatic non-contact type infrared pyrometer is used to monitor the thermal cycles of the molten weld pool and the cooling rate and melt pool lifetime were determined based on the thermal cycle data. The impact of cooling rate and melt pool lifetime on weld geometry, microstructure, micro-segregation, and mechanical properties were thoroughly investigated. The findings revealed that the fibre laser welding produced sound, defect-free joints across all experimental heat-input conditions and the weld quality was fairly dictated by cooling rate during solidification. Reducing heat input (by using faster laser scan speeds) increased the cooling rate (1.45 × 10³ to 3.65 × 10³ °C/s), resulting in a shortened melt-pool lifetime and altered weld bead geometry from hourglass to truncated-cone profiles. Eventually, the fusion-zone microstructure transitioned from coarse cellular/columnar dendrites at high heat inputs to refined dendrites at low heat inputs. The EDS analysis revealed pronounced Nb and Mo segregation in slowly cooled welds and Laves phase formation due to insufficient time for solute redistribution and γ-Ni matrixes were consistent noted with XRD-observed peaks. The presence of the brittle Laves phase adversely affects the microhardness and tensile strength of the weld joints. Mechanical testing confirmed that decreasing heat input (in faster laser scan speeds) enhanced micro-hardness and tensile strength due to grain refinement and solute entrapment in the γ matrix. The highest joint strength (989.3 ± 10.4 MPa) and elongation (40.3 ± 1.8%) approached those of the work material, and these findings establish processing parameter–structure–property relationships for the LBW of Inconel 625. The co-relation in the present manuscript can be used in the future for process monitoring and for controlling the mechanical properties of laser welding and may provide a practical guidance for optimizing weld quality in advanced industrial applications. Full article

Reliable quality of epicutaneous patch test (PT) preparations is a prerequisite for establishing a robust diagnosis in patients with suspected allergic contact dermatitis due to delayed-type sensitization. It is difficult to identify potential quality issues in daily practice, since confirmatory methods are lacking and assessment of PT-relevance is predominantly based on patients’ history and exposure. The quality of PT products can be affected, e.g., by the properties of the active substance, an insufficient development of the PT preparation or issues during manufacturing. Resulting quality deficiencies can cause both false-negative and false-positive test results. As PT preparations are medicinal products according to Directive 2001/83/EC, they require a marketing authorization (MA) entailing assessment of quality, safety and efficacy by the competent authorities. The corresponding product dossier is the basis for MA. It is continuously updated, e.g., upon change of a source material supplier, ensuring comparability of the respective product over time. Compliance with regulatory requirements is a crucial foundation for sustainable quality to prevent product deficiencies, ensuring reliable test results in practice. Harmonization across the EU is important to ensure the widespread availability of high-quality PT products. This review presents the MA requirements of PT preparations in the EU, as well as challenges previously reported by physicians. Full article

The article presents the results of a study aimed at determining the impact of storage conditions on the gas-forming tendency of standard samples (cores) made from moulding sand using a two-component binder based on resole-type phenolic resin, cured with a dedicated ester mixture. The objective of the research was to determine the total volume of gases released as a result of contact between the cores or moulds and the high temperature of molten casting alloys, as well as the rate of gas release, which can influence the tendency for gas-related casting defects. Additionally, the influence of storage conditions on the gas-forming tendency of the samples was evaluated in terms of their environmental and occupational health impact, based on the emission of BTEX compounds (benzene, toluene, ethylbenzene, and xylenes), which serve as key indicators of the harmfulness of moulding and core sands to the surrounding environment. Full article

Background: The aim of this experimental pilot study was to evaluate the effect of pore volume and material composition on bone ingrowth into a resorbable poly-L-lactide-CaCO₃/CaP scaffold. Methods: Cylindric scaffolds of 7 mm diameter and 5 mm height and two different degrees of porosity were produced using selective laser sintering of poly-L-lactide-powder containing 24% CaCO₃ spherulites with and without surface modification with 4% CaP. Six minipigs received the four types of macroporous cylindrical scaffolds, inserted press fit into trephine defects of the tibial metaphyses, and left to heal for 4 and 13 weeks in three animals each. The specimens were evaluated using µCT for pore volume fill, and histomorphometry for bone formation and immunohistochemistry for expression of osteocalcin. Results: After 4 weeks, newly formed bone ranged from 2.73 mm² to 5.28 mm² mean total area. Mean pore volume fill varied between 12.25% and 20.35% and the average level of osteocalcin expression ranged from 2.49 mm² to 4.48 mm² mean total area. No significant differences were found between the different scaffolds. After 13 weeks, bone formation and pore fill volume had significantly increased in all scaffold groups up to a mean value of 14.79 mm² and 96.04%, respectively. Again, differences between the groups were not significant. Conclusions: The tested SLS produced scaffolds allowed for bone ingrowth, almost completely filling the pore volume after 13 weeks. Newly formed bone was in direct contact with the scaffold walls. Differences in pore volume did not account for significant differences in bone formation inside the scaffolds. The addition of CaP likewise did not lead to increased bone formation, most likely due to low availability of CaP to the biological environment. Full article

Background and Objectives: The extraction of mandibular third molars poses challenges due to their proximity to the mandibular canal and risk of inferior alveolar nerve (IAN) injury. Accurate preoperative evaluation is essential to minimize complications. This study assessed the three-dimensional positional relationship between the mandibular canal and lower third molars using cone-beam computed tomography (CBCT), aiming to identify anatomical positions associated with increased surgical risk. Materials and Methods: This retrospective study analyzed 253 CBCT scans of fully developed lower third molars. The mandibular canal position was classified as apical (Class I), buccal (Class II), lingual (Class III), or interradicular (Class IV). Contact was categorized as no contact, contact with a complete or defective white line, or canal penetration. In no-contact cases, the apex–canal distance was measured. Statistical analysis included descriptive and contingency analyses using the Chi-Square Likelihood Ratio test. Results: Class I was most common (70.8%) and presented the lowest risk, while Classes III and IV showed significantly higher frequencies of canal contact or penetration. Class II exhibited shorter distances even in no-contact cases, suggesting residual risk. Statistically significant associations were found between canal position and both contact type (p < 0.001) and apex–canal distance (p = 0.046). Conclusions: CBCT offers valuable insight into the anatomical relationship between third molars and the mandibular canal. High-risk positions—particularly lingual and interradicular—require careful assessment. Even in the absence of contact, close proximity may pose a risk and should inform surgical planning. Full article

The biological aging of titanium implants, marked by increased surface hydrophobicity and organic contamination, reduces bioactivity and delays osseointegration. A major challenge in implant dentistry is determining how to preserve surface hydrophilicity during storage, as conventional atmospheric conditions accelerate surface degradation. This pilot in vivo study aimed to evaluate ozone nanobubble water (NBW3) as a storage medium to prevent biological aging and enhance the early-stage osseointegration of glow discharge-treated titanium implants. Screw-type implants were stored in either NBW3 or atmospheric conditions and then implanted into femoral bone defects in Sprague Dawley rats. Removal torque testing, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and histological analysis of bone-to-implant contact (BIC) were performed 14 and 28 days post-implantation. At 14 days, the NBW3-stored implants demonstrated significantly higher removal torque (2.08 ± 0.12 vs. 1.37 ± 0.20 N·cm), BIC (65.74 ± 12.65% vs. 44.04 ± 14.25%), and Ca/P atomic ratio (1.20 ± 0.32 vs. 1.00 ± 0.22) than the controls. These differences were not observed at 28 days, indicating NBW3’s primary role in accelerating early osseointegration. The findings suggest that using NBW3 is a simple, effective approach to maintain implant surface bioactivity during storage, potentially improving clinical outcomes under early or immediate loading protocols. Full article

Three-dimensional/two-dimensional bilayered perovskite solar cells have recently become popular for ensuring high efficiency and promising long-term stability. The 3D/2D bilayered perovskite thin film is mainly used in regular (n-i-p)-type perovskite solar cells. In this review, our discussion also focuses on the regular kind of perovskite solar cells. In a 3D/2D bilayered perovskite thin film, the 2D perovskite layer works as a capping layer on top of the 3D perovskite thin film. The 2D capping layer heals the surface and bulk defects of the 3D perovskite thin film. The 2D layer interfaces between the 3D perovskite and hole transport layers. The 2D layer also acts as a shield against moisture and heat. This layer also inhibits ion migration between layers (3D perovskite and back contact). This review lists and investigates different organic precursors deposited as a 2D capping layer on top of the 3D perovskite thin film to explore their impact on the solar cell’s efficiency and stability. The possible challenges and remedies in growing a 2D capping layer on top of the 3D perovskite thin film are also discussed. Full article

The heat treatment residual stress of 8Cr4Mo4V steel bearings seriously affects the contact fatigue life. The micro stress concentration at the carbide interface leads to the initiation of micro cracks. Therefore, in this paper, the systematic analysis of heat treatment residual stress of 8Cr4Mo4V steel is conducted. FEA was used to analyze the residual stress of type I after heat treatment process. Based on numerical simulation and EBSD results, CPFEM was carried out to study the distribution of type II residual stress. Using high-resolution characterization results, GPA was performed to study type III residual stress caused by crystal defects. The FEA results indicate that thermal strain and phase transformation strain dominate the macroscopic stress change before and after martensitic transformation. During the first tempering process, the phase transformation leads to the release of quenching residual stress. The large stress concentration at the carbide interface is revealed by CPFEM. High-resolution characterization of coherent interface between carbide and matrix reveals that the micro residual strain at this interface is small. Through a systematic analysis of the residual stress of 8Cr4Mo4V steel, a basis is provided for modifying the macroscopic and microscopic residual stress of heat treatment to improve the bearing performance. Full article

Carbon fiber-reinforced polymer (CFRP) has become widely applied in engineering fields such as aerospace and the automotive industries. Evaluating the damage tolerance of CFRP with manufacturing defects under impact loads is crucial in ensuring the reliable service of CFRP components. In this study, four types of wrinkle defects are designed, and the effect mechanism is thoroughly discussed, focusing on the impact and compressive response. The results indicate that the wrinkle defects primarily affect the impact response via the wrinkle fibers being subjected to impact stress and wrinkle stress concentration. Notably, the first peak contact force of the specimen with a wrinkle at the 12th layer is reduced by approximately 20.00% compared to that of the specimen with a wrinkle at the third layer. Additionally, the first peak contact force of the specimen subjected to a reverse impact direction decreases by about 14.00% compared to that under a forward impact direction. The impact direction also plays a significant role in the impact response by altering the loading conditions of the wrinkle fibers during impact. Regarding the compressive performance after impact, specimens with a wrinkling layer close to the impact surface show a slight 4.80% increase in residual compressive strength, which is attributed to the greater suppression of impact damage by the wrinkle fibers. However, all other specimens with wrinkle defects demonstrate varying degrees of reduction in residual compressive strength after impact compared to the specimens without wrinkle defects. The maximum reduction is approximately 27.50% for specimens subjected to a reverse impact direction. Furthermore, the amplitude of the decrease in the residual compressive strength is mainly determined by the matrix damage and delamination that occur during impact. Full article

Wind turbine blades are made from fiberglass, whose faces are eroded due to environmental conditions. Polyurethane (PU) coatings are broadly used in several types of coatings due to their strong adhesion. However, their inferior mechanical properties limit their application on fiberglass. In this study, graphene oxide (GO) was modified through a dielectric barrier plasma (DBP) treatment at atmospheric pressure to improve the dispersion of GO in PU and increase its adhesion to fiberglass (GF) substrates, resulting in excellent adhesion properties of the PU/GO coating on fiberglass. Additionally, PU/GO coatings are crucial for preventing and protecting against erosion. The results obtained for the intensity ratio of the $I_D/I_G$ peaks observed through Raman spectroscopy exhibited that the plasma treatment increased the defects in the GO structure through covalent and non-covalent interactions with the PU. Contact angle tests and surface free energy measurements indicated the deoxygenation of the GO structure, enhancing its dispersion in the PU matrix, as observed through XRD. The plasma treatment increased the PU/GO adhesion by 27.6% after 10 min of treatment, suggesting that more defects in the GO structure were correlated with greater adhesion strength. Full article

Vision-based inspection systems are essential for quality control in manufacturing industries, and advances in artificial intelligence (AI) have significantly enhanced their accuracy. However, the high-precision requirements of products such as contact lenses demand even more robust inspection methods. This paper introduces a novel defect-adaptive hierarchical structure convolution neural network (DHS-CNN) model based on InceptionV4. The proposed model architecture reflects the manufacturing process and defect types, and we developed a custom loss function to suit this multi-output hierarchical design. Experimental results on a dataset of 2800 contact lens images revealed that the proposed model improved accuracy by 2.08% over the baseline model. These findings suggest that the defect-adaptive hierarchical structure and customized loss function offer substantial improvements in the vision-based inspection of contact lenses and may enhance AI-driven quality control processes in other manufacturing sectors. Full article

Molecular design strategies such as noncovalent conformational locks, self-assembly, and D-A molecular skeletons have been extensively used to devise efficient and stable hole transport materials. Nevertheless, most of the existing excellent examples involve only single or dual strategies, and triple strategies remain scarcely reported. Herein, we attempt to develop two quinoxaline-based hole transport materials (DQC-T and DQ-T-QD) through a triple strategy encompassing an S···N noncovalent conformational lock, D-A molecular skeletons, and self-assembly or conjugate engineering. The S···N noncovalent conformational lock formed by thiophene sulfur atoms and quinoxaline nitrogen atoms improves molecular planarity, further inducing the formation of high-quality perovskite films and enhancing hole transport ability; the asymmetric D-A molecular backbone endows the material with a larger dipole moment (μ = 5.80 D) to promote intramolecular charge transfer; and the carboxyl group, methoxy, and sulfur atom establish strong interactions between the NiO_x and perovskite layers, including self-assembly and defect passivation, which mitigates the occurrence of detrimental interfacial charge recombination and reactions. Thus, the 2-thiophenecarboxylic acid derivative DQC-T, featuring an asymmetric D-A molecular backbone, exhibits superiority in terms of good interface contact, hole extraction, and transport compared to DQ-T-QD with a D-A-π-A-D type structure. Naturally, the optimal power conversion efficiency of NiO_x/DQC-T-based p-i-n flexible perovskite solar cells is 18.12%, surpassing that of NiO_x/DQ-T-QD-based devices (16.67%) and NiO_x-based devices with or without DQC (a benzoic acid derivative without a noncovalent conformational lock) as co-HTMs (16.75% or 15.52%). Our results reflect the structure–performance relationship well, and provide a referable triple strategy for the design of new hole transport materials. Full article