Search Results (1,731)

Background: Microplastics (MPs; <5 mm) are pervasive contaminants that can compromise freshwater wetland integrity and wildlife health, yet field evidence from inland systems and non-invasive biomonitoring remains limited. To address this gap, we provide a non-invasive, feces-based baseline for a key wintering waterbird in an inland soda-lake wetland of Türkiye, supported by polymer confirmation. Methods: We evaluated MP occurrence in fecal deposits of the Greylag Goose (Anser anser), a key wintering waterbird at Lake Erçek (Eastern Anatolia, Türkiye), using non-invasive sampling across five periods (October 2024–February 2025). We collected 400 fecal deposits and pooled them into five time-specific composite samples. Accordingly, temporal comparisons are presented descriptively at the composite (period) level rather than as individual-level statistical inference and quantified suspected MPs by type, shape, size, and color; a representative subset (>300 µm; ~20%) was polymer-confirmed by FT-IR, and particle surfaces were examined by SEM–EDX. Results: In total, 959 suspected MP items were recovered, corresponding to an estimated 1.75–2.85 items per fecal deposit (composite-derived; mean 2.40). MP counts peaked in late autumn–early winter (Time 2–Time 3) and declined toward late winter (Time 5). Fibers predominated (37.22%), followed by fragments (30.55%) and pellets (18.77%); the most frequent size class was 100–300 µm (30.25%), and white/transparent particles were most common (38.52%). FT-IR identified polystyrene, polyethylene, and polyvinyl chloride, while SEM–EDX indicated weathered polymeric surfaces. Conclusions: These findings provide baseline evidence of MP exposure in an inland wetland waterbird and support feces-based monitoring for comparative assessments. Full article

Electrical curing is a viable alternative to traditional thermal curing for geopolymer materials due to its capability for rapid and internal geopolymerization. In this research, reinforced geopolymer-based composite beams were successfully fabricated at a macroscale using a binary system of fly ash (FA) and granulated blast furnace slag (GBFS). The mixture was activated with a solution of sodium silicate (Na₂SiO₃) and sodium hydroxide (NaOH) with a fixed molar ratio of 2:1 for both, and aggregate-to-binder and activator-to-binder (A/B) ratios of 2.5 and 0.7, respectively. To ensure electrical conductivity, individual fiber systems were employed, including carbon fiber (CF), steel fiber (SF), and waste wire erosion (WWE), each incorporated at a dosage of 0.5 vol.% of the total mix volume. In addition, carbon black (CB) was introduced as a conductive filler at a constant dosage of 2.0 vol.% of the binder content in selected specimens. Each beam specimen contained only one type of conductive reinforcement or filler. A total of twelve reinforced geopolymer-based composite beams with a 150 mm square section and a span of 1300 mm, with a clear span of 1200 mm, were successfully cast and reinforced based on reinforced concrete beam designs and standards, with a dominant goal of enhancing beam behavior under flexure. The beams were cured in ambient curing conditions, or using thermal curing at 80 °C for 24 h, and using electrical curing from the fresh states with a fixed voltage of 25 V. Notwithstanding a common beam size and reinforcement pattern, distinct curing methods significantly influenced beam structure properties. Peak loads were between 20.8 and 31.5 kN, initial stiffness between 1.75 and 6.09 kN/mm, and total energy absorption between 690 and 1550 kN/mm, with a post-peak energy component of between 0.12 and 0.55. Displacement-based ductility measures spanned from 3.2 to 8.1 units with a distinct improvement in electrical curing regimes, especially in the SF-reinforced specimens; this indicates that electrical curing in reinforced geopolymer composite materials works as a governing mechanism in performance rather than simply a method for enhancing the strength of materials. Full article

In the present study, glass/ceramic hybrid fibers were chosen as a paper matrix, which effectively balance toughness and high-temperature resistance for soot combustion applications. In order to address the issue of unevenness in the performance of paper-type catalysts caused by the differences in the dispersion behavior of glass fibers and ceramic fibers in water, a facile foam-forming technology was proposed. The obtained glass fiber/mullite composite paper with various mass ratios (1:1, 2:1, 3:1, 4:1, and 5:1) exhibit high evenness, and better high-temperature resistance than the pure glass fibers. After impregnating K-Mn active ingredients, 15K5Mn-GFF-3G1C (GF/CF = 3:1) demonstrates high tensile strength, excellent catalytic activity (T50 = 388 °C), reusability (five cycles), and high-temperature stability (800 °C, 12 h). Full article

Circulation is one of the most prevalent and severe complications during the drilling and completion of deep and ultra-deep wells, especially in fractured and karstic formations. In regions such as the Sichuan Basin, bottom-hole temperatures exceeding 200 °C, limited formation strength, and frequent lithological alternations significantly reduce the effectiveness of conventional granular materials under high-temperature and long open-hole conditions. Bridging-type plugging systems based on particle gradation or principles often exhibit low success rates due to fiber softening, rubber aging, and erosion-induced deterioration of the sealing structure. In this study, a high-temperature-resistant bridging composite system was developed to meet the extreme conditions in deep and ultra-deep wells. By incorporating temperature-resistant bridging particles and flexible reinforcing components, the slurry establishes a synergistic “bridging–filling–densification” sealing mechanism. Meanwhile, the combined use of retarders, fluid-loss reducers, and rheology modifiers ensures stable pumpability and adequate curing densification at 200 °C. Overall, the results provide new insights and experimental evidence for the design of high-temperature cement-based plugging materials, offering a promising approach for improving loss-control effectiveness and wellbore strengthening in complex intervals. Full article

Water-lubricated bearings are critical components in marine propulsion systems, necessitating materials with exceptional tribological properties to ensure reliability. Filament-winding technology is an effective molding method for enhancing the comprehensive properties of polymers, and the selection of fiber materials has a significant impact on the performance of polymers. In this study, three types of polyurethane (PU) matrix filament-winding composites were fabricated via filament-winding technology. Under water-lubricated conditions, a friction test (disk-to-disk) with a duration of 2 h was performed, followed by systematic observations of the resultant wear behavior. The results indicate that aramid fibers exhibited the superior reinforcing effect on the PU matrix, effectively suppressing wear while enhancing mechanical properties. Specifically, under the conditions of 0.5 MPa-250 r/min (0.314 m/s), the minimum friction coefficient of the aramid fiber-wound composite material was 0.093, which was 57.73% lower than that of pure polyurethane. Under the conditions of 0.7 MPa-50 r/min (0.0628 m/s), the wear mass of the sample was limited to only 1.5 mg, which was 12% lower than that of polyurethane. This research can provide a practical reference for the application of filament-wound composite materials in water-lubricated bearings. Full article

Vehicle crush boxes are one of the safety elements used in vehicles to minimize damage that may occur during an accident. The task of crush boxes is to absorb the energy which is generated during an accident. In this study, peak force, energy absorption and specific energy absorption values of cylindrical composite crush boxes, to which 0.25% and 0.50% graphene was added, were experimentally investigated with hydrothermal aging. The composite crush boxes were produced with vacuum infusion method. Glass, aramid and carbon fibers and their hybridizations were used as fibers. During hybridization, the winding order of the fibers was changed from inside to outside. The parameters for hydrothermal aging were selected as 500 h and 1000 h at 60 °C. The highest energy absorption value was obtained in the carbon fiber-reinforced sample CFRPG1H2 with 0.25% graphene-added epoxy resin matrix, aged for 1000 h. The lowest peak strength was observed in the aramid fiber-reinforced sample AFRPG2H2 with 0.50% graphene-added epoxy resin matrix, hydrothermally aged for 1000 h. It was observed that increasing the graphene addition rate reduced the negative effects on aging. It was determined that increasing the graphene ratio by 0.25% had an effect on aging. Full article

Utilizing forestry and agricultural byproducts like wood and hemp residues advance sustainable additive manufacturing (AM), while reducing material costs. This study investigated the development and characterization of wood–sodium silicate composites incorporating hemp hurd and hemp fibers for AM applications. Formulations varied by wood fiber type (unsifted, 40 mesh, and pellet), sodium silicate concentration (50–60 wt%), and hemp hurd content (0–15 wt%). Properties evaluated include particle size and bulk density of the constituent materials, rheological behavior, extrusion performance, composite bulk density, and flexural and compressive strengths. Rheology and extrusion were largely influenced by the liquid content. Mixtures with low liquid content (50 wt% sodium silicate) had high motor power and low viscosity. As liquid content increased, motor power decreased, while viscosity increased up to 55 wt% and then decreased at 60 wt%. Mechanical properties correlated with particle size, where finer particles enhanced strength. A cost analysis was conducted using raw material prices to determine the economic feasibility of each formulation. Finally, the formulations were evaluated based on strength-to-cost ratios, extrudability and processability. The formulation with pellet wood fibers, 55 wt% sodium silicate, and 10 wt% hemp hurd achieved a high ratio of 73.0 MPa/$ while maintaining low motor power. This formulation offered additional benefits which are discussed qualitatively. Full article

Current saw- and pin-type lint-cleaning systems used by the ginning industry have challenges retaining lint quality. The objective of the research was to test a novel pneumatic fractionator for the lint cleaning of an Upland cotton variety that was both saw- and roller-ginned. The process variables tested were initial lint moisture content in the range of 5.5–15% w.b., line pressure in the range of 276–552 kPa, and residence time in the range of 15–45 s. Experiments were conducted based on a central composite design. Models based on response surface methodology (RSM) were developed for final lint moisture, total trash extracted during lint cleaning, and High-Volume Instrument (HVI) fiber quality. The RSM models adequately described the pneumatic fractionation process, as indicated by the coefficient of determination, predicted vs. observed plots, and residual values. The results indicated that the interactions among initial lint moisture content, residence time, and line pressure significantly affected lint quality. At the optimized pneumatic fractionator process conditions, the predicted lint quality attributes were better for both roller- and saw-ginned lint compared to lint cleaned with saw- and pin-type lint cleaners. The upper half mean length increased by 1 mm, the uniformity index was higher by 0.5–1 percentage points, the strength was 1–2 g/tex higher, and the short fiber content was reduced by more than one percentage point. Color grades were better for pneumatic fractionated lint compared to saw- and pin-type lint cleaning methods. Lint value was approximately 4 cents/kg higher for both saw- and roller-ginned pneumatic fractionated lint, compared to lint cleaned using saw- and pin-type lint cleaners. The novel pneumatic fractionator, when compared to industry-standard saw- and pin-type lint cleaners, effectively cleaned lint while retaining fiber quality and removing most of the motes and trash. Full article

Collagen type I has become a practical cornerstone for constructing biologically meaningful barrier interfaces in microfluidic systems. Its fibrillar architecture, native ligand display, and susceptibility to cell-mediated remodeling support epithelial and endothelial polarization, tight junctions, and transport behaviors that are difficult to achieve with purely synthetic barrier interfaces. Recent advances pair these biological strengths with tighter engineering control. For example, ultrathin collagen barriers (tens of micrometers or less) enable faster molecular exchange and short-range signaling; gentle crosslinking and composite designs limit gel compaction and delamination under flow; and patterning/bioprinting introduce alignment, graded porosity, and robust integration into device geometries. Applications now span intestine, vasculature, skin, airway, kidney, and tumor–stroma interfaces, with readouts including transepithelial/transendothelial electrical resistance (TEER), tracer permeability, and image-based quality control of fiber architecture. Persistent constraints include batch variability, long-term mechanical drift, limited standardization of fibrillogenesis conditions, and difficulties scaling fabrication without loss of bioactivity. Priorities include reporting standards for microstructure and residual crosslinker, chips for continuous monitoring, immune-competent co-cultures, and closer collaboration across materials science, microfabrication, computational modelling, and clinical pharmacology. Thus, this review synthesizes the state-of-the-art and offers practical guidance on technological readiness and future directions for using collagen type I as a biological barrier interface in biomimetic microfluidic systems. Full article

Transanal Irrigation (TAI) and Colon Hydrotherapy (CHT) represent emerging therapeutic options that may complement first-line interventions or serve as rescue treatments for chronic constipation and fecal incontinence. Their clinical utility depends on patient characteristics, specific therapeutic goals, device features, and probe type, as well as the procedural setting. This review presents the various pathophysiological contexts in which these techniques can be applied, analyzing their specific characteristics and potential pros and cons. Moreover, these interventions are also considered within a Psycho-Neuro-Endocrino-Immunological (PNEI) framework, given the potential influence of intestinal function and microbiota modulation on the bidirectional communication pathways linking the enteric nervous system, neuroendocrine regulation, immune activity, and global patient well-being. Since there is not yet enough scientific data on this topic, future research should prioritize randomized controlled trials comparing these techniques with other standard treatments (e.g., laxatives or dietary fiber) in defined patient populations. Longitudinal studies will also be essential to clarify long-term safety, potential effects on microbiota, and both risks and benefits. Standardization of technical procedures also remains a critical need, especially regarding professional competencies, operating parameters (e.g., instilled volumes and pressure ranges), and reproducible protocols. Moreover, future investigations should incorporate objective outcome measures, as colonic transit time, stool form and frequency, indices of inflammation or intestinal wall integrity, and changes to microbiome composition. In conclusion, TAI and CHT have the potential to serve as important interventions for the treatment and prevention of chronic constipation and intestinal dysbiosis, as well as their broader systemic correlates, in the setting of bio-integrated medicine. Full article

Human health is profoundly influenced by external factors, with stress being a primary contributor. In this context, the digestive system is particularly susceptible. The prevalence of diseases affecting the small intestine and colon is increasing. Consequently, insoluble plant fibers, such as cellulose and hemicellulose, play a crucial role in promoting intestinal transit and maintaining colon health. Lettuce is a widely consumed leafy vegetable with high nutritional value and has been intensively studied through hydroponic cultivation. This study aims to optimize the cultivation conditions and freeze-drying process of Lugano and Carmesi lettuce varieties (Lactuca sativa L.) by identifying the optimal growth conditions, freeze-drying duration, and sample surface area in order to achieve an optimal percentage of insoluble fibers. Carmesi and Lugano varieties were selected based on their contrasting growth characteristics and leaf morphology, allowing to assess whether treatments and processing conditions have consistent effects on different types of lettuce. The optimal freeze-drying parameters were determined to include a 48 h freeze-drying period, a maximum sample surface area of 144 cm², and growth under combined conditions of supplementary oxygenation and LED light exposure. The optimal fiber composition, cellulose (21.61%), hemicellulose (11.84%) and lignin (1.36%), was found for the Lugano variety, which exhibited lower lignin and higher cellulose contents than the Carmesi variety. The quantification of hemicellulose, cellulose and lignin was performed using the well-known NDF, ADF and ADL methods. Therefore, optimized freeze-dried lettuce powder, particularly from the Lugano variety, presents a high-value functional ingredient for enriching foods and developing nutritional supplements aimed at digestive health. Full article

This study experimentally evaluates the mechanical and microstructural performance of single- and double-layer intraply hybrid composite (IRC) laminates produced using the hand lay-up method, focusing on Glass–Aramid (GA), Aramid–Carbon (AC), and Carbon–Glass (CG) configurations. Tensile, flexural, compressive, and density tests were conducted in accordance with relevant ASTM standards to assess the influence of hybrid type and layer number under field-representative manufacturing conditions. Microstructural investigations were performed using optical microscopy and scanning electron microscopy (SEM) to identify fabrication-induced imperfections and their relationship to mechanical behavior. The results demonstrate that increasing the laminate configuration from single to double layer significantly enhances mechanical performance across all hybrid types. Double-layer AC laminates exhibited the highest tensile strength (330.4 MPa) and Young’s modulus (11.93 GPa), corresponding to improvements of approximately 85% and 59%, respectively, compared to single-layer counterparts. In flexural loading, the highest strength was observed in double-layer CG laminates (97.14 MPa), while compressive strength was maximized in double-layer AC laminates (34.01 MPa), indicating improved stability and resistance to compression-driven failure. Statistical analysis confirmed that layer number is the dominant parameter governing mechanical response, exceeding the influence of hybrid configuration alone. Microstructural observations revealed fiber misorientation, incomplete resin impregnation, and localized voids inherent to manual fabrication. However, these imperfections were consistently distributed across all specimens and did not obscure comparative mechanical trends. Coefficients of variation generally remained below 10%, indicating acceptable repeatability despite non-ideal manufacturing conditions. Full article

Carbon-reinforced epoxy laminated composite (CREC) structures are increasingly utilized in high-speed marine vehicles (HSMVs) due to their high specific strength and stiffness; however, they are frequently subjected to impact loads like slamming and aggressive environmental agents during operation. This study experimentally investigates the Compression After Impact (CAI) behavior of CREC plates with varying lamination sequences under both atmospheric and accelerated aging conditions. The samples were produced using the vacuum-assisted resin infusion method with three specific orientation types: quasi-isotropic, cross-ply, and angle-ply. To simulate the marine environment, specimens were subjected to accelerated aging in a salt fog and cyclic corrosion cabin for periods of 2, 4, and 6 weeks. Before and following the aging process, low-velocity impact tests were conducted at an energy level of 30 J, after which the residual compressive strength was measured by CAI tests. At the end of the aging process, after the sixth week, the performance of plates with different layer configuration characteristics can be summarized as follows: Plates 1 and 2, which are quasi-isotropic, exhibit opposite behavior. Plate 1, with an initial toughness of 23,000 mJ, increases its performance to 27,000 mJ as it ages, while these values are around 27,000 and 17,000 mJ, respectively, for Plate 2. It is thought that the difference in configurations creates this difference, and the presence of the 0° layer under the effect of compression load at the beginning and end of the configuration has a performance-enhancing effect. In Plates 3 and 4, which have a cross-ply configuration, almost the same performance is observed; the performance, which is initially 13,000 mJ, increases to around 23,000 mJ with the effect of aging. Among the options, angle-ply Plates 5 and 6 demonstrate the highest performance with values around 35,000 mJ, along with an undefined aging effect. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) analyses confirmed the presence of matrix cracking, fiber breakage, and salt accumulation (Na and Ca compounds) on the aged surfaces. The study concludes that the impact of environmental aging on CRECs is not uniformly negative; while it degrades certain configurations, it can enhance the toughness and energy absorption of brittle, cross-ply structures through matrix plasticization. Full article

The ultrasonic guided wave method is successfully used for structural health monitoring (SHM) of aircraft structures utilizing PZT (Pb-Zr-Ti based piezoceramic material) sensors for guided wave generation and detection. To increase the mechanical durability of the sensors in operational conditions, this paper demonstrates the feasibility of the integration of PZTs into the Glass fiber/Polymethyl methacrylate (G/PMMA) composite plate and evaluates the possibility of impact damage detection using generated guided waves. Two types of PZT sensors were embedded into different layers during the manufacturing process. Generally, radial mode disc sensors are used for Lamb wave generation, and thickness-shear square-shaped sensors are used for both Lamb and shear wave generation. First, the wave propagation was analyzed considering the sensor type and sensor placement within the layup. The main objective was to propose the optimal sensor network with embedded sensors for successful impact damage detection. Lamb wave frequency tuning of disk sensors and unique vibrational characteristics of integrated shear sensors were exploited to selectively actuate only one guided wave mode. Finally, the Reconstruction Algorithm for the Probabilistic Inspection of Damage (RAPID) was utilized for damage localization and visualization. Full article

Lake Kotokel is one of the largest lakes along the eastern shore of Lake Baikal. Increasing anthropogenic pressure combined with climate variability led to a sharp decline in its ecological condition, culminating in an outbreak of Gaff disease in 2009. Moreover, Lake Kotokel may serve as a source of pollutants to Lake Baikal due to its hydrological connection via a system of rivers. In light of these factors, ongoing research seeks to identify the drivers of ecological degradation in the lake ecosystem and provide a comprehensive assessment of its current environmental status and potential adverse processes. In this study, we report, for the first time, the occurrence of microplastic particles in the surface water and sediments of Lake Kotokel. Mean microplastic concentrations were 0.59 ± 0.25 items/m³ in water and 280 ± 162 items/kg dry weight in sediments, with corresponding average microplastic masses of 2.6 ± 1.4 μg/m³ in water and 1.33 ± 1.21 mg/kg dry weight in sediments. In surface waters, microplastic were predominantly 1–3 mm in size, whereas sediments were dominated by 0.1–1 mm particles. Fibers were the most abundant morphological form, comprising 79.5% and 82.8% of particles in water and sediments, respectively. Five polymer types were identified, with polyethylene terephthalate being the most prevalent. Based on particle abundance and polymer composition, the ecological risk of microplastic in Lake Kotokel was assessed as low to moderate. Full article