Search Results (303)

This experimental work aims at the study by non-destructive and destructive testing of the mechanical and acoustical properties of cold-setting epoxy resins plasticized with amounts of plasticizer and of PMMA (Plexiglas), both belonging to the two basic categories (thermosetting and thermoplastics respectively) of polymeric materials, which usually can be modified because of polymerization rate and curing, change in temperature and frequency, by the addition of plasticizers and/or inclusions as well as due to discontinuities (defects, voids and porosity) where stress concentration exists. On the other hand, ultrasound is a mechanical, elastic wave of very high frequency, and can be used for material testing. Using ultrasounds, defects, discontinuities, and damage can be detected, and moduli can be evaluated accurately. It should be noted that the moduli determined in this way are the dynamic moduli and differ from the static ones for any material. Here, the authors focus their study on plasticized epoxy resins and PMMA and apply this NDT method to estimate mechanical properties and correlate the results with those from destructive tests. Finally, the glass-transition temperature of plasticized epoxies was also evaluated from thermal experiments to determine the effect of the plasticizer. Full article

This study systematically investigates the combined effects of three different glass fiber lengths (3, 6, and 12 mm) and three different fiber ratios (1%, 2%, and 3%) on the physical, mechanical, and microstructural properties of cement mortars. Glass fibers are known to enhance mortar performance, yet the simultaneous influence of fiber length and proportion on fresh, hardened, durability, and microstructural characteristics has not been comprehensively addressed in a single experimental framework. The parameters investigated include flow diameter, dry unit weight, water absorption, flexural and compressive strength (at 7 and 28 days), ultrasonic pulse velocity, water sorptivity, as well as SEM/EDS and XRD analyses. Results demonstrated that increasing fiber length and content decreased flow diameter and increased porosity within the mortar compositions. At a 3% fiber inclusion, dry unit weight values decreased, with the lowest value (below 2100 kg/m³) observed for the 12 mm-3% mixture. Flexural strength results highlighted the critical role of the curing process on fiber-matrix interface development. At 7 days, only 1% fiber content improved flexural strength, while higher contents reduced it. At 28 days, however, increasing fiber content generally enhanced flexural strength, particularly for 6 mm fibers, albeit at the expense of compressive strength. The capillarity test revealed that the optimal fiber proportion was 1%, with mixtures achieving compressive strengths exceeding 50 MPa and capillarity coefficients below 0.10 mm/min^0.5, while higher fiber contents led to elevated capillarity coefficients. The study concluded that, under the specific conditions tested, the most suitable fiber length is 6 mm, with a recommended fiber content of 1–2%. The 6 mm-1% combination delivered the best overall performance, achieving 60.18 MPa compressive strength, a capillarity coefficient below 0.10 mm/min^0.5, and enhanced flexural strength. While increasing fiber content improved flexural strength, it reduced compressive strength and increased the capillarity coefficient. These findings underscore the importance of using appropriate fiber proportions to optimize mortar performance and provide practical guidance for designing fiber-reinforced mortars in structural and construction applications. Full article

Background/Objectives: Stenotrophomonas maltophilia is a critical opportunistic pathogen, yet its long-term epidemiology remains underrepresented in global surveillance frameworks like WHO GLASS. We aimed to analyze its six-year epidemiological trend in a large Polish tertiary hospital. Methods: A retrospective study (2020–2025) of 399 non-duplicate isolates was conducted. Identification was performed using MALDI-TOF MS, and susceptibility was analyzed according to EUCAST breakpoints. Antibiotic consumption (DDD/100 patient-days) was correlated with isolation trends. Results: Wound/skin (36.8%) and lower respiratory tract (35.8%) samples predominated. A significant rise in respiratory isolates was observed post-2020, coinciding with peak carbapenem consumption in ICU and surgical wards. Ward-level analysis demonstrated that intensive care unit status (β = 68.9, 95% CI 46.1–91.8, p < 0.001) and carbapenem consumption (β = 0.080, 95% CI 0.004–0.156, p = 0.041) were independently associated with S. maltophilia isolation burden after adjustment for ward type (adjusted R² = 0.80). While trimethoprim–sulfamethoxazole remained highly active, levofloxacin susceptibility showed high interannual variability. Conclusions: S. maltophilia is a stable and clinically significant threat in high-intensity hospital environments. Our findings support the inclusion of this pathogen in international AMR monitoring (GLASS) and emphasize strict carbapenem stewardship to curb its emergence. Full article

Positive Leadership in Higher Education is a key process; however, its connection to the mental health and quality of life of women in leadership roles at universities has been explored only to a limited extent. This study aimed to analyze the structural relationships between positive leadership, positive mental health, and quality of life in women university leaders, and to explore the lived experiences and coping strategies that explain these associations. A mixed-methods explanatory sequential design (QUAN → qual) was employed. 45 women holding senior administrative positions in Peruvian universities completed three standardized scales. The quantitative results reveal that positive leadership significantly predicted positive mental health, which in turn strongly explained quality of life, confirming a partial mediation model. The qualitative results highlighted persistent psychosocial and structural challenges—gender bias, the glass ceiling, role overload, institutional pressure, impostor syndrome, and isolation—alongside coping strategies focused on self-care, emotional regulation, purpose-driven leadership, empowerment, sorority, and organizational transformation with a gender perspective. Positive leadership emerges as a key organizational resource that enhances women’s mental health and quality of life. Institutional cultures grounded in inclusion, care, and relational leadership are essential for sustainable and transformative women’s leadership in higher education. The WISE: Women Integrated for Sustainable Empowerment is presented as a practical action guide for positive female leadership. Full article

The growing demand for sustainable construction materials has led to significant advancements in ultra-high-performance concrete (UHPC), with a particular focus on geopolymer-based systems as an alternative to conventional cementitious binders. This review explores the latest developments in sustainable Ultra-High-Performance Geopolymer Concrete (UHPGPC) by analysing key material composition, mechanical, durability and microstructural properties. The incorporation of ground granulated blast furnace slag (GGBFS), silica fume (SF), and fly ash (FA) has demonstrated notable improvements in compressive strength, durability, and workability. Additionally, the use of activators such as sodium silicate and sodium hydroxide optimizes geopolymerization, resulting in a denser microstructure and enhanced mechanical performance. This review highlights the critical role of fibre reinforcement in UHPGPC, where steel fibres (SFs) and hybrid fibres significantly enhance compressive and tensile strength, as well as crack resistance. The inclusion of waste materials such as rice husk ash and recycled glass promotes sustainability by reducing CO₂ emissions while maintaining structural integrity. However, higher waste-glass content may adversely affect bonding due to its smooth surface texture. The findings highlight the potential of UHPGC as a high-performance, eco-friendly alternative to traditional cement-based UHPC. By integrating industrial by-products and alternative activation techniques, UHPGPC can contribute significantly to the global shift towards sustainable and low-carbon construction materials. Full article

Visual impairment affects approximately 2.2 billion people worldwide, yet existing assistive technologies remain fragmented and prohibitively expensive. This paper presents Munir, an integrated multimodal assistive system designed to enhance human–computer interaction through a combination of a mobile application and Bluetooth-enabled smart glasses. Munir leverages a hybrid machine learning architecture to provide inclusive, real-time support for daily living activities. The system integrates ten core capabilities—including face recognition, optical character recognition, and scene description—all accessible through a unified bilingual (Arabic/English) voice interface. By employing on-device processing for biometric tasks, Munir ensures user privacy and trust while maintaining high responsiveness. End-to-end system evaluation on the SCface dataset achieves a 96.69% recognition rate with 0% False Accept Rate. At an estimated first-year total cost of $806, Munir demonstrates a 4–5× cost advantage over commercial alternatives, providing a scalable and affordable multimodal solution for global digital inclusion. Full article

Objectives: The aim of the present systematic review and meta-analysis is to compare bracket adhesion failure rates between resin-modified glass ionomer cement (RMGIC) and conventional resin adhesives (CRA) during fixed orthodontic treatment (OT), based on evidence from randomized controlled trials (RCTs). Methods: The research question is “Is there a difference in bracket adhesion failure rates between RMGIC and CRA?” The study was performed in accordance with the PRISMA guidelines. A comprehensive literature search was performed across multiple databases without time or language restrictions through February 2026. Keywords were used in different combinations using Boolean operators. Hand searching was performed and disagreements were resolved via discussion. The risk of bias (RoB) and certainty of evidence (CoE) were assessed using the Cochrane risk of bias tool and Grading of Recommendations Assessment, Development and Evaluation approach, respectively. Quantitative data synthesis was conducted using a random-effects model to calculate pooled odds ratios and 95% confidence intervals. Results: Seven RCTs met the inclusion criteria. Bracket failure rates ranged from 5.95% to 15.0% for RMGIC and 3.4% to 25.0% for CRA. The pooled meta-analysis revealed no statistically significant difference in bracket failure between the two adhesive types (OR = 1.00; 95% CI: 0.60 to 1.67), although substantial statistical heterogeneity was observed (I² = 69.0%, p = 0.0065). One included trial demonstrated significantly improved retention for RMGIC when combined with a specific enamel deproteinization conditioning step prior to bonding. Three studies had a low RoB and the remaining were judged as having “some concerns”. The overall CoE was low. Conclusions: Based on the currently available randomized evidence, no statistically significant difference in bracket adhesion failure rates was observed between RMGIC and CRA during fixed OT. However, given the low CoE, substantial heterogeneity among studies, and relatively short follow-up periods, these findings should be interpreted with caution. Further well-designed randomized controlled trials with longer follow-up are needed to provide more definitive conclusions. Full article

In Türkiye, working life operates within a hybrid structure in which modern production relations and traditional gender roles intertwine. The automotive sector, in particular, where hegemonic masculinity and conservative values are reproduced, creates a breeding ground for discriminatory practices and safety issues affecting LGB employees. This study aims to analyze the psychosocial and organizational mechanisms underlying LGB individuals’ decisions to disclose or conceal their identities in the context of neoconservative social pressure and industrial masculine culture in Türkiye. Using a qualitative research design grounded in the social constructivist paradigm, semi-structured interviews were conducted with 15 LGB individuals working at different levels of the sector. Data were analyzed using reflective thematic analysis. The findings revealed themes of controlled openness, emotional labor, defense mechanisms, organizational silence, micro-solidarity, and ordinary visibility. It was determined that identity management is experienced as “strategic risk management” rather than an act of liberation, that hierarchical advancement increases the “glass closet” effect, and that employees constantly exhaust their cognitive capacity in a state of “hyper-vigilance”. In conclusion, the study examines the divergence between multinational corporations’ global inclusion policies and local practices and explores the structural factors that sustain organizational silence. Full article

Polymerization shrinkage remains a primary cause of marginal failure in posterior composite restorations, contributing to interfacial gap formation and secondary caries development. Bioactive filler technologies represent a paradigm shift, offering simultaneous stress reduction and therapeutic ion release through engineered matrix–filler interactions. This narrative review synthesizes current evidence on how bioactive glass (including 45S5), amorphous calcium phosphate, and surface pre-reacted glass-ionomer fillers modulate polymerization shrinkage dynamics and mechanical performance in bulk-fill systems. These systems exhibit distinct mechanisms of bioactivity, with bioactive glass (45S5) promoting ion release and apatite formation, amorphous calcium phosphate (ACP) enabling rapid calcium phosphate ion delivery for remineralization, and surface pre-reacted glass-ionomer (S-PRG) fillers providing sustained multi-ion release with buffering and antibacterial potential. A comprehensive literature search was conducted in PubMed/MEDLINE, Scopus, and Web of Science for studies published up to June 2025, including experimental investigations and reviews assessing bioactive filler integration, with studies selected based on predefined inclusion and exclusion criteria focusing on relevance and reported outcomes. The available evidence indicates that optimized bioactive formulations reduce shrinkage stress by approximately 25–40%, decreasing from 35–40 MPa in conventional systems to 22–32 MPa in bioactive bulk-fill composites while maintaining flexural strength above 100 MPa and elastic modulus within clinically acceptable ranges (11–13 GPa). However, substantial heterogeneity in filler chemistry, loading protocols, and testing methodologies limits cross-study comparisons. This variability also reflects differences in testing conditions, material compositions, and evaluation protocols across studies. Full article

Published laboratory data on soil stabilisation are abundant, yet they remain fragmented across studies and are often difficult to reuse because of inconsistent reporting formats, heterogeneous testing conditions, and incomplete metadata. This article presents a curated experimental dataset compiled from 20 published studies on fine-grained soils, comprising 560 records, including 397 unconfined compressive strength (UCS) results and 163 California Bearing Ratio (CBR) results. The dataset is defined by the inclusion of laboratory studies designed around biopolymer-based two-additive stabilisation frameworks, while intentionally retaining untreated and single-additive comparator records reported within the same experimental programmes. This design is a key distinguishing feature of the dataset because it enables analysis of baseline soil behaviour, isolated additive effects, and combined-additive responses within a traceable study context. Across the included studies, the treatment systems cover a wide range of biopolymer- and lignin-related materials, including xanthan gum, guar gum, chitosan, sodium lignosulfonate, and electrolyte lignin stabiliser, together with complementary additives such as cement, lime, fly ash, ground granulated blast-furnace slag, rice husk ash, glass powder, concrete waste, nano-additives, and natural or synthetic fibres. In addition to UCS and CBR outcomes, the dataset preserves key contextual variables required for meaningful secondary reuse, including soil classification, grain-size fractions, Atterberg limits, compaction properties, curing duration, additive identities and dosages, and source-level traceability. The data are distributed as a structured Excel workbook comprising two cleaned outcome-specific sheets (CBR_clean and UCS_clean) and four supporting documentation sheets (StudyInventory, DataDictionary, VocabularyMap, and QC_Log). Record-level identifiers, DOI-linked source fields, inferred-curing flags, and qualified outcome descriptors are retained to support auditability, selective filtering, and reproducible reuse. The resulting dataset provides a practical foundation for comparative assessment of stabilisation strategies, pavement and subgrade engineering studies, meta-analysis, and machine learning applications in geotechnical engineering. Full article

This study considers the potential of utilizing waste glass powder as a sustainable additive to improve the characteristics of clay subgrade soils. A comprehensive experimental program was designed, wherein a selected clay soil was amended with four distinct contents of glass powder that were finely ground: 0%, 3%, 6%, and 9% by weight. The primary objective was to evaluate the resultant improvements in soil strength and the enhanced interfacial bond between the treated subgrade and an overlying Type B granular subbase layer, which was further reinforced with an SS2 Geogrid. To characterize these effects, a suite of laboratory tests was performed, including the Modified Proctor Test, Atterberg Limits Test, California Bearing Ratio (CBR) test, and a large-scale direct shear test. A specially made large-scale instrument for direct shear was employed for the interface testing. The results demonstrate a clear positive correlation between the proportion of glass powder and the improvement in geotechnical properties. The most significant enhancement was observed at the 9% inclusion rate, which yielded a 6.6% increase in the maximum dry density and a substantial 49% improvement in the CBR value. Concurrently, this optimal mix design resulted in a 14% reduction in optimum moisture content, alongside notable decreases in the swelling and plasticity indices by 33% and 39%, respectively, confirming the efficacy of glass powder in stabilizing the clay subgrade. Full article

This review summarizes the base materials, joining methods, filler materials, and principal technical challenges in endoscope joining fabrication, and proposes practical strategies to improve joint reliability under clinical constraints. We conducted a comprehensive search in multiple databases, including Web of Science, Google Scholar, patent databases, Scopus databases, and Medline (via PubMed), for articles on the joining for precision endoscope fabrication, covering the period from 1950 to 2026. We employed the combinations of keywords, “endoscopy”, “minimally invasive surgery”, “welding”, “joining”, “sealing”, “soldering”, “bonding”, and “brazing”. Approximately 500 references were retrieved. After excluding duplicates and irrelevant studies, 158 publications met the inclusion criteria. Data on base materials, joining, processes, filler materials, and technical issues related to sterilization, corrosion, and microstructural evolution were extracted and analyzed. Endoscopes are multi-material systems, involving metallic biomaterials (stainless steels (SSs), titanium alloys, nickel-based alloys, etc.), optical functional materials (glass, sapphire, quartz, etc.), engineering plastics, ceramics, composite materials, and coatings. Joining, sealing, and functional integration have been achieved via adhesive bonding, laser soldering, laser brazing, wave soldering, reflow soldering, fusion welding, and other joining techniques. The main challenges include how to reliably join highly mismatched dissimilar materials, how to fabricate low-residual-stress joints, and how to increase the long-term resistance to sterilization-induced degradation and thermal aging over repeated 100–200 °C thermal cycles. Conventional joining techniques struggle to balance mechanical integrity, joint hermeticity, and long-term stability under such harsh cyclic conditions. The resulting joints may suffer surface yellowing, interfacial debonding, microcracking, delamination, or progressive property degradation during service. We propose the following three strategies to achieve reliable, low-residual-stress, and sterilization-resistant joining of dissimilar materials for endoscopes: (1) A synergistic design that combines thin-film engineering (including evaporation, sputtering, and electroplating) with silver anti-oxidation layers is proposed to reduce residual stresses and to enhance the joint hermeticity. (2) To develop principles for the selection of multi-joining processes to achieve the multi-material integration and functional assembly of dissimilar material components. (3) To develop the laser-based joining methods (fusion, brazing, or braze-welding) for precision control of heat input, bonding quality, and the least damage to the heat-sensitive components. Full article

The study focuses on the infrared nondestructive detection of inclusion-type internal defects in glass-fiber-reinforced plastic (GFRP) wind turbine blade specimens, which were designed to simulate the laminated material structure and typical hidden defects of in-service blades. To address the difficulty of detecting internal defects in in-service wind turbine blades, this paper establishes an active thermal imaging defect detection and recognition system using a halogen lamp as the infrared thermal excitation source and a high-resolution thermal imaging camera as the detection component. To improve the recognition of defect contour information in infrared images, a method combining bidimensional filtering empirical mode decomposition (BFEMD), Gaussian filtering, and Otsu threshold segmentation is proposed. The BFEMD procedure decomposes the infrared image into bidimensional intrinsic mode function components and residual components, Gaussian filtering suppresses noise in the selected components, and Otsu threshold segmentation extracts the defect contours. Experimental results show that the combined algorithm can enhance defect targets in infrared images, improve visibility and contour integrity, and provide a higher detection rate for wind turbine blade defects under different defect depths and materials. Full article

This paper investigates women’s movements in German-speaking Europe that operate at the intersection of academic theology and activism, challenging the assumption that gender parity within theological institutions has been achieved. Despite broader European progress toward gender equality, theological faculties continue to exhibit structural disparities, including women’s underrepresentation in senior positions and persistent obstacles such as the “leaky pipeline,” the “glass ceiling,” and restrictive ecclesial procedures like the Nihil Obstat. These dynamics intensify the vulnerability of women theologians, particularly those advocating for gender justice within Church structures that do not consistently recognize women as full participants. The study also highlights the vulnerability experienced by women theologians who advocate for gender equality within ecclesial institutions that do not consistently recognize women as full participants. Interdisciplinary dialogue between theology and the social sciences is often met with suspicion, as religion is frequently portrayed as a source of division rather than a catalyst for transformation. Moreover, extremist and fundamentalist movements instrumentalize gender issues, polarizing European societies and suppressing interfaith initiatives that promote justice, care, and cooperation. The paper argues for transversal, intersectional, and inclusive approaches that bridge academic and activist networks. By fostering collaboration, critical reflection, and shared praxis, these movements reimagine the role of women in both Church and society, offering transformative models grounded in justice, dignity, and equality. Full article

Background/Objectives: Bioceramic scaffolds with complex geometries and customized mechanical and biological properties can now be produced via 3D printing, revolutionizing dental and maxillofacial tissue engineering. This review discusses the recent progress in 3D printing technologies applied to bioceramic scaffolds for dental and maxillofacial reconstruction. Methods: A comprehensive literature search was conducted across major electronic databases, including Scopus, PubMed, ScienceDirect, and Web of Science. Peer-reviewed articles published between 2015 and 2026 were considered for inclusion. Several 3D printing methods can be used to create bioceramic or composite scaffolds for the regeneration of dental, oral, or maxillofacial tissues. Results: Additive manufacturing enables customization of bioceramic scaffolds. This report emphasizes the osteoconductive properties, biodegradability, and compatibility of calcium phosphate, bioactive glass, and calcium silicate ceramics. Conclusions: This review helps to determine how 3D-printed bioceramics can be optimized for dental and maxillofacial applications tailored to specific patients. Full article