Search Results (144)

Runway microtexture is a key parameter governing pavement friction. In recent years, several microtexture assessment methods have been developed; however, understanding of microtexture evolution under operational conditions, as well as the effects of maintenance techniques, remains limited. In this study, a runway at an Australian airport was investigated using laser profilometry. Measurements were conducted across multiple transverse sections, including aircraft touchdown and mid-runway zones. Microtexture deterioration rates were evaluated based on the estimated number of tire–pavement contacts, and aggregate polishing was assessed at different locations. Measurements were also performed after rubber contamination removal and rejuvenation treatments. The results indicate that approximately 25% of total microtexture reduction can be attributed to surface polishing, with a lower contribution in touchdown zones due to the protective effect of rubber deposits. A non-linear degradation trend was observed in touchdown zones, where approximately 1100 tire contacts reduced average microtexture roughness from 18 μm to 11 μm. Rubber removal effectively restored microtexture close to its original levels across the runway width. A rejuvenation treatment with a covering of fine sand initially improved microtexture; however, rapid deterioration occurred due to loss of the sand coating. These findings improve the understanding of microtexture evolution under operational runway conditions, albeit only at a case study level, and support more effective runway maintenance planning and intervention strategies. Full article

Nanocomposites consisting of titanium carbonitride nanoparticles (TiCN) and epoxy resin were fabricated and studied as the filler content was varied. Nanocomposites’ structural investigation was conducted via X-ray Diffraction technique (XRD), while their morphology was examined by employing Scanning Electron Microscopy (SEM). Viscoelastic mechanical properties were assessed by Dynamic Mechanical Thermal Analysis (DMTA). Results revealed the reinforcing ability of TiCN nanoparticles. The dielectric characterization of the nanocomposites was carried out using Broadband Dielectric Spectroscopy (BDS) over a wide frequency and temperature range. Dielectric spectroscopy revealed two relaxation processes related to the polymer matrix: the α-relaxation, associated with the glass-to-rubber transition, and the β-relaxation, associated with the rearrangement of side polar groups. In addition, in the low-frequency–high-temperature region, interfacial polarization (IP) was observed. IP is related to the presence of nanoparticles and to the accumulation of unbound charges at the system’s interface and includes contributions from a dipolar process and charge migration (conductivity). Alternating current conductivity generally increases with filler content, though it is also affected by frequency and temperature. Conductivity could influence Electrode Polarization (EP), which often masks the dipolar process of IP. A simple method for removing the EP effect is formulated and tested. Full article

Plaque-disclosing agents are widely used to enhance visualization of dental biofilm. However, their chromogenic components may adhere to enamel surfaces, resulting in transient extrinsic discoloration. This study evaluated the extent and short-term recovery of such discoloration and compared three removal modalities in terms of enamel color change (CIEDE2000, ΔE₀₀), surface roughness (Ra), and gloss (GU). Extracted human anterior teeth with intact buccal enamel were stained using an erythrosine-based disclosing agent and randomly allocated into three groups (n = 15): manual brushing with conventional toothpaste, rubber-cup polishing with a perlite-containing paste (1000 rpm, 5 s), or erythritol-based air-polishing (5 s; 50% power/100% water). ΔE₀₀ was measured at baseline, immediately after cleaning, and after 1 week of storage in artificial saliva. Ra and GU were recorded at baseline and post-cleaning. Data were analyzed using appropriate tests (p < 0.05). All modalities were associated with a reduction in visible discoloration without significantly affecting Ra or GU (p > 0.05). Immediate ΔE₀₀ values remained above commonly reported acceptability thresholds, indicating residual discoloration. Partial color recovery occurred after artificial saliva storage. Within the limitations of this study, the findings indicate no statistically significant differences among the tested procedures, without evidence of superiority of any single modality. Full article

Tyre and road wear particles (TRWPs) represent one of the most significant yet under-recognised sources of global microplastic pollution, contributing up to 28% of total emissions. Generated from the complex interaction between vehicle tyres and road surfaces, TRWPs are chemically diverse, morphologically heterogeneous, and environmentally persistent, making their detection and management particularly challenging. This review provides a critical synthesis of current knowledge on TRWP generation mechanisms, influenced by tyre composition, road types, and vehicle operation, and their environmental dispersion through air, stormwater runoff, snow removal, and roadside deposition. The chemical and physical complexity of TRWPs—often composed of rubber, bitumen, road paint, and heavy metals—necessitates multifaceted analytical approaches. We synthesise current advancements in TRWP identification techniques, including microscopy, micro-spectroscopy, and thermal desorption methods, while benchmarking their applicability using ISO standards. Furthermore, we develop an integrated framework synthesising current classification schemes, detection strategies, and regional policy responses for TRWP assessment. By identifying analytical and regulatory gaps, this review highlights the need for harmonised methodologies, improved analytical comparability, and coordinated policy interventions to address the environmental and health implications of TRWPs. Full article

As the demand for clean water grows, the strategic management of water resources has become increasingly critical. However, the depletion of these resources is being accelerated by anthropogenic pollutants and resultant internal pipe corrosion within distribution networks. Conventional water treatment methods are characterized by high energy consumption, rendering them impractical in environments lacking a continuous external power supply. Consequently, innovative, self-sustained technologies for simultaneously monitoring fluid conditions and purifying water are a necessity. In this work, we present a water-driven triboelectric nanogenerator (W-TENG) used for energy harvesting and water-quality monitoring within pipe networks. Composed of a silicone rubber tube and aluminum electrodes, the optimized W-TENG achieved an open-circuit voltage of 58 V, short-circuit current of 1.1 µA, and 59.5 mW/m² at a 10 MΩ load. The W-TENG distinguishes pH levels and liquid types based on electrical outputs. Notably, a parallel connection of two W-TENGs enhanced electrical energy by 214% compared to the sum of two units. As an application, a self-powered electrochemical deposition was conducted and copper ions were successfully removed using energy stored in a 1 mF capacitor. These results indicate that the W-TENG is expected to be utilized as a self-powered platform for simultaneous water purification and real-time infrastructure monitoring. Full article

This study presents the development and first manufacturing realization of the ECOTIRE concept, a modular and sustainable tire system featuring a removable tread mechanically interlocked with a reusable casing. The concept aims to reduce rubber waste and improve recyclability by eliminating adhesive bonding and enabling tread replacement. Building on previous experimental and numerical studies that validated the interlocking performance, this work focuses on producing a scaled prototype using a low-cost molding process, which can serve as the basis for accessible and sustainable manufacturing. VMQ silicone rubber was selected as an eco-friendly material due to its durability, thermal stability, and processing versatility. A custom two-part aluminum mold was designed to replicate the optimized interlocking geometry, enabling accurate casting, curing, and assembly. The resulting prototype achieved precise fit, dimensional uniformity, and easy disassembly, confirming the manufacturing feasibility of the ECOTIRE concept and demonstrating its potential to support circular economy strategies through reduced material waste and extended tire component lifetimes. Full article

Detecting Escherichia coli on food preparation and processing surfaces is critical for ensuring food safety and preventing foodborne illness. This study focuses on detecting E. coli contamination on common food processing surfaces using UV-C fluorescence imaging and deep learning. Four concentrations of E. coli (0, 10⁵, 10⁷, and 10⁸ colony forming units (CFU)/mL) and two egg solutions (white and yolk) were applied to stainless steel and white rubber to simulate realistic contamination with organic interference. For each concentration level, 256 droplets were inoculated in 16 groups, and fluorescence videos were captured. Droplet regions were extracted from the video frames, subdivided into quadrants, and augmented to generate a robust dataset, ensuring 3–4 droplets per sample. Wavelet-based denoising further improved image quality, with Haar wavelets producing the highest Peak Signal-to-Noise Ratio (PSNR) values, up to 51.0 dB on white rubber and 48.2 dB on stainless steel. Using this dataset, multiple deep learning (DL) models, including ConvNeXtBase, EfficientNetV2L, and five YOLO11-cls variants, were trained to classify E. coli concentration levels. Additionally, Eigen-CAM heatmaps were used to visualize model attention to bacterial fluorescence regions. Across four dataset groupings, YOLO11-cls models achieved consistently high performance, with peak test accuracies of 100% on white rubber and 99.60% on stainless steel, even in the presence of egg substances. YOLO11s-cls provided the best balance of accuracy (up to 98.88%) and inference speed (4–5 ms) whilst having a compact size (11 MB), outperforming larger models such as EfficientNetV2L. Classical machine learning models lagged significantly behind, with Random Forest reaching 89.65% accuracy and SVM only 67.62%. Overall, the results highlight the potential of combining UV-C fluorescence imaging with deep learning for rapid and reliable detection of E. coli on stainless steel and rubber conveyor belt surfaces. Additionally, this approach could support the design of effective interventions to remove E. coli from food processing environments. Full article

Vulcanized NR-SBR is widely used in vehicle components; however, its irreversible crosslinking limits recyclability and contributes to the large number of tires discarded annually worldwide, and in this context, this work presents an experimental comparative assessment of the tribological behavior of conventional tire rubber and silicone VMQ, motivated by a wheel concept based on a detachable tread aimed at improving durability and sustainability rather than proposing an immediate material substitution. Wear and friction behavior were investigated under abrasive and self-friction conditions using pin-on-disk testing with an abrasive counterpart representative of asphalt, supported by optical and scanning electron microscopy. The results show that NR-SBR undergoes severe abrasive and erosive wear, characterized by deep and irregular wear tracks, pronounced fluctuations in the dynamic friction coefficient, and strong sensitivity to load and sliding speed, particularly during the initial stages of track formation. In contrast, VMQ exhibits mild abrasive wear dominated by viscoelastic deformation, leading to shallow and stable wear tracks, lower friction coefficients, and significantly reduced material loss once the contact track is fully developed. These differences are attributed to the distinct mechanical responses of the elastomers, as the higher hardness and limited strain capacity of rubber promote micro-tearing and unstable material removal, while the high elasticity of silicone enables stress redistribution and stable contact conditions under abrasive loading. UV aging increases stiffness of rubber, resulting in reduced wear and friction, while silicone remains largely unaffected after 750 h due to the stability of its Si–O–Si backbone. Self-friction tests further indicate that smooth silicone sliding against rubber yields the lowest friction values, highlighting a favorable material pairing for detachable tread concepts. Factorial design analysis confirms material type as the dominant factor influencing both wear and friction. Overall, for the specific materials and operating conditions investigated, VMQ demonstrates higher durability, greater tribological stability, and improved aging resistance compared to NR-SBR, providing experimental evidence that supports its potential for long-life, more sustainable detachable tread applications. Full article

Agave lechuguilla fibers exhibit high tensile strength, low density and durability, but their use in natural rubber composites is underexplored. This study investigates alkaline-treated fibers (149–180 µm) as reinforcements for natural latex. Fibers were pretreated with a methanol–acetone mixture, followed by immersion in 10% NaOH at 70 °C for 1 h, removing lignin and hemicellulose as confirmed by FTIR and SEM. Thermogravimetric analysis showed three weight-loss stages: moisture/volatiles (9.4%), hemicellulose (peak at 341 °C), and cellulose/lignin (peak at 482 °C), with <3% residue above 500 °C. Treated composites exhibited enhanced tensile strength (4.68 ± 1.2 MPa vs. 1.3 ± 0.8 MPa for untreated) and elongation at break (530 ± 51% vs. 452 ± 32%). Hardness increased from 21.8 (neat latex) to 30.3, and compression resistance was improved. Optical microscopy revealed strong fiber–matrix adhesion with uniform dispersion. Alkaline treatment enhances interfacial bonding and mechanical performance, making A. lechuguilla fibers a sustainable reinforcement for eco-friendly composites in automotive, construction, and packaging sectors. 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

Under the DC field, live contamination is more likely to deposit on the surface of insulators due to the action of the external electric field. The deposition of dirt on the surface of Ultra High Voltage (UHV) insulators can lead to the occurrence of flashover phenomena, causing significant economic losses. Due to the particularity of UHV insulators, many traditional surface anti-pollution technologies designed for normal voltage insulators are not applicable to them. In order to prevent the harm of contamination accumulation affecting the safe operation of transmission lines, in this study, tetragonal BaTiO₃ was mixed into room-temperature vulcanized silicone rubber for the first time to prepare a composite coating with piezoelectric properties. This coating can use the piezoelectric effect to remove the contamination adhering to the surface of UHV insulators under a DC field. In this study, the piezoelectric properties of the prepared tetragonal BaTiO₃ were verified through material characterization. The results show that the introduction of piezoelectric fillers can significantly accelerate the dissipation of charges on the insulator surface under slight disturbances, which helps to reduce the accumulation of charged pollutants on the insulator surface. The anti-pollution performance under electric field conditions was verified through a simulation experimental device. Finally, through experiments in a real converter station environment, the anti-pollution effect of the insulator under actual working conditions was verified. Full article

Triclosan (TCS), a persistent antimicrobial and endocrine-disrupting compound, is commonly found in surface and groundwater due to incomplete removal by conventional wastewater treatment. This study evaluated its fate in authentic rainwater runoff collected from a state road using rubber tiles made from recycled tires that were either uncoated (RRT) or coated with TiO₂ via the sol–gel method (SGT). Pollutants were analyzed by a high-resolution liquid chromatography–quadrupole time-of-flight mass spectrometry system (LC/MS QTOF) before and after treatment in a flat-plate cascade reactor under UV-A irradiation. After 120 min SGT achieved >50% TCS removal, while RRT achieved ~44%. Further analysis identified degradation products (chlorocatechole, quinone, and transient dioxin-like species). ECOSAR predictions indicated moderate to high toxicity for some degradation products, but their transient and low-abundance detection suggests that photocatalysis suppresses accumulation, ultimately yielding less harmful products such as benzoic acid. These findings highlight the dual role of TiO₂-coated rubber tiles: improving material durability while enabling photocatalytic degradation. Full article

Cadmium {Cd (II)} poses a high risk to ecological security and human health due to its high toxicity, easy migration and difficult degradation. Using waste rubber seed shell biochar (RSSB) as the carrier material of nZVI may inhibit the caking oxidation of zero-valent iron and improve the removal efficiency of Cd (II) from water. Through a series of batch experiments, the adsorption mechanism of modified biochar on Cd (II) clarified that the removal effect of nano-zero-valent iron-rubber seed shell biochar (nZVI-RSSB) on heavy metals in water was better than that of RSSB. The results showed that when the dosage of complex biochar was 80 mg, the initial concentration of Cd (II) was 50 mg/L, and the solution pH was 6, the maximum adsorption capacity of nZVI-RSSB for Cd (II) reached 30.42 mg/g, compared with the RSSB of 13.32 mg/g. The adsorption kinetics model showed that chemisorption and physical adsorption existed simultaneously. The results of the in-particle diffusion model show that the adsorption process may be divided into two stages. The Langmuir competitive adsorption model was followed. Electrostatic adsorption and precipitation/co-precipitation could be the main ways for the removal of Cd (II) by composite materials. Meanwhile, the synergistic adsorption of nZVI-RSSB composites with multiple metals in actual water showed its application potential in water pollution control. Hence, the nZVI-RSSB not only successfully inhibits the caking oxidation of zero-valent iron, but also effectively improves the removal efficiency of heavy metals from water. Full article

Waste glass recycling generates waste streams such as fine glass fraction, waste ceramics containing fine glass, and waste polyethylene plastics. All of the aforementioned streams contain contaminants of organic and inorganic origin that are difficult to remove. This research was conducted to determine technological processes aimed at achieving a circular economy (CE) in the recycling of waste glass. Foam glass was made from the fine-grained, multicolored fraction of contaminated glass, an effective method for recycling glass waste at a low cost. A frothing system based on manganese oxide (MnO₂) and silicon carbide (SiC) was proposed, and an optimum weight ratio of MnO₂/SiC equal to 1.0 was determined. The possibility of controlling the process to achieve the desired foam glass densities was demonstrated. Statistical analysis was used to determine the effect of the MnO₂/SiC ratio and MnO₂ content on the density of the resulting foam glass products. Waste ceramics contaminated with different-colored glass were transformed into ceramic–glass granules. The characteristic temperature curve of the technological process was determined. The metal content in water extracts from ceramic–glass granules and pH value indicate their potential use for alkalizing areas degraded by industry and agriculture. Waste polyethylene-based plastics were converted into polyethylene waxes by thermal treatment carried out in two temperature ranges: low temperature (155–175 °C) and high temperature (optimum in 395 °C). The melting temperature range of the obtained waxes (95–105 °C) and their FTIR spectral characteristics indicate the potential application of these materials in the plastics and rubber industries. The integrated management of all material streams generated in the glass recycling process allowed for the development of a CE model for the glass recycling plant. Full article

This paper presents the results of a survey of the designed biological wastewater treatment facilities of an enterprise specializing in the production of rubber products. The aim of the study was to assess the efficiency of wastewater treatment systems under the conditions of a salvo discharge of industrial effluents that differ in composition from domestic wastewater. The analysis covered the parameters of water supply, water disposal, and wastewater characteristics at various stages of treatment. Three samples were taken: after washing the premises (WW1), at the inlet to the treatment facility (WW2), and at the outlet after treatment (WW3). Experimental assessment of the purification efficiency for key pollutants showed a high degree of removal of surfactants (91.2%), oil products (84.4%), and COD (63.4%). However, phosphorus–phosphate turned out to be significantly higher than the norm—2.32 mg/L with an acceptable level of 0.2 mg/L—which corresponds to an excess of 11.6 times. A low degree of ammonium nitrogen removal was also revealed—62%. Calculations showed a critically high ratio of COD/BOD5 = 5.1 with the recommended <2.6, which indicates a small share of biodegradable substances and the need to implement physical and chemical treatment methods. The absence of the characteristic smell of household wastewater and the presence of black inorganic sediment confirm the toxicity of emerging pollutants for activated sludge. It is concluded that the installed biological treatment system cannot cope with the salvo loads of industrial wastewater. Optimization measures are proposed: preliminary local treatment, dosed feed, and a separate treatment system. Full article