Search Results (92)

This study investigates the screw withdrawal resistance (SWR) of hollow wood–plastic composite (WPC) door frames, which serve as moisture-resistant alternatives to traditional wood-based materials. The tested WPC, characterised by a density of 1.33 g/cm³ and a polymer-bound lignocellulosic filler, exhibits superior dimensional stability and low water absorption—under 4% after 24 h of immersion. The research focuses on how the unique chambered geometry of these industrial profiles affects the anchoring of 20 mm conical wood screws used to mount essential fittings such as hinges and lock catches. The SWR was determined using a universal testing machine in accordance with the modified EN 320 standards. Results indicate that the installation location within the profile significantly dictates load-bearing capacity: the band profile (lock catch) achieved an average SWR of 525.65 N, while the beam profile (hinge) averaged only 275.25 N. This performance gap arises because screws anchor only into internal “ribs” rather than the full material depth. Since these values are considerably lower than those of traditional particleboard (~1364–1775 N), the study highlights a critical need to optimise screw dimensions to ensure the structural stability and safety of hollow WPC door systems. Full article

Bivalves possess a diverse array of photoreceptive organs that are significant for their evolutionary success and systematic classification. Giant clams are the largest bivalve mollusks, with mantle tissue permanently extended in nature to maintain symbiosis with zooxanthellae and perceive environmental cues. Eyes serve as critical sensory organs for these organisms, yet the structural and functional characteristics of tridacnine eyes remain inadequately understood. This study systematically investigated the ocular traits and visual resolution of three ecologically distinct giant clam species (Tridacna crocea, T. squamosa, T. maxima) using morphometric analysis, hematoxylin-eosin (HE) staining, transmission electron microscopy (TEM), and grating stimulation assays. Significant interspecific differences were observed in eye count, diameter, and pupil-to-eye ratio (PER): T. maxima exhibited the highest mean eye count (221 ± 8), T. squamosa the largest mean eye diameter (0.490 ± 0.082 mm), and T. crocea the highest mean PER (0.363 ± 0.041). Eyes were numerically symmetric on the left and right mantles but positionally asymmetric, showing random distribution patterns along the mantle margin without fixed corresponding locations across species. All three species possessed typical pinhole eyes lacking lenses and retinas, primarily composed of filler cells, receptor cells, and sparse neurons, with symbiotic zooxanthellae distributed in the surrounding mantle tissue. Grating stimulation assays revealed resolvable stripe periods of 5.82–11.64° (T. crocea), 8.62–13.16° (T. squamosa), and 10.15–12.26° (T. maxima), confirming T. crocea as the species with the highest visual resolution. These ocular variations are inferred to reflect adaptive evolution driven by ecological niches and habitat-specific factors (water depth or light intensity), while the simplified pinhole morphology is consistent with their sedentary lifestyle and metabolic dependence on symbiotic zooxanthellae. These ocular variations provide potential morphological markers for the systematic classification of Tridacninae and offer valuable insights for researchers studying the evolutionary plasticity of bivalve visual systems. Full article

Current electrical self-sensing methods for composite structural health monitoring face significant limitations. Firstly, they often require complicated electrode layouts. Secondly, accurately determining both the location and amplitude of external loads remains a significant challenge. In this study, a deep learning-based self-sensing method is developed to identify the location and amplitude of external mechanical loads in resin-based conductive composites with a simple electrode layout. First, conductive filler-filled resin composites are prepared, and three-dimensional conductive networks are constructed within them. Subsequently, four electrodes are installed at the edges of the composite plate, and boundary electrical resistance responses are collected when applying mechanical loads at various positions on the composite plate. Finally, a residual learning-based CNN model is proposed for the accurate localization and amplitude identification of the applied loads. Research results demonstrate that the trained CNN model can accurately and effectively determine both the load amplitude and position. The obtained localization error and amplitude error are 0.91 mm and 0.13 N, respectively, surpassing the reported error values in previous studies. The research presented here opens a new avenue for achieving highly accurate and efficient prediction of load location and amplitude, which can be widely applied in composite structural health monitoring. Full article

The integration of electrically conductive functionalities into polymer components via additive manufacturing has gained increasing relevance across fields such as sensing, energy storage, and structural electronics. Achieving reliable performance in such applications requires a deeper understanding of how processing conditions affect the internal structure of conductive thermoplastic composites—particularly the orientation and distribution of anisotropic fillers. This study analyzes a PLA-based composite containing carbon nanotubes, carbon black, and graphite flakes to evaluate the influence of extrusion temperature on electrical resistivity and micromechanical properties. To complement scanning electron microscopy, a novel micromechanical mapping approach based on nanoindentation was applied, enabling spatially resolved analysis of local stiffness and hardness. Results show that increasing extrusion temperature improves filler dispersion and alignment, enhancing conductivity and mechanical homogeneity—up to a threshold of 210 °C. Even small temperature changes significantly affect particle orientation and distribution. Unlike global resistivity measurements, the combined use of nanoindentation and microscopic imaging reveals location-specific structural phenomena and filler behavior within the matrix. This newly established method provides high-resolution insight into internal composite architecture and offers a robust foundation for optimizing process-structure-property relationships in conductive polymer systems. Full article

During active brazing of alumina ceramics, active elements react with the ceramic to form a reaction layer, which has significant influence on the mechanical property of the brazed joint. However, the composition and formation mechanism of this layer remain unclear among researchers. To fill this gap, different brazing temperatures (900–1100 °C) and heating rates (2.5 °C/min and 10 °C/min) were used to braze 95% Al₂O₃ ceramics and a Kovar 4J34 alloy using a Ag-Cu-2Ti active brazing filler, and the microstructure and mechanical properties of the joints were investigated. The results show that the joint could be divided into five layers: Al₂O₃, ceramic-side reaction layer, filler layer, Kovar-side reaction layer, and Kovar. The ceramic-side reaction layer could be further divided into a Ti-O-rich layer and an intermetallics (IMC)-rich layer, and the Kovar-side reaction layer consists of TiFe₂ particles, Ag-Cu eutectic, and the remaining Kovar. A belt-like TiFe₂+TiNi₃ IMC could be found in the filler layer. Increasing the brazing temperature enlarged the belt-like TiFe₂+TiNi₃ IMC in the filler layer and increased the thickness of the IMC-rich layer in the ceramic-side reaction layer, but had no significant effect on the thickness of the Ti-O-rich layer in the ceramic-side reaction layer. A lower heating rate (2.5 °C/min) was found to suppress the formation of the IMC-rich layer and shift the fracture location in shear tests from the ceramic-side reaction layer to the filler layer, indicating that the strength of the ceramic-side reaction layer was enhanced by controlling the formation of the IMC-rich layer. A maximum shear strength of 170 ± 61 MPa was obtained at a heating rate of 2.5 °C/min and a brazing temperature of 940 °C. Full article

The behavior of a cantilever beam equipped with a particle damper, subjected to impact loads at various locations, was investigated using the discrete element method (DEM). The flexible cantilever steel beam and the particle damper attached to the beam’s tip were modeled with bonded particles through DEM. Computational simulations were conducted to explore the influence of different particle damper porosities and positions along the beam’s length. It was observed that reducing the particle damper’s porosity decreases the beam’s displacement. The impact force was significantly influenced by the porosity, where having lower porosities resulted in higher impact forces. In addition, the time intervals between sub-impacts were also affected by the damper’s porosity, showing a reduction as the porosity of the damper decreases. The unique type of particle damper used in this study contained sand grains as fillers and was capable of pressurizing the sand within its housing. This feature was utilized to investigate the effect of different initial pressures on the beam’s response. It was revealed that an increase in initial pressure reduces the beam’s displacement. Based on the results obtained, the optimal location for the particle damper was determined to be at the point where displacement reduction is required. Full article

Deep margin elevation (DME) is a widely adopted technique for managing subgingival cervical proximal margins by repositioning them to a supragingival location. This approach enhances access, visibility, and control in these anatomically challenging areas. This narrative review aimed to evaluate current evidence on the indications, materials, clinical protocols, and outcomes of DME. A structured search was conducted in PubMed, the Cochrane Library and Scopus up to February 2025, using keywords such as “deep margin elevation”, “proximal box elevation” and “subgingival margin.” Clinical studies, in vitro investigations, relevant reviews and reports in English were included. A total of 59 articles were selected based on eligibility criteria. The hypothesis was that DME can serve as a reliable alternative to surgical crown lengthening in appropriate cases. A variety of materials have been investigated for use as the intermediate layer, with composite resins of varying viscosities and filler compositions being preferred due to their favorable long-term mechanical properties. DME may reduce the need for surgical intervention while maintaining periodontal health; however further randomized clinical trials are needed to clarify the material selection, establish long-term outcomes, and standardize clinical protocols. Understanding the indications, limitations, and protocol of DME is critical for achieving biologically sound and predictably functional restorations. Full article

Background/Objectives: Anatomical knowledge of the arterial supply to the lower face is critical to prevent unnecessary harm to patients seeking cosmetic procedures, particularly lower lip dermal filler injections. Our study sought to characterize the prominent vascular structures of the lower lip: inferior labial (ILA), labiomental (LMA) and mental (MA) arteries. Methods: Forty-eight hemiface specimens from 30 formalin-embalmed donors were utilized in this study. Dissection was performed of the LMA, ILA, and MA to determine their diameter, branching pattern for characterization, and to assess their supply to the lip distally. Results: The ILA (mean diameter, 1.5 ± 0.49 mm) was found to be prevalent in 90% of sampled donors. The LMA (1.2 ± 0.53 mm) was found in 75% of donors. All 48 hemifaces were found to have a MA (1.6 ± 0.51 mm). 88% of ILAs, 43% of LMAs, and 96% of MAs were identified as directly supplying the lower lip. Mean location of the MA as it supplied the lower lip was determined to be (−17 mm, −8.2 mm) and (20 mm, −8.1 mm) in the left and right hemifaces, respectively. F-Test for variance found no significant differences amongst the horizontal (p = 0.82) and vertical distances (p = 0.41) bilaterally. Conclusions: Our findings demonstrate the high variability in vascular supply of the lower lip, suggesting the need for high-resolution ultrasound guidance and the integration of anatomical training within injection courses for the safe injection of dermal fillers. Full article

In this paper, a systematical study on the influence of strengthening parameters on the flexural performance of RC beams using the NSM application was carried out. Experimental results consist of two reference beams and 25 beams divided into two groups using NSM systems with various embedded bars and strengthening configurations were presented. Additionally, theoretical analysis was conducted to enrich the research on the parameters affecting the strength and failure mode of the beams. The accuracy of the theoretical formulas has been verified through experimental results, and the average value of the ratio between the theoretical and experimental values is approximately 0.9. Results indicated that NSM technology is an effective approach for strengthening RC structures. Compared with the control specimens, the maximum load-bearing capacity of the beams with the NSM system experiences a remarkable enhancement of nearly 140%. The flexural behavior of the beams strengthened by the NSM system are closely related to the material properties (steel bar, NSM bars, concrete, and filler), location of the cutoff points, external confinement, and prestress level. The NSM bars characterized by high strength and high elasticity prove to be far more advantageous in enhancing the strength of the strengthened specimens. The research findings can provide theoretical support for the practical engineering applications of the NSM technology in strengthening reinforced concrete structures. Full article

Background: Curettage represents a reliable therapeutic option for large-sized benign and locally aggressive bone tumors. In cases of impending fractures, internal fixation with plates and screws can be necessary to stabilize the treated bone after curettage. Metal plates have been the only fixation devices available on the market for decades, but Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) now represents an alternative in orthopedic oncology. Methods: We reviewed our patients with benign or locally aggressive bone tumors treated with curettage and fixation with CFR-PEEK plates. Plate length and curettage technique were chosen considering the characteristics of each lesion. We recorded the size and location of the lesions, adjuvant treatments and fillers used after curettage, complications, and local recurrences. Postoperative functionality was assessed using the MSTS score. Results: Forty cases were included in our study. The tumors were located in the distal femur (19 cases), femur shaft (1), humerus (17), or proximal tibia (3). Local adjuvants were used in 20 cases. Cavities were filled with bone allografts in 30 cases and cement in 10 cases. Only four cases suffered postoperative complications, and two developed local recurrences. The mean postoperative follow-up was 29.2 months. The mean postoperative upper and lower limb MSTS was 28.0 and 26.7, respectively. Conclusions: After an accurate curettage and an adequate filling of the resulting bone gap, CFR-PEEK plates can provide good mechanical resistance, and their radio-transparency can ease the early diagnosis of local recurrences. CFR-PEEK plates should be considered in selected cases, in a personalized surgical approach. Full article

The inner ear and/or lateral line are responsible for hearing and balance of vertebrate. The otic sensory hair cells (HCs) employ cilium organelles, namely stereocilia and/or kinocilia, to mediate mechanical stimuli to electrical signal transition. Tektins (Tekts) are known as the cilium microtubule stabilizer and inner-space filler, and four Tekt(1-4)-encoding genes are identified in zebrafish HCs, but the subcellular location of Tekts in HCs remains unknown. In the present study, we first found that tekt3 is expressed in the inner ear and lateral line neuromast. Antibody staining revealed that Tekt3 is present in neuromast and utricular HCs. It is absent in the saccule, the authentic hearing end-organ of zebrafish and the crista of semi-circular canals. Furthermore, Tekt3 were enriched at the apical side of neuromast and utricular HCs, mainly in the cytosol. Similar subcellular distribution of Tekt3 was also evident in the outer HCs of mature mouse cochlea, which are not directly linked to the hearing sense. However, only neuromast HCs exerted morphological defect of kinocilia in tekt3 mutant. The disrupted or distorted HC kinocilia of mutant neuromast ultimately resulted in slower vital dye intake, delayed HC regeneration after neomycin treatment, and reduced startle response to vibration stimulation. All functional defects of tekt3 mutant were largely rescued by wild-type tekt3 mRNA. Our study thus suggests that zebrafish Tekt3 maintains the integrity and function of neuromast kinocilia to against surrounding and persistent low-frequency noises, perhaps via the intracellular distribution of Tekt3. Nevertheless, TEKT3/Tekt3 could be used to clarify HC sub-types in both zebrafish and mice, to highlight the non-hearing HCs. Full article

This work presents the results of a study on the influence of fillers on the neutron absorption capacity of materials made from ultra-high molecular weight polyethylene (UHMWPE). Composite materials based on UHMWPE were obtained using gas-flame technology with the addition of powdered UHMWPE fillers (H₃BO₃, WC, and PbO). A radiation cassette has been developed and constructed for conducting studies on the neutron absorption capacity of the material, allowing for the placement of a sample with activation indicators. Samples of UHMWPE with fillers were irradiated at different doses on the unique research reactor IVG-1M, located at the National Nuclear Center of the Republic of Kazakhstan in the city of Kurchatov. The reaction rate of ⁶³Cu (n, g), ⁶⁴Cu and ⁵⁸Ni (n, p)⁵⁸Co on activation indicators and neutron flux density at the sample location were determined. Neutron-physical and thermal-physical calculations were performed in order to determine their characteristics. The structure and phase state of UHMWPE with fillers were studied before and after irradiation. Full article

This study investigates the compressive behavior of aluminum honeycombs partially filled with expanded polystyrene (EPS) foam, emphasizing the effects of filler area fractions and vertex contact locations on energy absorption and crush characteristics. Axial quasi-static compression tests evaluated energy absorption, mean crush force, specific energy absorption, and crush force efficiency. Results revealed that partially filled honeycombs significantly enhance energy absorption and mean crush force compared to their unfilled counterparts. However, higher filler area fractions increased mass, reducing specific energy absorption. Circular fillers exhibited lower energy absorption than hexagonal fillers due to their larger contact radius, which reduces stress concentration. The interaction between cell walls and fillers influenced densification strain, with wall–midpoint vertex contacts increasing peak force by reinforcing walls, while corner contacts reduced peak force but improved crush force efficiency. These findings underscore the potential of optimized, partially filled honeycombs for lightweight, energy-absorbing applications, particularly in automotive engineering. Full article

Background: The evaluation of evidence, which frequently takes the form of scientific evidence, necessitates the input of experts in relevant fields. The results are presented as expert opinions or expert evaluations, which are generally accepted as a reliable representation of the facts. A further issue that remains unresolved though is the process of evaluating the expertise and knowledge of an expert in the first instance. In general, earned certificates, grades and other objective criteria are typically regarded as representative documentation to substantiate an expert status. However, there is a possibility that these may not always be sufficiently representative. Objectives: The goal of the present study was to provide evidence that the neural processing of law-relevant and law-irrelevant terms varies significantly between participants who have received training in the field of law (experts) and those who have not (novices). Methods: To this end, changes in brain activity were recorded via electroencephalography (EEG) during visual presentations of terms belonging to five different categories (fake right, democracy, filler word, basic right and rule of law). Event-related potentials (ERPs) were subsequently averaged for each category and subjected to statistical analysis. Results: The results clearly demonstrate that participants trained in law processed fake rights and filler words in a similar manner. Furthermore, both of these conditions elicited different levels of brain activity compared to all law-relevant terms. This was not the case in participants who had not received legal training. The brains of untrained participants processed all five term categories in a strikingly similar manner. In light of prior knowledge regarding language processing, the primary focus was on two distinct electrode locations: one in the left posterior region, and the other in the left frontal region. In both locations, the most prominent differences in brain activity elicited by the aforementioned term categories in law-trained participants occurred approximately 450 milliseconds after stimulus onset. The results were further corroborated by a repeated-measures ANOVA and subsequent t-tests, which also demonstrated the absence of this effect in law-untrained participants. Conclusions: The findings of this study provide empirical evidence that brain activity measurements, in particular ERPs, can be used to distinguish between experts trained in a specific field of expertise and novices in that field. Such findings have the potential to facilitate objective assessments of expertise, enabling comparisons between experts and novices that extend beyond traditional criteria such as qualifications and experience. Instead, individuals can be evaluated based on their cognitive processes, as observed through brain activity. Full article

Multipolar bonded magnets based on a thermoset matrix provide the opportunity to expand the applications of bonded magnets, especially within the drive technology industry, in terms of the high thermal and chemical resistance, along with a higher utilisation of the magnetic potential. To realize the application of polymer bonded magnets based on thermosets within the drive technology industry, general design parameters in terms of the material, the process parameters, and the tool concept are needed. These allow for a fundamental realization of multipolar bonded magnets with complex geometries in drive technologies, based on thermosets as the matrix material. This paper investigates the impact of the material (matrix material and filler grade), the process conditions (holding pressure (p_h) and heating time (t_h)), and the tool concept (gating position and system, sleeve material, pole division, and sample thickness) on the magnetic properties in terms of the remanence (B_R) and the deviation (Δs) of the pole division, as well as the orientation of the fillers in the middle of the pole and at the pole pitch. For each parameter, an optimised value is derived. In the majority of the cases, this value is equal in terms of the magnetic properties and the orientation. In terms of the sleeve material and the sample thickness, the ideal value differs between the two criteria. Therefore, an optimised value for each criterion, as well as an overall value, is defined. In terms of the material, PF, along with a high filler grade; in terms of the process conditions, a high holding pressure (p_h) and a low heating time (t_h); and in terms of the tool concept, a two-pinpoint gating system, located in the middle of the pole, a Ferro-Titanit-Cromoni sleeve material, a high pole division, as well as small sample thickness, should be selected to improve the properties of polymer bonded magnets based on thermosets. Full article