Search Results (3,937)

Organophilic acidic magadiites were prepared after an acidic magadiite (A-Mgd) reaction with cetyltrimethylammonium solutions containing different anions, such as cetyltrimethylammonium bromide (C16TMABr), cetyltrimethylammonium chloride (C16TMACl), and cetyltrimethylammonium hydroxide (C16TMAOH). The resulting materials were studied as adsorbents for Eosin Y removal from artificially contaminated solution. Successful preparation of oganophilic A-Mgd was achieved using C16TMAOH solution with an increased basal spacing from 1.21 nm to 3.15 nm and uptake C16TMA amount of 1.16 mmol/g. Meanwhile, no variation in the basal spacing of 1.20 nm occurred using C16TMACl and C16TMA Br solutions with an uptake mount of 0.07 to 0.09 mmol/g, respectively. Other techniques supported the behavior of the counteranion of surfactant solution on the synthesis of organophilic A-Mgd samples. 13C CP/MAS NMR data revealed that C16TMA cations displayed all-trans conformation comparable to C16TMABr solid, and ²⁹Si MAS NMR confirmed the stability of the host silicate layers during the reaction. The specific surface area of A-Mgd was reduced after the intercalation of C16TMA cations from 38 m²/g to 11 m²/g. The removal properties of organophilic samples were investigated under different conditions, including the Eosin Y pH solution, initial concentration, dosage mass, and content of C16TMA cations. The maximum removal amount was 70 mg/g at acidic pH and using A-Mgd prepared from C16TMAOH solution, while the other organophilic A-Mgds exhibited low removal amounts of 3 to 5 mg/g. The regeneration tests indicated that the efficiency was maintained after four reuse tests with a drop of 30 to 50% from the initial value after seven cycles. The adsorber batch design was employed to estimate theoretically the required masses of used samples to treat an effluent volume of 10 L at a removal percentage of 95% at a fixed initial concentration of 200 mg/L. In total, 20 g of organophilic prepared from A-Mgd and C16TMAOH solution was needed, while 243 g of sample prepared from C16TMABr solution was required. This study proposes the development of a cost-effective, sustainable solution for dye-contaminated wastewater treatment. Full article

Runway friction is a critical factor in aircraft safety, affecting braking performance during landing and take-off. This study evaluates friction measurement variability and runway life-cycle dynamics at four typical Australian airports, using GripTester data from calibration strips and operational runways. The results show that friction measurements are influenced by seasonal effects, random errors, and testing equipment tire wear, with greater variability at lower speed (65 km/h) than at higher speed (95 km/h). Analysis of runway friction decay indicates that friction reduction rates are higher in touchdown zones and decelerating rate gradually decrease as friction declines, while regular rubber removal significantly restores friction, sometimes exceeding post-construction levels. Current internationally recommended friction testing intervals may not adequately ensure safety, with a sufficient probability of friction dropping below maintenance planning levels between tests. Based on observed reduction rates, updated intervals of approximately 3000 to 4000 landings are proposed to achieve 90% confidence in maintaining safe friction levels. The findings provide practical guidance for friction management and maintenance scheduling as part of an optimized airport pavement management system. Full article

This paper presents the potential use of sunflower seed hulls (SSH) as a sustainable filler for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites. Ground SSH were incorporated into the PHBV matrix at loadings of 15, 30, and 45 wt% via extrusion and injection molding. The Fourier Transform Infrared Spectroscopy (FTIR) analysis indicated the presence of possible interactions between the filler and the matrix. Mechanical testing revealed a significant increase in stiffness, with the tensile modulus increasing from 2.6 GPa for pure PHBV to approximately 4.5 GPa for the composite containing 45 wt% SSH. However, the tensile strength decreased by approximately 10–40%, while elongation at break dropped to 1.0–1.5%, depending on the SSH dosage, respectively. The thermal analysis indicated that high filler contents suppress crystallization during cooling under laboratory conditions in Differential Scanning Calorimetry (DSC) analysis due to the confinement effect. The key practical advantage is the exceptional improvement in dimensional stability with a processing shrinkage reduction of approximately 80% in the thickness direction. Although water absorption increased with filler loading, biocomposites containing 15–30 wt% SSH exhibited the optimal balance of high stiffness, hardness, and dimensional accuracy. These properties make the developed material a promising option for the production of precise technical molded parts. Full article

Cut flowers of Matthiola incana ‘Mera’ are widely used in floristics but because of wilting, premature leaf yellowing, and flower/inflorescence drying their ornamental value quickly drops. The postharvest performance of this valuable cut flower in terms of symptoms of wilting, relative water content (RWC), carbohydrate content, enzyme activity, and free proline content was studied in relation to the different preservative added to the vases with flowers. The tested preservatives were based on two biocides: 200 mg/L 8-hydroxyquinoline citrate (8-HQC) and nanosilver (NS) in two concentrations, 1 and 5 mg/L, with the addition of 2% sucrose (S). Control inflorescences were kept in distilled water alone. The above preservatives did not prolong vase life, but, on the contrary, decreased it, so flowers placed in distilled water lasted the longest. The contents of both total soluble and reducing sugars increased during flower senescence, reaching the highest level in flowers held in the solution of 5 mg/L NS plus 2% S. Similarly, the content of free proline increased, especially in flowers held in the 8-HQC with 2% S (standard preservative). The contents of hydrogen peroxide (H₂O₂) varied in flowers from different solutions; however, they kept increasing during senescence in flowers from all the treatments. The highest activity of the antioxidative enzymes was found in flowers placed in water. Full article

To address the impact-induced damage to concrete pile foundations of transmission structures caused by nearby blasting vibrations, this study investigates the dynamic splitting tensile behavior of an environmentally friendly lightweight rubberized concrete—Rubber-Toughened Ceramsite Concrete (RTCC)—under impact loading. Quasi-static tests show that the static splitting tensile strength increases first and then decreases with increasing rubber content, reaching a maximum value of 2.01 MPa at a 20% replacement ratio. Drop-weight impact tests indicate that RTCC20 exhibits the highest peak impact force (42.48 kN) and maximum absorbed energy (43.23 J) within the medium strain-rate range. Split Hopkinson Pressure Bar (SHPB) tests further demonstrate that RTCC20 shows the highest strain-rate sensitivity. Overall, RTCC with 20% rubber content provides the best comprehensive performance, achieving a favorable balance between strength and toughness across the entire strain-rate range. These findings offer experimental support for applying RTCC to blast-vibration-resistant transmission structure foundations. Full article

Background: The Identification of Functional Ankle Instability (IdFAI) questionnaire is widely used to screen for functional ankle instability (FAI), but its link to objective landing kinetics in multidirectional sports like netball is not well-understood. This study aimed to (i) compare landing kinetics between idFAI stratified netball players, and (ii) examine associations between IdFAI scores with dynamic postural stability (DPS) indices and peak vertical ground reaction forces (PvGRF) during vertical drop landings. Methods: A cross-sectional exploratory study using a repeated-measures landing protocol was conducted on female university netball players (n = 24), stratified into FAI (n = 12) and non-FAI (n = 12) groups using the IdFAI (≥11 indicating possible FAI). Participants completed 18 unilateral drop jump landings in forward (FW), diagonal (DI), and lateral (LA) directions. Ground reaction forces (GRFs) were recorded to obtain DPS and PvGRF metrics (1000 Hz). Mann–Whitney U tests compared FAI groups, and Spearman correlations assessed associations (p < 0.05). Results: Players with FAI showed greater anteroposterior instability during LA landings (U = 33.5, p = 0.020, ES = 0.65). IdFAI scores correlated moderately with lateral anteroposterior deficits (rs = 0.473, p = 0.020, CI = 0.062–0.746). Conclusions: These findings suggest that players with greater FAI display increased anteroposterior instability during LA landings, with higher IdFAI scores moderately associated with these deficits. Despite the small exploratory, hypothesis-generating sample, the results emphasize the practical relevance of direction-targeted landing-stability training to improve DPS in vertical landings. This may provide insight into ankle-injury risk among FAI netball players, given that LA landings represent a documented ankle sprain mechanism. Full article

Laminate flooring is widely used due to its affordable cost, easy installation, and pleasant esthetics. It is subjected to significant mechanical stress, necessitating a rigorous assessment of its impact resistance. Current standards typically rely on simple methods, such as free fall of a metal ball, not providing information on how the stratified material behaves during impact. This study proposes a modern approach, using an instrumented impact test machine. Tests were carried out with impact energies of 2 J, 3 J, and 5 J. Three tests were performed for statistical relevance. The monitored parameters were maximum force, maximum displacement, impact duration, absorbed energy, indentation diameter. Discussion was focused on influence of flooring thickness and traffic class. The tested materials were commercial brands. Regarding traffic classes, differences became more evident at higher impact energies: class C33 parquet showed larger indentations, while C31 and C32 had smaller values, suggesting that the protective layer in C33 leads to different behavior under impact points. The relevance of this study stems from the fact that, unlike most previous work, the entire testing campaign was conducted using an instrumented impact system, enabling precise and repeatable data acquisition. Full article

The use of resource-constrained Low-Power and Lossy Networks (LLNs), where the IPv6 Routing Protocol for LLNs (RPL) is the de facto routing standard, has increased due to the Internet of Things’ (IoT) explosive growth. Because of the dynamic nature of IoT deployments and the lack of in-protocol security, RPL is still quite susceptible to routing-layer attacks like Blackhole, Lowered Rank, version number manipulation, and Flooding despite its lightweight architecture. Lightweight, data-driven intrusion detection methods are necessary since traditional cryptographic countermeasures are frequently unfeasible for LLNs. However, the lack of RPL-specific control-plane semantics in current cybersecurity datasets restricts the use of machine learning (ML) for practical anomaly identification. In order to close this gap, this work models both static and mobile networks under benign and adversarial settings by creating a novel, large-scale multiclass RPL attack dataset using Contiki-NG’s Cooja simulator. To record detailed packet-level and control-plane activity including DODAG Information Object (DIO), DODAG Information Solicitation (DIS), and Destination Advertisement Object (DAO) message statistics along with forwarding and dropping patterns and objective-function fluctuations, a protocol-aware feature extraction pipeline is developed. This dataset is used to evaluate fifteen classifiers, including Logistic Regression (LR), Support Vector Machine (SVM), Decision Tree (DT), k-Nearest Neighbors (KNN), Random Forest (RF), Extra Trees (ET), Gradient Boosting (GB), AdaBoost (AB), and XGBoost (XGB) and several ensemble strategies like soft/hard voting, stacking, and bagging, as part of a comprehensive ML-based detection system. Numerous tests show that ensemble approaches offer better generalization and prediction performance. With overfitting gaps less than 0.006 and low cross-validation variance, the Soft Voting Classifier obtains the greatest accuracy of 99.47%, closely followed by XGBoost with 99.45% and Random Forest with 99.44%. Full article

Anomaly-based network intrusion detection systems (NIDSs) complement signature-based detection methods to identify unknown (zero-day) attacks. The integration of machine and deep learning enhanced the efficiency of such NIDSs. However, since anomaly-based NIDSs heavily depend on the quality of the training data, the presence of malicious traffic in the training set can significantly degrade the model’s performance. Purging the training data of such traffic is often impractical. This study investigates performance degradation caused by increasing amounts of malicious traffic in the training data. We introduced varying portions of malicious traffic into the training sets of machine and deep learning models to determine which approach is most resilient to unclean training data. Our experiments revealed that Autoencoders, using a byte frequency feature set, achieved the highest F2 score (0.8989), with only a minor decrease of 0.0009 when trained on the most contaminated dataset. This performance drop was the smallest compared to other algorithms tested, including an Isolation Forest, a Local Outlier Factor, a One-Class Support Vector Machine, and Long Short-Term Memory. Full article

The low level of mechanization in the production process of cumin seeds is one of the primary factors limiting their yield and economic efficiency. To enhance the mechanization of cumin seed production, this study focused on cumin seeds as the research subject. Physical parameters of cumin seeds were determined through physical experiments; based on these parameters, a discrete element model of cumin seeds was established, and the shear modulus was calibrated using angle of repose tests. The established model was used to simulate the seeding process of a seed drill, the model’s accuracy was verified by analyzing the seed trajectory, movement velocity, seeding quality, and the dynamic angle of repose of seeds inside the drill. Results indicated that the collision recovery coefficient, static friction coefficient, and rolling friction coefficient between cumin seeds and ABS plastic, stainless steel plates, and other cumin seeds were 0.3, 0.35, and 0.21; 0.49, 0.39, 0.24; and 0.24, 0.38, 0.18, respectively. Calibration via simulated cylinder accumulation tests yielded a deviation of 0.28% between the simulated accumulation angle and the physical accumulation angle at a shear modulus of 100 MPa; the simulated seed trajectory during dispensing closely matched physical dispensing tests. The average deviation in particle drop velocity within the bridge channel region was 4.23%, with a maximum deviation of 6.07%; the average deviation in dynamic packing angle from start to finish for the particle group was 2.84%, with a maximum deviation of 4.18%; and the average mass discharged from the 14 simulated seed nozzles was 0.0446 g, compared to 0.043 g in physical tests, with a deviation of 3.72%. These results demonstrate the high accuracy and reliability of the established cumin discrete element model and its parameters, providing technical support for the design and optimization of full-process mechanical cumin production systems. Full article

Dry eye disease is a common condition in which tear production or quality is insufficient to lubricate the eyes properly. Standard treatment usually involves lubricating eye drops. In this study, we assessed the human health risks, including both non-carcinogenic and carcinogenic effects, associated with long-term exposure to the chemical elements arsenic (As), cadmium (Cd), cobalt (Co), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) in eye drops used in Brazil. The results indicated that the Co concentration (1.1048 mg/kg) in the eye drops sample 5 exceeded the limit established by the ICH Q3D (R2) guideline for parenteral products (0.5000 mg/kg). Additionally, As levels in eye drop samples 2, 8–10, 12, 13, and 16, as well as Cd levels in samples 2, 3, 8–10, and 12, exceeded the limits established by the Brazilian Pharmacopoeia for parenteral administration (0.0500–0.0532 mg/kg). The main health risk appears to come from oral exposure, as the drug can drain into the nasal cavity via the nasolacrimal duct and then be absorbed through the gastrointestinal tract. While none of the tested eye drops posed non-carcinogenic risks, carcinogenic risks from oral exposure to As and Cd were identified, with overall risk levels exceeding acceptable thresholds. These findings emphasize the need for strict regulation and continuous monitoring of these products to reduce health risks and prevent long-term damage. Full article

This study examined the trial-to-trial reliability and usefulness of the Output Sports inertial measurement unit (IMU) in measuring reactive strength index (RSI) derived from the Drop Jump (DJ) and 10-5 rebound jump test (10-5 RJT). Twenty-three male elite intercounty hurlers (mean ± SD; age: 24.3 ± 3.7 years, mass: 88.0 ± 6.3 kg, height: 183.8 ± 5.8 cm, experience at elite level: 5.8 ± 3.8 years) performed three trials each of the DJ and 10-5 RJT, on familiarisation and testing days. There was one week between familiarisation and testing. Reliability was determined by intraclass correlation (ICC) and coefficient of variation (CV) analyses. Usefulness was assessed by comparing typical error (TE) with the smallest worthwhile change (SWC). Both the DJ and 10-5 RJT were reliable in determining RSI, with CV ≤ 10% and ICC ≥ 0.8. The TE was 0.09 and 0.08 for the DJ and 10-5 RJT, respectively. Both tests were unable to detect the SWC, rating them as ‘marginal’; however, they were rated as ‘good’ in detecting moderate change in RSI. The Output Sports IMU is reliable in determining RSI for the DJ and 10-5 RJT; however, it is unable to detect the SWC. Future research must determine validity of the Output Sports IMU in measuring RSI. Full article

We examined the acute effects of flywheel eccentric overload (FEO) on countermovement jumps (CMJs), changes of direction (COD), and isometric mid-thigh pulls (IMTPs) in top-level team sports athletes (three females and seven males). FEO was carried out by performing 3 × 6 reps with 0.025 kg·m² inertia and a 2 min passive rest period. Its post-activation potentiation was compared to a control warm-up. Performance was tested at 0, 3, and 6 min post-intervention. Significant improvements were reported in the COD5m times for the left (F = 8.38, p < 0.001, ES = 1.92) and right legs (F = 11.3, p < 0.001, ES = 2.24), as well as for CMJ height (F = 12.4, p < 0.001, ES = 2.35). Significant differences were observed in COD5m between baseline and 3 min (p < 0.001, ES = 0.99 and p = 0.003, ES = 1.25) and 6 min (p = 0.04, ES = 1.19 and p < 0.001, ES = 1.09) for the left and right legs, respectively. Jump height increased significantly at 3 min (p < 0.001, ES = 1.62) and remained elevated at 6 min (p < 0.001, ES = 1.02). CMJ peak power (CMJPP) decreased significantly (F = 6.4, p = 0.002, ES = 1.68), with a drop at 0 min (p = 0.024, ES = 0.85) and a return to baseline at 3 min (p = 0.002, ES = 1.35). No significant effects were found for the CMJ eccentric rate of force development (CMJRFDecc) or IMTP. It was found that FEO can acutely enhance jumping and changes of direction but not strength in elite team sports athletes. A three-minute rest appears to maximize these effects. Full article

A spring–dashpot model, consisting of a spring branch and two Maxwell (named long- and short-term) branches, was used to simulate stress drop during the relaxation stages of multi-relaxation (MR) tests. This work shows that the stress drop at relaxation in a deformation range around the peak stress could be closely simulated without changing the parameter values for the short-term branch. This possibility was confirmed using three ethylene/1-hexene copolymers and one ethylene homo-polymer, among which the main differences are mass density and short-chain branch (SCB) content. The work examined the influence of SCB content and mass density on the stiffness of the two Maxwell branches, and the results showed that, unlike the long-term branch counterpart, stiffness of the short-term branch is not a monotonic function of the SCB content or the mass density. This led to a discussion on the possible relationship between the stiffness of the two Maxwell branches and the deformation resistance of the amorphous phase at different locations of the microstructure, i.e., in the interlamellar region and as part of the network structure. The paper concludes that a combination of the MR test and the spring–dashpot model could provide information that is related to the stiffness in different parts of PE’s amorphous phase, though further work is needed to verify this conclusion. Full article

Evidence for flipped-classroom learning in the health professions is growing, yet its advantage over lectures when transferable learning is tested remains unclear. We conducted a cross-sectional, inter-institutional comparison of two European programs (anonymized as Center A—lecture-based; Center B—flipped classroom). Students in Years 1 to 3 completed two anatomy examinations (0–10 scale): their own institutional exam and the partner’s exam. A 10-item Likert questionnaire produced a 0 to 10 Global Satisfaction Index. Analyses included Welch’s t test, effect sizes, and 95% confidence intervals. Own scores were comparable between centers (mean difference ≈ +0.10; p = 0.66; Hedges’ g ≈ 0.07). Cross scores strongly favored Center B [difference ≈ −2.40; 95% CI −2.72 to −2.07; p < 10⁻³²; g ≈ −1.87]. By course, the Own → Cross drop was large in Center A across Years 1 to 3, moderate in Center B, and nearly absent in Year 3. Satisfaction was higher in Center B; internal consistency of the 10-item scale was modest overall (α ≈ 0.61). When assessment demands transfer to an unfamiliar format, flipped-classroom exposure confers a large performance advantage and higher satisfaction, while differences vanish on familiar exams. The findings support aligning anatomy curricula with active, application-focused learning and mixed-format assessment to promote durable, transferable learning. Full article